JP3749307B2 - Copy apparatus and copy control method - Google Patents

Description

但し、各記号の意味は次の通りである。
【００６３】
ＬＭ：倍率スロープ係数。ネガフィルムの種類とプリントサイズとで定まる引き伸ばし倍率に応じて予め設定されている。
【００６４】
ＣＳ：カラースロープ係数。ネガフィルムの種類毎に用意されており、アンダ露光用とオーバ露光用とがある。プリントすべき画像コマの平均濃度が標準ネガ濃度値に対してアンダかオーバかを判定してアンダ露光用とオーバ露光用の何れかを選択する。
【００６５】
ｄＮ：標準ネガ濃度値。
ｄ ：プリントすべき画像コマの画面平均濃度値
ＰＢ：標準カラーペーパに対する補正バランス値。カラーペーパの種類に応じて決定される。
【００６６】
ＬＢ：標準焼付レンズに対する補正バランス値。焼付けに用いるレンズの種類に応じて決定される。
【００６７】
ＭＢ：光源光量の変動やペーパ現像性能の変化に対する補正値（マスタバランス値）。
【００６８】
ＮＢ：ネガフィルムの特性によって定まるネガバランス（カラーバランス）値。
【００６９】
Ｋ₂ ：カラー補正量。
Ｋ₁ ：濃度補正量。
【００７０】
またステップ１５８では、上記により演算した露光量Ｅ₀ に基づいて、色補正フィルタ２８を構成するＣ、Ｍ、Ｙの各フィルタの位置、及び露光時間ｔ₀ （ブラックシャッタ３６の開放時間）を決定する。このステップ１５８は本発明の露光量演算手段に対応している。
【００７１】
次のステップ１６０では露光量補正値ΔＥを取込み、ステップ１５８で演算した露光量Ｅ₀ を取込んだ露光量補正値ΔＥによって補正する。なお、露光量補正値ΔＥは初期値が０（＝補正無し）とされており、後述する露光量補正処理によって値が設定される。本第１実施形態では、露光量補正値ΔＥとして、露光時間ｔ₀ を補正するための露光時間補正値Δｔを用いており、例として次の（２）式に従って、補正済露光時間ｔを求める。
【００７２】
ｔ＝ｔ₀ ＋Δｔ …（２）
ステップ１６２では、ステップ１６０で補正した露光量（露光時間ｔ₀ が補正された後の露光量Ｅ）を、ステップ１５６で記憶したネガ画像データと対応させて記憶手段９４Ｅに記憶する。ステップ１６４では、補正後の露光量Ｅに基づいて色補正フィルタ２８及びブラックシャッタ３６を作動させる。具体的には、色補正フィルタ２８の各フィルタがステップ１５８で決定した位置へ移動するようにドライバ９６に指示し、更にブラックシャッタ３６を補正済露光時間ｔに相当する時間だけ開放させる。これにより、露光位置に位置決めされているネガフィルム１４の画像が、補正後の露光量Ｅで印画紙１６に露光される。
【００７３】
次のステップ１６６では、ネガフィルム１４に記録されている全ての画像の露光を行ったか否か判定する。判定が否定された場合にはステップ１５０へ戻り、上記処理を繰り返す。そして、上記判定が肯定されると処理を終了する。
【００７４】
次に図４のフローチャートを参照し、本第１実施形態に係る露光量補正処理について説明する。なお、この図４のフローチャートは、上述した露光処理によって画像が露光された印画紙１６が、プロセッサ部６４の各処理槽内に貯留されている処理液に浸漬されて処理され（これにより、先の露光処理で露光された画像が現像される）、印画紙１６の先端部が乾燥部７２から排出されると、割込みがかかって制御部９４のＣＰＵ９４Ａで実行される。
【００７５】
ステップ１７０では印画紙１６を搬送する。ステップ１７２では、ＣＣＤイメージスキャナ７６から出力される信号を監視することにより、印画紙１６上に形成された画像（プリント画像）の位置を判断し、ＣＣＤイメージスキャナ７６による印画紙１６の測光位置にプリント画像が到達したか否か判定する。判定が否定された場合にはステップ１７０に戻り、印画紙１６の搬送を継続する。
【００７６】
ステップ１７２の判定が肯定されると、ステップ１７４で印画紙１６の搬送を停止させ、測光位置に到達したプリント画像を測光位置に位置決めする。ステップ１７６では測光位置に位置決めした画像をＣＣＤイメージスキャナ７６によって測光し、ＣＣＤイメージスキャナ７６から増幅器１０４、Ａ／Ｄ変換器１０６、３×３マトリクス回路１０８を介して出力されるＲ、Ｇ、Ｂ毎のプリント画像データ（本発明の第２の画像データに相当）を取込む。
【００７７】
また、ステップ１７８では、記憶手段９４Ｅに記憶されているネガ画像データ及び露光量データのうち、ステップ１７６でプリント画像データを取込んだプリント画像に対応するネガ画像データ及び露光量データを検索し、取込む。このステップ１７８から、後で説明するステップ１９２迄の処理は本発明の演算手段に対応している。
【００７８】
なお、先に説明した露光処理のステップ１５６、１６２において、各ネガ画像に対応するネガ画像データ及び露光量データを識別するための識別情報と対応させてネガ画像データ及び露光量データを記憶するようにすれば、プリント画像に対応するデータの検索が容易になるので好ましい。この識別情報の設定及びデータの検索は、例として以下のようにして行うことができる。すなわち、第１のカウンタ及び第２のカウンタを設け、ネガ画像を１コマ読み取る毎に第１のカウンタをカウントアップすると共に、ネガ画像データ及び露光量データを記憶する際には、識別情報として第１のカウンタのカウント値を対応させて記憶する。また、第２のカウンタはプリント画像を１コマ読み取る毎にカウントアップする。
【００７９】
これにより、プリント画像に対応するデータの検索は、第２のカウンタの現在のカウント値に一致する識別情報と対応されて記憶されているネガ画像データ及び露光量データを検索することで実現できる。なお、第１のカウンタ及び第２のカウンタは、処理の切れ目を判定するための所定の条件（例えば１本のネガフィルム１４に記録された全ての画像の露光が終了した、或いは露光済み印画紙１６が露光室４２から全て排出された等）を満足したときに、カウント値を０にクリアすればよい。
【００８０】
ところで、本実施形態では制御部９４のＲＯＭ９４Ｂに、図５（Ｂ）に実線で示すように、所定露光量ｅ_T で露光したときのネガ濃度ｄとプリント濃度Ｄとの関係が予め記憶されている。このネガ濃度ｄとプリント濃度Ｄとの関係は、プリンタプロセッサ１０が標準状態となるように（処理液の状態、光源２６の光量等の各種処理条件が標準状態での処理条件となるように）調整した後に、ＣＣＤイメージセンサ８６によって予め画素毎に濃度を測定した所定のネガ画像を所定露光量ｅ_T で印画紙１６に露光し、プロセッサ部６４で現像等の処理が行われた印画紙１６のプリント画像の濃度を画素毎に測定する実験を行うことによって求められたものである。
【００８１】
この関係はプリンタプロセッサ１０が標準状態のときのネガ濃度ｄとプリント濃度Ｄとの関係を表しており、以下ではこの関係をプリント理想特性と称する。次のステップ１８０ではこのプリント理想特性を取込む。
【００８２】
なおＲＯＭ９４Ｂには、図５（Ａ）に示すように露光量Ｅとプリント濃度Ｄとの関係も記憶されている。この露光量Ｅとプリント濃度Ｄとの関係についても、上述のようにプリンタプロセッサ１０が標準状態となるように調整した後に、所定濃度ｄ₀ のネガ画像に対し、露光量Ｅを様々に変化させて印画紙１６への焼付露光を繰り返し、プロセッサ部６４で現像等の処理が行われた印画紙１６の各プリント画像の濃度を測定する実験を行うことによって求められたものである。
【００８３】
この露光量Ｅとプリント濃度Ｄとの関係は、前述のプリント理想特性と共に、請求項２に記載の「標準状態とされた複写手段により原画像を複写材料に露光させ該複写材料に標準複写画像を形成させた場合の、原画像の画像特徴量と露光量と標準複写画像の画像特徴量との関係」に対応している。
【００８４】
ステップ１８２では、先のステップ１７８で取込んだ露光量データが表す露光量ｅが、前記プリント理想特性を求めたときの所定露光量ｅ_T に一致しているか否か判定する。判定が肯定された場合にはステップ１８６へ移行し、ステップ１８６以降では、先に取込んだプリント理想特性をそのまま用いて処理を行う。
【００８５】
一方、ステップ１８２の判定が否定された場合にはステップ１８４へ移行し、先に取込んだプリント理想特性を、ステップ１７８で取込んだ露光量データが表す露光量ｅに応じて修正する。
【００８６】
具体的には、ＲＯＭ９４Ｂに記憶されている露光量Ｅとプリント濃度Ｄとの関係（図５（Ａ）参照）に基づき、露光量ｅで前記所定濃度ｄ₀ のネガ画像の露光を行ったときのプリント濃度Ｄ_x を求める。例として図５（Ａ）に示すように、露光量データが表す露光量がｅ₁ であった場合にはプリント濃度Ｄ_x として濃度Ｄ₁ が求まり、露光量データが表す露光量がｅ₂ であった場合にはプリント濃度Ｄ_x として濃度Ｄ₂ が求まる。
【００８７】
次に、理想プリント特性を表す図表上でネガ濃度がｄ₀ 、プリント濃度がＤ_x の点を通るようにプリント理想特性を平行移動させる。例えばプリント濃度Ｄ_x の値が濃度Ｄ₁ であった場合には、ネガ濃度がｄ₀ 、プリント濃度がＤ₁ の点Ｐ₁ を通るようにプリント理想特性が平行移動される（図５（Ｂ）の一点鎖線）。また、プリント濃度Ｄ_x の値が濃度Ｄ₂ であった場合には、ネガ濃度がｄ₀ 、プリント濃度がＤ₂ の点Ｐ₂ を通るようにプリント理想特性が平行移動される（図５（Ｂ）の二点鎖線）。これにより、露光量データが表す露光量ｅで露光を行ったときのプリント理想特性が得られる。
【００８８】
ステップ１８４の処理を行うとステップ１８６に移行するが、この場合には、ステップ１８４の処理によって得られたプリント理想特性を用いてステップ１８６以降の処理が行われる。
【００８９】
なお、上述したように所定露光量ｅ_T で露光を行ったときのプリント理想特性のみを記憶しておき、このプリント理想特性を平行移動して用いることに代えて、図５（Ｃ）に各々実線で示すように、互いに異なる複数の露光量（例えばｅ_a 、ｅ_b 、ｅ_c ）で露光を行ったときのプリント理想特性を各々求めて記憶しておくようにしてもよい。この場合、プリント理想特性を記憶するために必要な記憶容量が大きくなる欠点はあるものの、露光量データが表す露光量ｅでのプリント理想特性を得るためのプリント理想特性の平行移動量が小さくなる確率が高いので、より精度の高いプリント理想特性が得られる確率が高くなる。
【００９０】
一方、ステップ１８６では、ステップ１７８で取込んだネガ画像データに基づいて、ネガ画像の画面平均濃度ｄ_AVを演算する。次のステップ１８８では、ネガ画像の画面平均濃度ｄ_AV及び前述したプリント理想特性に基づいて、プリント画像の画面平均濃度ＤＸ_AVを求める。このプリント画像の画面平均濃度ＤＸ_AVはプリント理想特性を用いて求めているので、プリンタプロセッサ１０が標準状態のときに、画面平均濃度ｄ_AVのネガ画像を、露光量データが表す露光量ｅで印画紙１６に露光し、プロセッサ部６４で現像等の処理を行ったときに印画紙１６に形成されると推定される理想プリント画像（本発明の標準複写画像に相当）の画面平均濃度（標準複写画像の画像特徴量）に相当しており、このステップ１８８の処理は、標準複写画像の推定、より詳しくは標準複写画像の画像特徴量の導出に対応している。
【００９１】
ステップ１９０では、ステップ１７６で取込んだプリント画像データに基づいて、プリント画像の画面平均濃度Ｄ_AV（複写画像の画像特徴量に相当）を演算し、ステップ１９２ではプリント画像の画面平均濃度Ｄ_AVと理想プリント画像の画面平均濃度ＤＸ_AVとの相違度ｚを、一例として次の（３）式に従って演算する。
【００９２】
ｚ＝ＤＸ_AV−Ｄ_AV …（３）
（３）式により求まる相違度ｚは、理想プリント画像の画面平均濃度ＤＸ_AVと実際のプリント画像の画面平均濃度Ｄ_AVとの差であり、理想プリント画像の画面平均濃度ＤＸ_AVはプリンタプロセッサ１０が標準状態のときのプリント画像の画面平均濃度の推定値であるので、相違度ｚの値が０以外であった場合には、プリンタプロセッサ１０の各種処理条件の何れかが標準状態での処理条件から偏倚していると判断できる。
【００９３】
このため、次のステップ１９４では、ステップ１９２で演算した相違度ｚの値に基づいて、露光量補正値ΔＥを演算する。本第１実施形態では、露光量補正値ΔＥとして露光時間補正値Δｔを用いており、一例として次の（４）式により露光時間補正値Δｔを求め、演算結果をＲＡＭ９４Ｃ等に記憶する。このステップ１９４は、露光処理のステップ１６０（図３参照）と共に本発明の補正手段に対応している。
【００９４】
Δｔ＝（ａ×ｚ）＋Δｔ₀ …（４）
但し、 ａ ：係数（ａ＞０）
Δｔ₀ ：現在設定されている露光時間補正値
上記により、実際のプリント画像の画面平均濃度Ｄ_AVが理想プリント画像の画面平均濃度ＤＸ_AVよりも高い場合には（ａ×ｚ）の項の符号が負となり、（２）式からも明らかなように、露光時間ｔが短くなりプリント濃度Ｄが低くなるように露光時間補正値Δｔが変更設定される。また、実際のプリント画像の画面平均濃度Ｄ_AVが理想プリント画像の画面平均濃度ＤＸ_AVよりも低い場合には（ａ×ｚ）の項の符号が正となり、露光時間ｔが長くなりプリント濃度Ｄが高くなるように露光時間補正値Δｔが変更設定される。
【００９５】
なお、係数ａの値は図５（Ａ）に示した露光量Ｅとプリント濃度Ｄとの関係の傾きを基準にして定めることができる。但し、露光量補正処理は繰り返し実行されるので、露光時間補正値Δｔも閉ループ制御により繰り返し更新される。従って、係数ａの値を比較的小さくした場合には露光時間補正値Δｔの変更量（ａ×ｚ）が小さくなるので、制御系としての安定度は高いが応答は遅くなり、係数ａの値を比較的大きくした場合には露光時間補正値Δｔの変更量（ａ×ｚ）が大きくなるので、応答は速くなるものの制御系としての安定度が低くなるという性質がある。このため、係数ａの最適値は実験的に求めることが好ましい。
【００９６】
次のステップ３００では、上述した処理を印画紙１６に形成されている全ての画像に対して行ったか否か判定する。判定が否定された場合にはステップ１７０に戻り、ステップ１７０〜３００を繰り返す。これにより、印画紙１６に記録されている各プリント画像に対し、各々露光量補正値ΔＥ（より詳しくは露光時間補正値Δｔ）が演算されてＲＡＭ９４Ｃ等に記憶されることになる。
【００９７】
ステップ３００の判定が肯定された場合にはステップ３０２へ移行し、各プリント画像に対して各々演算した露光量補正値ΔＥ（より詳しくは露光時間補正値Δｔ）の平均値を演算し、演算した平均値を実際の露光量補正値ΔＥ（より詳しくは露光時間補正値Δｔ）として設定し、処理を終了する。
【００９８】
これにより、次に露光処理が行われるときには、新たに設定した露光量補正値ΔＥによりステップ１６０（図３参照）で補正した露光量Ｅを用いて印画紙１６へのネガ画像の焼付露光が行われるので、プリンタプロセッサ１０の状態の変動に拘らずプリント画像の濃度が理想プリント画像の濃度に一致するように、ネガ画像の焼付露光が行われることになる。
【００９９】
なお、上記では露光処理においてネガ画像データを記憶手段９４Ｅに一旦記憶し、露光量補正処理においてネガ画像の画面平均濃度を演算するようにしていたが、これに限定されるものではなく、露光処理においてネガ画像の画面平均濃度を演算し、演算結果を記憶手段９４Ｅに記憶するようにしてもよい。
【０１００】
また、上記では画像特徴量として画面平均濃度を用いていたが、これに限定されるものではなく、濃度の最大値、最小値、中間値等の画像特徴量を用いて相違度ｚを演算するようにしてもよい。
【０１０１】
〔第２実施形態〕
次に本発明の第２実施形態について説明する。なお、本第２実施形態は第１実施形態と同一の構成であるので、各部分に同一の符号を付して構成の説明を省略し、以下では本第２実施形態の作用を説明する。
【０１０２】
本第２実施形態では、相違度ｚを演算するための濃度値の測定ポイントとして、互いに異なる複数のネガ濃度値がネガ濃度軸上で予め定められている（図７では例として４個の測定ポイントｐ１〜ｐ４を示す）。なお、測定ポイントは濃度が極端に高い又は極端に低い範囲を除外して定めることが好ましい。
【０１０３】
後述するように、本第２実施形態では前記各測定ポイントに対応する画素のプリント画像上における濃度値Ｄ及び理想プリント画像上における濃度値ＤＸを用いて相違度ｚを演算するが、濃度が極端に高い又は極端に低い範囲ではプリント理想特性の直線性が低下するので、この範囲では理想プリント画像の濃度値ＤＸの精度も低くなる。上記のように、濃度が極端に高い又は極端に低い範囲を除外して測定ポイントを定めれば、理想プリント画像の濃度値ＤＸとして精度の低いデータを用いずに相違度ｚを演算することになるので、相違度ｚとしてプリンタプロセッサ１０の各種処理条件の変動を正確に反映した値が得られる。
【０１０４】
次に本第２実施形態に係る露光量補正処理について、図６のフローチャートを参照して説明する。本第２実施形態に係る露光量補正処理では、第１実施形態で説明した露光量補正処理のステップ１８６〜１９４（図４参照）に代えて、ステップ２００〜２０８及びステップ２２０、２２２の処理を行う。なお、本第２実施形態では、第１実施形態で説明したステップ１７８〜１８４、及びステップ２００〜２０８が本発明の演算手段に対応している。
【０１０５】
ステップ２００では、ステップ１７８で取込んだネガ画像データに基づき、前記複数の測定ポイントに対応する濃度値の画素をネガ画像から選択する。次のステップ２０２ではプリント理想特性（図７に実線で示す）に基づいて、ネガ画像上における前記複数の測定ポイントの何れかに対応する濃度値の複数の画素の、理想プリント画像上における濃度値ＤＸ（標準複写画像の画像特徴量）を求める。これは、各測定ポイントに対応する複数のネガ濃度値を、プリント理想特定を用いてプリント濃度値に各々変換することにより実現できる。このステップ２０２の処理は標準複写画像の推定、より詳しくは標準複写画像の画像特徴量の導出に対応している。
【０１０６】
またステップ２０４では、ステップ２００で選択した画素に対応する画素のデータを、ステップ１７８で取り込んだプリント画像データから選択する。図７には、ステップ２０４でプリント画像データから選択した画素のデータが表す濃度値Ｄを、プリント理想特性を示す図表上にプロットした結果の一例を示す。このプロットした結果に基づき、実際のプリント画像におけるネガ濃度ｄとプリント濃度Ｄとの関係（現在のプリント特性）を直線で近似したとすると、プリンタプロセッサ１０の各種処理条件の少なくとも何れかが標準状態での処理条件から偏倚している場合には、図７に破線で示すように、理想プリント特性に対し現在のプリント特性が偏倚することになる。
【０１０７】
このためステップ２０６では、プリント理想特性に対する現在のプリント特性の偏差を相違度ｚとして演算する。具体的には次の（５）式に示すように((５）式では測定ポイントの数をｍとする）、ステップ２０２、２０４で導出又は選択したプリント画像における複数の濃度値Ｄ_j ((５）式におけるｊは測定ポイント毎に付した符号）及び理想プリント画像における複数の濃度値ＤＸ_j の差分を各測定ポイント毎に各々演算し、各測定ポイント毎の差分を各測定ポイント毎に定めた重み係数ｗ_j により重み付けして累積することにより相違度ｚを求める。
【０１０８】
【数１】

【０１０９】
なお、（５）式における重み係数ｗ_j は、例えば各測定ポイントに対応するネガ濃度ｄがネガ画像における主要部（例えば画像中の人物に相当する領域）の濃度である確率の高い値であるか否かに基づき、ネガ濃度ｄが主要部濃度である確率の高い測定ポイントの重みが大きくなるように定めることができる。この重み係数の設定は、より詳しくは請求項４に記載の演算手段に対応している。これにより、画像の主要部領域の画質に対しての影響の度合いが高い処理条件が変動した場合には、この変動が微小であっても相違度ｚの絶対値が大きくなり、主要部領域の画質が高い精度で一定となるように露光量が補正されることになる。
【０１１０】
次のステップ２０８では、上記で演算された相違度ｚの値に基づいて、第１実施形態で説明した露光量補正処理のステップ１９４と同様にして、露光量補正値ΔＥ（より詳しくは露光時間補正値Δｔ）を演算する。ステップ２２０では、ステップ１７８で取り込んだプリント画像データに基づいて、実際のプリント画像上で輝度値が最大の画素（Ｒ、Ｇ、Ｂの平均濃度が最小の画素）を判断し、該画素のデータをプリント画像データから取り込む。
【０１１１】
本第２実施形態では、露光量補正値ΔＥが、露光時間補正値Δｔと色バランス補正値ΔＣとから構成されている。次のステップ２２２では、ステップ２２０で取り込んだ画素の色相が白（Ｒ、Ｇ、Ｂの各濃度が一定）となるように、露光量補正値ΔＥの色バランス補正値ΔＣを設定する。このステップ２２０、２２２は、露光処理のステップ１６０（図３参照）と共に、請求項９に記載の補正手段に対応している。
【０１１２】
これにより、次に露光処理が行われるときには、ステップ１６０（図３参照）において、露光時間補正値Δｔ及び色バランス補正値ΔＣから成る新たに設定した露光量補正値ΔＥに基づいて、露光処理の露光時間補正値Δｔに基づく露光時間の補正に加え、色バランス補正値ΔＣに基づく色補正フィルタ２８の各フィルタの位置の補正も行われ、補正した露光量Ｅを用いて印画紙１６へのネガ画像の露光が行われるので、プリンタプロセッサ１０の状態の変動に拘らずプリント画像の濃度が理想プリント画像の濃度に一致し、かつプリント画像の輝度が最大の部分の色相が白となるようにネガ画像が印画紙１６に露光されることになる。
【０１１３】
〔第３実施形態〕
次に本発明の第３実施形態について説明する。なお、本第３実施形態は第１実施形態と同一の構成であるので、各部分に同一の符号を付して構成の説明を省略し、以下では本第３実施形態に係る露光量補正処理について、図８のフローチャートを参照して説明する。
【０１１４】
本第３実施形態に係る露光量補正処理では、第２実施形態で説明した露光量補正処理のステップ２００〜２０８（図６参照）に代えて、ステップ２１０〜２１６の処理を行う。本第３実施形態では、第１実施形態で説明したステップ１７８〜１８４及びステップ２１０〜２１６が本発明の演算手段に対応している。
【０１１５】
ステップ２１０では、ステップ１７８で取込んだネガ画像データが表すネガ画像の各画素毎の濃度及びプリント理想特性に基づいて、理想プリント画像の各画素毎の濃度を導出する。この理想プリント画像の各画素毎の濃度は、ネガ画像の各画素毎の濃度値を、プリント理想特性を用いてプリント濃度値に各々変換することにより得られる。以下では、上記処理によって得られた理想プリント画像の各画素毎の濃度（画素毎の画像特徴量）を表すデータ（本発明の標準複写画像データ）を理想プリント画像データと称する。
【０１１６】
次のステップ２１２では、ネガ画像上で濃度値が所定範囲内に収まっている画素のデータを、理想プリント画像データ及びステップ１７６で取込んだプリント画像データから各々取り出す。なお、上記に代えて、プリント画像データ及び理想プリント画像データの何れか一方から濃度値が所定範囲内に収まっている画素のデータを取り出すと共に、前記データを取り出した画素に対応する画素のデータを他方の画像データから取り出すようにしてもよいし、プリント画像上での濃度値及び理想プリント画像上での濃度値が各々所定範囲内に収まっている画素のデータをプリント画像データ及び理想プリント画像データから各々取り出すようにしてもよい。
【０１１７】
上述した画素のデータの取り出しは、請求項５に記載の「所定の基準に従って複数画素を選択」することに対応している。例えばプリンタプロセッサ１０の各種処理条件の少なくとも何れかが標準状態での処理条件から偏倚している場合には、上記のようにしてプリント画像データ及び理想プリント画像データから取り出したデータが表す濃度値は、理想プリント画像と実際のプリント画像とで異なることになり、プリント画像データ及び理想プリント画像データから取り出したデータを各々プリント理想特性を示す図表上にプロットしたとすると、理想プリント画像データから取り出したデータは、図７に実線で示す理想プリント特性を表す直線上にプロットされるのに対し、プリント画像データから取り出したデータは、例えば図７に破線で示す現在のプリント特性を表す直線上又はその付近にプロットされる。
【０１１８】
ステップ２１４では次の（６）式に従い、相違度ｚとして、プリント画像データから取り出したデータが表す濃度値Ｄ_j ((６）式におけるｊは取り出した画素のデータに各々付した符号）と、理想プリント画像データから取り出したデータが表す濃度値ＤＸ_j と、の各画素毎の差分の平均値を演算する。
【０１１９】
【数２】

【０１２０】
但し、ｎ：取り出した画素のデータの総数
なお、濃度値の差分の平均値に代えて、相違度ｚとして濃度値の差分の累積値を演算するようにしてもよい。この（６）式による相違度ｚの演算は、請求項５に記載の演算手段に対応している。そして、次のステップ２１６では、上記で演算した相違度ｚの値に基づいて、露光量補正値ΔＥ（露光時間補正値Δｔ）を演算する。なお、次のステップ２２０以降の処理は第２実施形態と同じである。
【０１２１】
これにより、次に露光処理が行われるときには、新たに設定した露光量補正値ΔＥに基づいて露光時間及び色補正フィルタ２８の各フィルタの位置の補正も行われ、補正した露光量Ｅを用いて印画紙１６へのネガ画像の露光が行われるので、第２実施形態と同様に、プリンタプロセッサ１０の状態の変動に拘らずプリント画像の濃度が理想プリント画像の濃度に一致し、かつプリント画像の輝度が最大の部分の色相が白となるように、ネガ画像が印画紙１６に露光される。
【０１２２】
なお、上記では相違度ｚとして、プリント画像データ及び理想プリント画像データから取り出した画素の濃度値の差分の平均値（又は累積値）を演算する例を説明したが、これに限定されるものではなく、相違度ｚとして、濃度値の差分を画素毎に重み付けした結果の平均値又は累積値を演算するようにしてもよい。画素毎の重み係数の設定は例えば以下のようにして行うことができる。
【０１２３】
（１）各画素の濃度値に基づく重み係数の設定
プリント画像データ及び理想プリント画像データにおいて画素がとりうる濃度値の全範囲（例えば画素の濃度を８ビットのデータで表すとすると、濃度値＝０〜２５５の範囲）を、図９に示すように、所定の濃度差の範囲毎に複数の濃度範囲（図９では一例として濃度範囲１〜濃度範囲ｒのｒ個の濃度範囲）に分割し、各濃度範囲毎に重み係数ｗを予め定めておく。この重み係数は、例えば画像中の人物に相当する領域の平均的な濃度値に対応する濃度範囲の重みが大きくなり、濃度が極端に高い又は極端に低い濃度範囲の重みが小さくなるように定めることができる。そして、プリント画像データ（又は理想プリント画像データ）の各画素の濃度が何れの濃度範囲に属するかを各々判断し、各画素が属している濃度範囲に対して定めた重み係数ｗを各画素の重み係数として設定する。
【０１２４】
（２）各画素の色相に基づく重み係数の設定
所定の色座標によって定義される色空間を複数の色領域に分割し（一例として図１０には、Ｒ−Ｇを横軸に、Ｇ−Ｂを縦軸にとった色座標によって定義される色空間を、縦軸又は横軸に平行な線分によって色領域ａ〜ｐの１６個の色領域に分割した例を示す）、各色領域毎に重み係数を予め定めておく。この重み係数は、例えば画像中の人物に相当する領域の平均的な色相に対応する色領域の重みが大きくなり、画像中の背景部に相当する領域に多く存在する色相（例えば海や空の青、芝生の緑等）に対応する色領域の重みが小さくなるように定めることができる。そして、プリント画像データ（又は理想プリント画像データ）の各画素の色相が何れの色領域に属するかを各々判断し、各画素が属している色領域に対して定めた重み係数ｗを各画素の重み係数として設定する。
【０１２５】
（３）クラスタ分析による重み係数の設定
プリント画像データ（又は理想プリント画像データ）に基づき、濃度ヒストグラム、或いは色相値（及び彩度値）についてのヒストグラムを求め、求めたヒストグラムを山毎に各々分割し、各画素が分割した山の何れに属するかを判断して各画素を分割した山に対応する群に分ける（クラスタ分析）。次に、各群の特性（例えば各群に属する画素数、各群に対応する山のピークにおける度数、所定の色空間（例えば色相値及び彩度値を縦軸及び横軸にとった色座標によって定義される色空間）上での所定の基準値からの各群の距離等）に応じて、画像中の主要部に相当すると推定される群の重みが大きくなるように各群毎に重み係数を定める。そして、プリント画像データ（又は理想プリント画像データ）の各画素が何れの群に属するかに基づいて、各画素に重み係数を設定する。
【０１２６】
上述した重み係数の設定は、画像中の主要部に関連すると推定される画素の重みが大きくなるように行っており、より詳しくは請求項４に記載の演算手段に対応している。上記のようにして各画素に対して重み係数を設定した場合には、前述の（５）式又は次の（７）式（但し、この場合のｊは相違度ｚの演算対象の画素のデータに各々付した符号）により相違度ｚを演算することができる。
【０１２７】
【数３】

【０１２８】
但し、ｎは相違度ｚ演算対象の画素の総数
なお、上記の（１）〜（３）において、濃度が極端に高い、又は極端に低い画素や、彩度が高い画素のデータについては相違度ｚの演算に用いないようにしてもよいことは言うまでもない。
【０１２９】
上記のように、画像中の主要部に関連すると推定される画素の濃度の比較結果（ＤＸ_j −Ｄ_j ）の重みが大きくなるように重み付けを行っているので、画像の主要部に相当する領域の画質に対しての影響の度合いが高い処理条件が変動したとすると、この変動が微小であっても相違度ｚが大きくなり、画像中の主要部に相当する領域の画質が向上するように露光量Ｅが補正されることになるので、プリント画像のうち特に画質の評価で注目される主要部領域の画質を高い精度で一定とすることができる。
【０１３０】
〔第４実施形態〕
次に本発明の第４実施形態について説明する。なお、本第４実施形態は第１実施形態と同一の構成であるので、各部分に同一の符号を付して構成の説明を省略し、以下では本第４実施形態に係る露光量補正処理について、図１１のフローチャートを参照して説明する。
【０１３１】
本第４実施形態に係る露光量補正処理では、第１実施形態で説明した露光量補正処理のステップ１８６〜１９４（図４参照）に代えて、ステップ２３０〜２３６の処理を行う。本第４実施形態では、第１実施形態で説明したステップ１７８〜１８４及びステップ２３０〜２３４が本発明の演算手段に対応している。ステップ２３０では、ステップ１７８で取込んだネガ画像データが表すネガ画像の各画素毎の濃度及びプリント理想特性に基づいて、第３実施形態で説明した露光量補正処理のステップ２１０（図８参照）と同様にして、理想プリント画像の各画素毎の濃度を導出することにより、理想プリント画像データを生成する。
【０１３２】
ステップ２３２では、上記で生成した理想プリント画像データ及びステップ１７６で取り込んだプリント画像データに基づいて、理想プリント画像及び実際のプリント画像の濃度ヒストグラムを各々作成し、次のステップ２３４では、理想プリント画像の濃度ヒストグラム及び実際のプリント画像の濃度ヒストグラムに基づいて、理想プリント画像と実際のプリント画像との相違度ｚを演算する。
【０１３３】
この相違度ｚの演算は、例えば理想プリント画像の濃度ヒストグラムの形状と実際のプリント画像の濃度ヒストグラムの形状とを比較し、形状の相違度を相違度ｚとして設定することができる。
【０１３４】
具体的には、双方のヒストグラムにおける各濃度階級毎の度数の差分の絶対値をヒストグラム全体又は所定の濃度範囲内に亘って累積した値（以下、ヒストグラム相違度と称する）を基準とし、一方のヒストグラムを度数軸に平行に全体的に移動させたときに、平行移動させたヒストグラムと他方のヒストグラムとのヒストグラム相違度が最小となるヒストグラムの平行移動量を求め、このヒストグラム相違度が最小のときのヒストグラムの平行移動量を相違度ｚとして設定すればよい。また、所定の条件に従って一部をヒストグラムから除外して（例えば濃度の最大値又は最小値からの累積度数が所定値に達するまでの濃度範囲を除外する等）、上述したヒストグラムの形状の比較を行うようにしてもよい。
【０１３５】
また、双方のヒストグラムにおいて対応している箇所の画素データが表す画像特徴量（例えば濃度値）を比較して、濃度値の相違度を相違度ｚとして設定するようにしてもよい。具体的には、双方のヒストグラムにおいて、度数が最大又は最小となっている箇所、度数のピーク（極大又は極小）が生じている箇所、濃度の最大値又は最小値からの累積度数が所定値に達する箇所に相当する画素データが表す画像特徴量（例えば濃度値）の差分の累積値又は平均値を求め、これを相違度ｚとして設定することにより実現できる。上述したヒストグラムによる相違度ｚの演算は、より詳しくは請求項６に記載の演算手段に対応している。
【０１３６】
上記のように、ヒストグラムを用いて相違度ｚを演算する場合にも、相違度ｚの値に悪影響を及ぼすデータ（例えば濃度が極端に高い又は極端に低い画素のデータ等）を除去して相違度ｚを演算することができるので、相違度ｚとして、プリンタプロセッサ１０の各種処理条件の変動を正確に反映した値が得られる。なお相違度ｚは、例えば相違度ｚの演算に用いる画素のＲ、Ｇ、Ｂの各成分色毎の画像特徴量等に基づいて、各成分色毎に演算するようにしてもよい。
【０１３７】
そして、次のステップ２３６では、ステップ２３４で演算した相違度ｚの値に基づいて露光量補正値ΔＥを演算する。これにより、次に露光処理が行われるときには、新たに設定した露光量補正値ΔＥによりステップ１６０（図３参照）で補正した露光量Ｅを用いて印画紙１６へのネガ画像の焼付露光が行われるので、プリンタプロセッサ１０の状態の変動に拘らずプリント画像の濃度が理想プリント画像の濃度に一致するように、ネガ画像の焼付露光が行われることになる。
【０１３８】
なお、ステップ２３４で相違度ｚを各成分色毎に演算した場合には、ステップ２３６で露光量補正値ΔＥとして、各成分色毎の相違度ｚを用いて色バランス補正値ΔＣを設定することができる。この場合、色バランス補正値ΔＣに基づく色補正フィルタ２８の各フィルタの位置の補正も行われて印画紙１６へのネガ画像の露光が行われるので、プリンタプロセッサ１０の状態の変動に拘らず、プリント画像の濃度及び色バランスが理想プリント画像の濃度及び色バランスに一致するように、ネガ画像の焼付露光が行われることになる。
【０１３９】
〔第５実施形態〕
次に本発明の第５実施形態について説明する。なお、本第５実施形態についても第１実施形態と同一の構成であるので、各部分に同一の符号を付して構成の説明を省略し、以下では本第５実施形態に係る露光量補正処理について、図１２のフローチャートを参照して説明する。
【０１４０】
本第５実施形態に係る露光量補正処理では、第１実施形態で説明した露光量補正処理のステップ１８６〜１９４（図４参照）に代えて、ステップ２４０〜２４６の処理を行う。本第５実施形態では、第１実施形態で説明したステップ１７８〜１８４及びステップ２４０〜２４６が本発明の演算手段に対応している。
【０１４１】
ステップ２４０では、ステップ１７８で取込んだネガ画像データが表すネガ画像の各画素毎の濃度及びプリント理想特性に基づいて、第３実施形態で説明した露光量補正処理のステップ２１０（図８参照）、第４実施形態で説明した露光量補正処理のステップ２３０（図１１参照）と同様にして、理想プリント画像の各画素毎の濃度を導出することにより、理想プリント画像データを生成する。
【０１４２】
ステップ２４２では理想プリント画像及び実際のプリント画像を所定の基準により複数領域に各々分割し、各領域に対して各々重み係数を設定する。この画像の分割は、例えば以下に列挙する方法の何れかを適用して行うことができる。
【０１４３】
（１）人物領域抽出による画像分割・重み係数の設定
人物写真において鑑賞時に最も注目される部位は人物（特に人物の顔）に相当する部分であるので、画像中の主要部として人物に相当する領域を抽出し、抽出した人物に相当する領域の重みが、それ以外の領域の重みよりも大きくなるように、各領域に重み係数を設定する。画像からの人物に相当する領域の抽出は、プリント画像及び理想プリント画像に対して各々行ってもよいが、プリント画像及び理想プリント画像の一方に対してのみ人物に相当する領域の抽出・画像分割を行い、前記一方の画像を複数領域に分割した結果に基づいて他方の画像を複数領域に分割するようにした方が、人物に相当する領域を抽出する処理を実行する回数が少なくて済むので好ましい。プリント画像又は理想プリント画像からの人物に相当する領域の抽出は、例えば以下のようにして行うことができる。
【０１４４】
〔人物領域抽出方式の例１〕
プリント画像データ（又は理想プリント画像データ）に基づいて、プリント画像（又は理想プリント画像）を構成する各画素のデータが色座標上で肌色の範囲内に含まれているか否かを各々判定し、肌色の範囲内と判断した画素のクラスタ（群）が存在している領域を、人物に相当する領域としてプリント画像（又は理想プリント画像）から抽出する（特開昭 52-156624号公報、特開昭 52-156625号公報、特開昭53-12330号公報、特開昭 53-145620号公報、特開昭 53-145621号公報、特開昭 53-145622号公報等参照）。
【０１４５】
〔人物領域抽出方式の例２〕
プリント画像データ（又は理想プリント画像データ）に基づき、濃度ヒストグラム、或いは色相値（及び彩度値）についてのヒストグラムを求め、求めたヒストグラムを山毎に各々分割し、各画素が分割した山の何れに属するかを判断して各画素を分割した山に対応する群に分け（クラスタ分析）、プリント画像（又は理想プリント画像）を各群毎に複数の領域に分割し、該複数の領域のうち人物の顔に相当する領域を推定し、推定した領域をプリント画像（又は理想プリント画像）から抽出する（特開平4-346332号公報参照）。
【０１４６】
〔人物領域抽出方式の例３〕
プリント画像データ（又は理想プリント画像データ）に基づき、プリント画像中（又は理想プリント画像中）に存在する人物の各部に特有の形状パターン（例えば頭部の輪郭、顔の輪郭、顔の内部構造、胴体の輪郭等を表す形状パターン）の何れか１つを各々探索し、検出した形状パターンの大きさ、向き、検出した形状パターンが表す人物の所定部分と人物の顔との位置関係に応じて、人物の顔に相当すると推定される領域を設定する。また、検出した形状パターンと異なる他の形状パターンを探索し、先に設定した領域の、人物の顔としての整合性を求め、人物の顔に相当する領域として抽出する（特願平6-265850号、特願平6-266598号）。
【０１４７】
（２）背景領域抽出による画像分割・重み係数の設定
画像中の非主要部として背景に相当する領域を抽出し、抽出した背景に相当する領域の重みが、それ以外の領域の重みよりも小さくなるように（背景に相当する領域以外の領域に画像の主要部に相当する領域が存在していると判断する）、各領域に重み係数を設定する。画像からの背景に相当する領域の抽出についても、プリント画像及び理想プリント画像に対して各々行ってもよいが、プリント画像及び理想プリント画像の一方に対してのみ背景に相当する領域の抽出・画像分割を行い、前記一方の画像を複数領域に分割した結果に基づいて他方の画像を複数領域に分割するようにした方が、背景に相当する領域を抽出する処理を実行する回数が少なくて済むので好ましい。プリント画像又は理想プリント画像からの背景に相当する領域の抽出は、例えば以下のようにして行うことができる。
【０１４８】
〔背景領域抽出方式の例１〕
プリント画像データ（又は理想プリント画像データ）に基づいて、各画素が、色座標上で明らかに背景に属する特定の色（例えば空や海の青、芝生の緑等）の範囲内に含まれているか否か判定し、前記特定の色範囲内と判断した画素のクラスタ（群）が存在している領域を背景に相当する領域と判断して抽出する。
【０１４９】
〔背景領域抽出方式の例２〕
プリント画像データ（又は理想プリント画像データ）に基づいて、先の人物領域抽出方式の例２と同様にしてプリント画像（又は理想プリント画像）を複数の領域に分割した後に、各領域毎に背景に相当する領域としての特徴量（輪郭に含まれる直線部分の比率、線対称度、凹凸数、画像外縁との接触率、領域内の濃度コントラスト、領域内の濃度の変化パターンの有無等）を求め、求めた特徴量に基づいて各領域が背景に相当する領域か否か判定し背景に相当する領域を抽出する（特願平6-265850号、特願平6-266598号）。
【０１５０】
（３）クラスタ分析による画像分割・重み係数の設定
このクラスタ分析による画像分割についても、プリント画像及び理想プリント画像に対して各々行ってもよいが、プリント画像及び理想プリント画像の一方に対してのみクラスタ分析による画像分割を行い、前記一方の画像を複数領域に分割した結果に基づいて他方の画像を複数領域に分割するようにした方が、クラスタ分析処理を実行する回数が少なくて済むので好ましい。クラスタ分析による画像分割は、プリント画像データ（又は理想プリント画像データ）に基づいて、先の人物領域抽出方式の例２と同様にして画像を複数の領域に分割した後に、人物の顔に相当する領域を推定することなく、各領域の特性（例えば各領域の面積、各領域内のコントラスト、画面上の所定の基準位置（例えば画面中央等）からの各領域の距離等）に応じて各領域毎に重み係数を設定する。
【０１５１】
（４）固定パターンによる画像分割・重み係数の設定
例として図１３に示すように、画像を固定的に分割する分割パターン（図１３では画像を領域ａ〜領域ｅの５個の領域に分割する分割パターンを示す）を予め定めておくと共に、該分割パターンによって分割される各領域毎に予め重み係数を定めておく。なお重み係数は、例えば画像の主要部は画面中央付近に位置している確率が高いとの経験則に基づいて、画面中央付近に位置している領域（図１３では領域ａ）の重み係数が高くなるように定めることができる。そして、該分割パターンに従ってプリント画像及び理想プリント画像を各々分割する。
【０１５２】
なお、画像を複数領域に分割する方法は、上記に限定されるものではなく、例えば濃度値の微分等により画像中のエッジ（輪郭線）を検出し、検出した輪郭線に基づいて画像を複数の領域に分割するようにしてもよい。上述した各方式による重み係数の設定は、画像中の主要部に関連すると推定される領域の重みが大きくなるように行っており、より詳しくは請求項４に記載の演算手段に対応している。
【０１５３】
上記のようにして画像分割及び重み係数の設定を行うと、次のステップ２４４ではプリント画像及び理想プリント画像の各領域について、画像特徴量を各々演算する。この画像特徴量としては、例えば各領域毎の平均濃度、濃度の最大値や最小値、濃度の中間値、各領域毎の濃度ヒストグラムのピークにおける濃度値、各領域毎の濃度ヒストグラムにおける濃度の最大値又は最小値からの累積度数が所定値のときの濃度値等を適用することができる。
【０１５４】
次のステップ２４６では、上記でプリント画像及び理想プリント画像の各領域について求めた画像特徴量を、ステップ２４２で各領域に対して設定した重み係数により重み付けし、該重み付けした値を用いて相違度ｚを演算する。この場合の相違度ｚは、例えば以下の（８）式又は（９）式に従って演算することができる。
【０１５５】
【数４】

【０１５６】
但し、ｓは領域数、ＴＸ_j は理想プリント画像の領域ｊの画像特徴量、Ｔ_j はプリント画像の領域ｊの画像特徴量、ｗ_j は領域ｊの重み係数である。上述した画像の分割、相違度の演算は請求項７に記載の演算手段に対応している。なお相違度ｚは、各領域のＲ、Ｇ、Ｂの各成分色毎の画像特徴量を用いて各成分色毎に演算するようにしてもよい。
【０１５７】
そして、次のステップ２４８では、ステップ２４６で演算した相違度ｚの値に基づいて露光量補正値ΔＥを演算する。これにより、次に露光処理が行われるときには、新たに設定した露光量補正値ΔＥに基づいて露光量Ｅが補正され、補正した露光量Ｅを用いて印画紙１６へのネガ画像の露光が行われるので、プリンタプロセッサ１０の状態の変動に拘らずプリント画像の濃度が理想プリント画像の濃度に一致するように、ネガ画像が印画紙１６に露光される。
【０１５８】
また上記では、画像中の主要部に関連すると推定される領域の画像特徴量の比較結果（ＴＸ_j −Ｔ_j ）の重みが大きくなるように重み付けを行っているので、画像の主要部に相当する領域の画質に対しての影響の度合いが高い処理条件の変動すると、この変動が微小であっても相違度ｚが大きくなり、画像中の主要部に相当する領域の画質が向上するように露光量Ｅが補正されることになるので、プリント画像のうち特に画質の評価で注目される主要部領域の画質を高い精度で一定とすることができる。
【０１５９】
なお、ステップ２４６で相違度ｚを各成分色毎に演算した場合には、ステップ２４８で露光量補正値ΔＥとして、各成分色毎の相違度ｚを用いて色バランス補正値ΔＣを設定することができる。この場合、色バランス補正値ΔＣに基づく色補正フィルタ２８の各フィルタの位置の補正も行われて印画紙１６へのネガ画像の露光が行われるので、プリンタプロセッサ１０の状態の変動に拘らず、プリント画像の濃度及び色バランスが理想プリント画像の濃度及び色バランスに一致するように、ネガ画像の焼付露光が行われることになる。
【０１６０】
〔第６実施形態〕
次に本発明の第６実施形態について説明する。なお、本第６実施形態は第１実施形態と同一の構成であるので、各部分に同一の符号を付して構成の説明を省略し、以下では本第６実施形態に係る理想プリント画像推定処理について、図１４のフローチャートを参照して説明する。
【０１６１】
この理想プリント画像推定処理は、上述した各実施形態における露光量補正処理と同様に、露光処理によって画像が露光記録された印画紙１６の先端部が乾燥部７２から排出されると実行される。この理想プリント画像推定処理では、図１４からも明らかなように、本第３実施形態で説明した露光量補正処理（図８参照）のステップ１７０〜２１０を行った後に、ステップ３００の判定を行い、ステップ３００の判定が肯定される迄ステップ１７０〜２１０を繰り返す。
【０１６２】
但し理想プリント画像推定処理では、ステップ１７６において、取り込んだプリント画像データを記憶手段９４Ｅ等に記憶すると共に、ステップ２１０において、理想プリント画像データを求めた後に該理想プリント画像データを記憶手段９４Ｅ等に記憶する。これにより、印画紙１６への露光が行われた全画像について、プリント画像データ及び理想プリント画像データが各々記憶されることになる。この理想プリント画像推定処理のステップ１７８〜２１０は、請求項１０に記載の推定手段に対応している。
【０１６３】
次に図１５のフローチャートを参照し、本第６実施形態に係る画像表示・露光量補正処理について説明する。本第６実施形態では、オペレータがプリント画像の仕上りの検定や、プリンタプロセッサ１０の状態のチェック等を行いたい場合、オペレータによりディスプレイ１００への画像の表示がキーボード２４等を介して指示される。画像表示・露光量補正処理は、オペレータによりディスプレイ１００への画像の表示が指示されると、割込みがかかって制御部９４のＣＰＵ９４Ａで実行される。
【０１６４】
ステップ４００では、オペレータに対しディスプレイ１００に表示すべき画像を指定する情報の入力を要請するメッセージをディスプレイに表示した後に、オペレータにより表示すべきプリント画像を指定する情報が入力されたか否か判定し、判定が肯定される迄待機する。オペレータが、表示すべきプリント画像を特定するための情報（例えばコマ番号等）を入力したり、或いは印画紙に露光された全てのプリント画像を表示させるために全画像表示を意味する情報を入力することにより表示すべき画像が指定されるとステップ４００の判定が肯定され、ステップ４０２へ移行する。
【０１６５】
ステップ４０２では、オペレータによって指定された画像のプリント画像データ、理想プリント画像データ及び露光量データを記憶手段９４Ｅ等から取込み、ステップ４０４では取り込んだデータに基づいて、指定された画像のプリント画像及び理想プリント画像をディスプレイ１００に同時に表示する。このステップ４０２は請求項１０の表示手段に対応している。次のステップ４０６では、オペレータに対しディスプレイ１００に表示している画像についての検定結果の入力を要請するメッセージをディスプレイ１００に表示した後に、オペレータにより検定結果が入力されたか否か判定し、判定が肯定される迄待機する。
【０１６６】
一方、指定した画像のプリント画像及び理想プリント画像がディスプレイ１００に同時に表示されると、オペレータは、表示されたプリント画像及び理想プリント画像を参照・比較（複数の画像コマのプリント画像及び理想プリント画像が表示されている場合には、各画像コマのプリント画像及び理想プリント画像を各々参照・比較）することにより、プリンタプロセッサ１０が標準状態から偏倚していないか否か検定する。そして、プリンタプロセッサ１０の各種処理条件の何れかが標準状態での処理条件から偏倚していると判断した場合には、検定結果として、露光量の補正を行うことを表す情報を入力すると共に、露光量に対する補正値を入力する。
【０１６７】
またオペレータは、ディスプレイ１００に表示されているプリント画像を参照（複数の画像コマのプリント画像及び理想プリント画像が表示されている場合には、各画像コマのプリント画像を１コマずつ参照）することにより、指定した画像のプリント結果が適正か否かの検定（例えばプリント画像の各部分の濃度、色等が適正か否かの判定等）を行う。そして、プリント結果も適正であると判断した場合には、検定結果が「全てＯＫ」であることを表す情報を入力するが、プリント結果が適正でない画像が有った場合には、検定結果として再プリントを行うことを表す情報を入力すると共に、再プリントを行う画像の露光量に対する補正値を入力する。
【０１６８】
上記のようにしてオペレータから何らかの情報が入力されると、ステップ４０６の判定が肯定されてステップ４０８へ移行する。ステップ４０８では、オペレータによる検定結果を判定しており、検定結果が「全てＯＫ」であった場合には処理を終了するが、検定結果が「露光量の補正」であった場合にはステップ４１０へ移行する。
【０１６９】
ステップ４１０では、現在ディスプレイ１００に表示している全ての画像について、ステップ４０２で取り込んだプリント画像データと検定結果と共に入力された露光量に対する補正値とに基づいて、入力された補正値により露光量を補正したときのプリント画像を表すシミュレーション画像を生成し、次のステップ４１２では生成したシミュレーション画像及び理想プリント画像をディスプレイ１００に同時に表示する。ステップ４１４では検定結果の入力を要請するメッセージを表示した後に、オペレータから検定結果が入力されたか否か判定する。
【０１７０】
一方、オペレータは、表示されたシミュレーション画像と理想プリント画像とを比較・参照し、双方の画像の各部分の濃度、色等が一致又は略一致したか否かに基づいて、先に入力した露光量の補正値が適正か否か判定する。そして、適正でなければ露光量の補正値を再度入力し、適正であれば検定結果が「ＯＫ」であることを表す情報を入力する。
【０１７１】
次のステップ４１６ではオペレータによる検定結果を判定しており、露光量の補正値が再度入力された場合にはステップ４１０へ戻り、ステップ４１０〜４１６を繰り返す。また、検定結果が「ＯＫ」であることを表す情報が入力された場合にはステップ４１８へ移行し、最終的に入力された露光量の補正値を、実際に露光量演算にフィードバックする露光量補正値ΔＥとして設定する。
【０１７２】
上記により、プリントプロセッサ１０の各種処理条件の何れかが標準状態での処理条件から偏倚しているとオペレータが判断した場合には、この処理条件の偏倚に伴うプリント画像の画質の変化が補正されるように露光量補正値ΔＥが設定されることになる。このステップ４１８及び露光時に露光量補正値ΔＥに基づいて露光量Ｅを補正する処理（図３のステップ１６０）は請求項１０に記載の補正手段に対応している。
【０１７３】
次のステップ４３０では、上記の露光量の補正により検定結果は「全てＯＫ」となったかをオペレータに確認するメッセージをディスプレイ１００に表示し、オペレータが「全てＯＫ」と判断しているか否か判定する。判定が肯定された場合には処理を終了するが、判定が否定された場合（例えば再プリントすべき画像コマが有るとオペレータが判断している場合）にはステップ４０６へ戻り、検定結果の入力を再度要請する。
【０１７４】
またステップ４０８において、検定結果が「再プリント」であった場合にはステップ４２０へ移行する。ステップ４２０では、再プリントを行う画像として指定された画像について、ステップ４０２で取り込んだプリント画像データと検定結果と共に入力された露光量に対する補正値とに基づいて（先のステップ４１８で露光量補正値ΔＥが設定された場合には、この補正値も加味して）、入力された補正値により露光量を補正したときのプリント画像を表すシミュレーション画像を生成し、次のステップ４２２では生成したシミュレーション画像（及び理想プリント画像）をディスプレイ１００に同時に表示する。
【０１７５】
ステップ４２４では検定結果の入力を要請するメッセージを表示した後に、オペレータから検定結果が入力されたか否か判定する。一方、オペレータは、表示されたシミュレーション画像を参照し、表示されたシミュレーション画像の各部分の濃度、色等が適正か否か基づいて、先に入力した露光量の補正値が適正か否か判定する。そして、適正でなければ露光量の補正値を再度入力し、適正であれば検定結果が「ＯＫ」であることを表す情報を入力する。
【０１７６】
次のステップ４２６ではオペレータによる検定結果を判定しており、露光量の補正値が再度入力された場合にはステップ４１０へ戻り、ステップ４２０〜４２６を繰り返す。また、検定結果が「ＯＫ」であることを表す情報が入力された場合にはステップ４２８へ移行し、最終的に入力された露光量の補正値を、再プリントを行う際に実際に露光量演算にフィードバックする露光量補正値として設定・記憶すると共に、再プリントを行う画像を識別するための情報（例えばコマ番号等）を記憶し、ステップ４３０へ移行する。
【０１７７】
このように、本第６実施形態ではオペレータより指定された画像のプリント画像及び理想プリント画像をディスプレイ１００に同時に表示するので、オペレータは、例えば実際のプリントを手に取って検定する等の煩雑な作業を行うことなく、ディスプレイ１００に表示されたプリント画像を参照することにより、指定した画像のプリント結果が適正か否かの検定を行うことができると共に、表示されたプリント画像及び理想プリント画像を参照・比較することにより、プリンタプロセッサ１０が標準状態か否かの検定を容易に行うことができる。
【０１７８】
また、ディスプレイ１００に表示された画像を参照することで検定を行うことができるので、例えばプリンタプロセッサ１０等の写真処理装置が複数台設置された現像所等において、各写真処理装置のプリント結果等を表示するディスプレイ（１台でも複数台でも良い）を所定箇所（例えば写真処理装置が設置されている箇所から離れている箇所等）に配設し、各写真処理装置の処理条件の管理、プリント結果の検定を前記所定箇所で集中的に行うことも可能である。
【０１７９】
なお、上記実施形態では、ネガ画像を読み取る第１の読取手段としてＣＣＤイメージセンサ８６を、プリント画像を読み取る第２の読取手段としてＣＣＤイメージスキャナ７６を各々設けた例を説明したが、単一の画像読取センサによってネガ画像及びプリント画像を各々読み取る構成としてもよい。例として、図１６にはＣＣＤイメージセンサ８６（請求項８に記載の画像読取素子に相当）によってネガ画像及びプリント画像を読み取るようにした構成が示されている。
【０１８０】
図１６の構成では、光源１１４から射出され印画紙１６で反射された光が一端側に入射されるように配置された、多数本の光ファイバから成る光ファイバアレイ１１６（案内手段）が設けられており、ＣＣＤイメージセンサ８６の光入射側には、図１６に実線で示す位置又は破線で示す位置に移動されるミラー１１８が設けられている。光ファイバアレイ１１６の他端側はミラー１１８の配設位置付近まで延設されている。
【０１８１】
ミラー１１８が実線で示す位置に位置している状態では、分配用プリズム３２で分配された光（ネガ画像を透過した光）がＣＣＤイメージセンサ８６に入射され、ＣＣＤイメージセンサ８６によってネガ画像が読み取られる。また、ミラー１１８が破線で示す位置に位置している状態では、光源１１４から射出され印画紙１６のプリント画像で反射された光が光ファイバアレイ１１６によってミラー１１８の配設位置に案内され、ミラー１１８で反射されてＣＣＤイメージセンサ８６に入射されることにより、ＣＣＤイメージセンサ８６によってプリント画像が読み取られる。
【０１８２】
上記のように、単一の画像読取センサ（上記ではＣＣＤイメージセンサ８６）を第１の読取手段及び第２の読取手段が共有する構成とすれば、読取手段に要するコストを低減することができる。なお、光ファイバアレイ１１６に代えて、ミラー等により光を案内するようにしてもよい。
【０１８３】
また、上記では印画紙１６がＣＣＤイメージスキャナ７６の配設位置に到達すると実行される露光量補正処理において、理想プリント画像の画像特徴量の演算を行っていたが、これに限定されるものではなく、露光処理（図３）において、又は印画紙１６がプロセッサ部６４で処理されている間に、理想プリント画像の画像特徴量の演算を行って演算結果を記憶しておくようにしてもよい。
【０１８４】
更に、ネガ画像を測光するＣＣＤイメージセンサ８６（第１の読取手段）と、プリント画像を測光するＣＣＤイメージスキャナ７６（第２の読取手段）とが各々測光対象画像を各々同数の画素に分割して測光する（すなわち解像度が同一）構成を説明したが、第１の読取手段と第２の読取手段の解像度は異なっていてもよい。この場合、画像特徴量として画面平均濃度を用いるのであれば、第１の読取手段からのネガ画像データ及び第２の読取手段からのプリント画像データを、画面平均濃度の演算にそのまま用いることができるが、画像特徴量として第２実施形態以降で説明した各種の画像特徴量の何れかを用いる場合には、ネガ画像データ及びプリント画像データの何れかに対して解像度変換等の処理を行うことにより、ネガ画像データを構成する画素数とプリント画像データを構成する画素数とを一致させた後に前記画像特徴量の演算を行うようにすればよい。
【０１８５】
また、第１の読取手段及び第２の読取手段として、ＣＣＤラインセンサ、ＭＯＳ型センサ等の他の画像読取センサを適用することも可能である。また画像読取素子は、画像を各成分色毎に分解して読み取るものに限定されるものではなく、画像の各部のグレーレベルを読み取る構成の素子を適用することも可能である。この場合、相違度ｚ及び露光量補正値ΔＥは各色の平均的な値を演算し、演算した露光量補正値ΔＥに基づいて各色毎の露光量を一様に補正すればよい。本発明はこのような実施形態も含むものである。
【０１８６】
また、上記では標準状態となるように調整されたプリンタプロセッサ１０により所定露光量ｅ_T でネガ画像を露光したときのネガ濃度ｄとプリント濃度Ｄとの関係（プリント理想特性）を記憶しておき、このプリント理想特性を、実際にネガ画像の露光を行った際の露光量Ｅに応じて平行移動させることにより、露光量ｅで露光を行ったときのプリント理想特性を得るようにしていたが、ネガ画像の画像特徴量（例えば濃度）と露光量とプリント画像の画像特徴量（例えば濃度）との関係を３次元のマップとして記憶しておき、このマップより実際のネガ画像の濃度及び該ネガ画像を露光した際の露光量に対応する理想プリント画像の画像特徴量を求めるようにしてもよい。また、上記関係をネガフィルム１４のフィルム種毎に求めて記憶しておき、プリンタプロセッサ１０にセットされたネガフィルム１４のフィルム種を判断し、判断したフィルム種に対応する前記関係を用いて理想プリント画像の画像特徴量を求めるようにしてもよい。
【０１８７】
更に、上記では１本のネガフィルム１４に対する処理を行う毎に、該ネガフィルム１４から印画紙１６に焼付露光を行った全ての画像（ネガ画像及びプリント画像）を用いて露光量補正値ΔＥを演算していたが、露光量補正値ΔＥを演算する周期、及び露光量補正値ΔＥの演算に用いる画像は上記に限定されるものではなく、例えば一定期間が経過する毎、又は一定本数のネガフィルムを処理する毎、又は一定数の画像の焼付露光を行う毎に、前回露光量補正値ΔＥを演算してから焼付露光を行った全ての画像、又は一定数の画像、又は所定の画像特徴量（例えば画面平均濃度）が所定範囲内に収まっている画像を用いて、露光量補正値ΔＥを演算するようにしてもよい。
【０１８８】
また、上記では（１）式によって露光量Ｅを求めた後に、該露光量Ｅを露光量補正値ΔＥによって補正していたが、露光量補正値ΔＥを露光量演算式に組み込むことにより、露光量の演算及び相違度ｚの値に基づく露光量の補正を同時に行うようにしてもよい。
【０１８９】
また、上記では相違度ｚより露光量補正値ΔＥを演算する方法の一例として、相違度ｚに係数ａを乗じた値を現在設定されている露光量補正値ΔＥ₀ に加算することにより新たな露光量補正値ΔＥを演算するようにした例（第１実施形態の（４）式参照）を説明したが、これに限定されるものではなく、過去に演算した相違度ｚ（例えば１本のネガフィルム１４に記録された各ネガ画像からプリントした各プリント画像について各々演算した相違度ｚの平均値等）を記憶しておき、例えばＮ−１回前から現在に至るＮ回の相違度ｚの演算で各々演算された相違度ｚの値の時系列的な変化に基づいて露光量補正値ΔＥを演算するようにしてもよい。Ｎ＝２とした場合の露光量補正値ΔＥの演算式の一例を次の（10）式に示す。
【０１９０】
ΔＥ＝ａ×ｚ（Ｔ）＋ｂ×（ｚ（Ｔ）−ｚ（Ｔー１))＋ΔＥ₀ …（10）
但し、 ｚ（Ｔ） ：今回演算した相違度
ｚ（Ｔー１）：前回演算した相違度
ΔＥ₀ ：現在設定されている露光量補正値
ａ，ｂ ：係数（ａ＞０，ｂ＞０）
（10）式では、相違度ｚの時系列的な変化傾向に応じて露光量補正値ΔＥの値が調整される。すなわち、今回演算した相違度ｚ（Ｔ）が前回演算した相違度ｚ（Ｔー１）より大きい場合には、相違度ｚの値は時系列的に増加傾向にあると判断できるが、この場合、露光量補正値ΔＥは、（４）式に従って演算した場合と比較してｂ×（ｚ（Ｔ）−ｚ（Ｔー１))だけ値が増加されるので、次回に演算される相違度ｚの値が小さくなるように、すなわちプリンタプロセッサ１０の状態の変動に対する露光量補正の追従性が向上するように、露光量補正値ΔＥを設定できる。また、今回演算した相違度ｚ（Ｔ）が前回演算した相違度ｚ（Ｔー１）より小さい場合には、相違度ｚの値は時系列的に減少傾向にあると判断できるが、この場合、露光量補正値ΔＥは、（４）式に従って演算した場合と比較してｂ×（ｚ（Ｔ）−ｚ（Ｔー１))だけ値が減少されるので、露光量を過剰に補正することを抑制できる。
【０１９１】
（10）式はＮ回の演算で各々得られた相違度ｚに基づいて相違度ｚの時系列的変化を推定し、次回に演算される相違度ｚが０に収束するように露光量補正値ΔＥを求めており、所謂予測関数である。予測関数としては従来より種々の関数が知られており、露光量補正値ΔＥの演算に際しては周知の種々の関数の何れを用いてもよく、最適な関数、アルゴリズムを実験的に求めて適用すればよい。
【０１９２】
更に、上記ではプリンタプロセッサ１０でネガ画像を印画紙１６に複写して通常サイズのプリントを作成する場合に本発明を適用した例を説明したが、この通常プリントの作成と別に行われる、縮小された複数の画像がマトリクス状に配列されたインデックスプリント画像を印画紙１６に複写してインデックスプリントを作成する場合に本発明を適用することも可能である。このインデックスプリントの作成は、プリンタプロセッサ１０に組み込まれた副露光部、或いはプリンタプロセッサ１０と別に設けられたインデックスプリンタによって行われるが、通常プリント画像が理想プリント画像に一致するように通常プリント画像を露光する際の露光を制御すると共に、インデックスプリント画像が理想プリント画像に一致するように、前記副露光部又はインデックスプリンタによりインデックスプリント画像を露光する際の露光を制御すれば、同一のネガ画像から得られる通常プリントとインデックスプリントとの仕上り（画像の各部分の濃度や色バランス等）を略一致させることができる。
【０１９３】
更に、上記では原画像の複写方式として、ネガフィルム１４に記録されたネガ画像の全面を透過した光を印画紙１６に照射することにより画像を露光（所謂面露光）する方式を説明したが、これに限定されるものではなく、例えば原画像に応じて変調したレーザ光によって画像を走査露光する方式や、液晶パネルやＣＲＴ等の表示手段に原画像を表示し、表示手段を透過した光又は表示手段から射出される光によって画像を露光する方式（所謂デジタルプリント方式）を適用することができる。また本発明を、原画像を感光体ドラムに露光し、感光体ドラム上に形成された画像を普通紙やＯＨＰシート等の複写材料に転写することにより原画像を複写材料に複写する、所謂電子写真式の複写機等に適用することも可能である。
【０１９４】
また、上記では原画像としてネガフィルム１４に記録された画像を例に説明したが、これに限定されるものではなく、例えば普通紙やその他の材料に記録された画像や、コンピュータ等の情報処理装置から出力される画像データ等を原画像とすることも可能である。また複写材料としても、印画紙等の感光材料以外に、普通紙やＯＨＰシート等を適用することも可能である。
【０１９５】
以上、本発明の実施形態について説明したが、上記の実施形態は特許請求の範囲に記載した技術的事項の実施態様以外に、以下に記載した技術的事項の実施態様を含んでいる。
【０１９６】
（１）前記記憶手段は、前記原画像の画像特徴量と露光量と標準複写画像の画像特徴量との関係として、標準状態とされた複写手段により原画像を複写材料に所定露光量で露光させ該複写材料に標準複写画像を形成させた場合の、原画像の濃度と複写画像の濃度との関係を記憶しており、前記演算手段は、標準複写画像の推定に際し、複写手段が原画像を複写した際の露光量が前記所定露光量に一致していた場合には、前記記憶手段に記憶されている関係を用いて標準複写画像の推定を行い、複写手段が原画像を複写した際の露光量が前記所定露光量と異なっている場合には、記憶手段に記憶されている前記関係に基づいて、前記複写手段が原画像を前記露光量で複写材料に露光し該複写材料に標準複写画像を形成した場合の原画像の濃度と複写画像の濃度との関係を推定し、推定した関係を用いて標準複写画像の推定を行うことを特徴とする請求項２記載の複写装置。
【０１９７】
上記によれば、原画像の濃度と複写画像の濃度との関係を、所定露光量についてのみ記憶すれば良いので、前記関係を記憶するために必要な記憶容量を小さくすることができ、装置のコストを低減することができる。
【０１９８】
【発明の効果】
以上説明したように請求項１、請求項５乃至請求項７、請求項１０、請求項１１及び請求項１２の各発明は、各種処理条件の変動に拘らず複写画像の画質を高精度で一定とすることができる、という優れた効果を有する。
【０１９９】
請求項２の発明は、上記効果に加え、標準状態とされた複写手段により形成される標準複写画像を精度良く推定することができる、という効果を有する。
【０２００】
請求項３の発明は、上記効果に加え、相違度の値の信頼性を向上させることができる、という効果を有する。
【０２０１】
請求項４の発明は、上記効果に加え、複写画像のうち特に画質の評価で注目される主要部領域の画質を高い精度で一定とすることができる、という効果を有する。
【０２０２】
請求項８の発明は、上記効果に加え、装置のコストを低減することができる、という効果を有する。
【０２０３】
請求項９の発明は、上記効果に加え、複写画像が適正な色バランスとなるように露光量を補正することができる、という効果を有する。
【図面の簡単な説明】
【図１】本実施形態に係るプリンタプロセッサの概略構成図である。
【図２】プリンタ部の光学系、ネガ画像及びプリント画像の測光を行う測光系、制御部及びその周辺の構成を示す概略図である。
【図３】露光処理を示すフローチャートである。
【図４】第１実施形態の露光量補正処理を示すフローチャートである。
【図５】プリンタプロセッサが標準状態のときの、（Ａ）は所定濃度のネガ画像を用いた場合の露光量−プリント濃度特性、（Ｂ）は理想プリント特性の一例、（Ｃ）は理想プリント特性の他の例を各々示す線図である。
【図６】第２実施形態の露光量補正処理を示すフローチャートである。
【図７】第２実施形態における相違度の演算を説明するための線図である。
【図８】第３実施形態の露光量補正処理を示すフローチャートである。
【図９】各画素に重み係数を設定するために用いる複数の濃度範囲の一例を示す概念図である。
【図１０】各画素に重み係数を設定するために用いる複数の色領域の一例を示す概念図である。
【図１１】第４実施形態の露光量補正処理を示すフローチャートである。
【図１２】第５実施形態の露光量補正処理を示すフローチャートである。
【図１３】画像を複数領域に分割するために用いる分割パターンの一例を示す概念図である。
【図１４】第６実施形態の理想プリント画像推定処理を示すフローチャートである。
【図１５】第６実施形態の画像表示・露光量補正処理を示すフローチャートである。
【図１６】単一のセンサによりネガ画像及びプリント画像の測光を行うための測光系の構成を示す概略図である。
【符号の説明】
１０ プリンタプロセッサ
１４ ネガフィルム
１６ 印画紙
２４ キーボード
２８ 色補正フィルタ
３６ ブラックシャッタ
７６ ＣＣＤイメージスキャナ
８６ ＣＣＤイメージセンサ
９４ 制御部
１００ ディスプレイ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a copying apparatus and a copying control method, and more particularly to a copying control method for correcting an exposure amount when an original image is copied on a copying material, and a copying apparatus to which the copying control method can be applied.
[0002]
[Prior art and problems to be solved by the invention]
In general, in photographic processing, a negative film on which an image has been photographed is immersed in various processing solutions using a film developing machine, and then a predetermined reference exposure amount is visualized on the negative film in a photographic printing apparatus. The exposure amount of the image is determined by correcting it according to the density etc. of the printed image, the image is exposed on the photographic paper with the determined exposure amount, and the photographic paper on which the image has been exposed is subjected to various processing liquids by a paper developing machine. A print image corresponding to the photographed image is obtained by immersing the film in the image.
[0003]
However, the image quality of this print image is, for example, the degree of oxidation of the processing liquid in the developing machine, the amount of moisture evaporated from the processing liquid, the amount of the processing liquid mixed in the previous process, or the light amount of the light source of the photographic printing apparatus, the light control filter It varies greatly depending on various processing conditions such as the degree of fading.
[0004]
For this reason, conventionally, a control strip created by exposing a predetermined image to film or photographic paper in advance is processed periodically by each developing machine, and the density of the image visualized on the control strip is determined. In addition to managing the state of the processing liquid of each developing machine by comparing with the reference density, the reference film (so-called eyeball negative) created by exposing the reference image in advance and performing processing such as development is periodically photograph-printed. The reference image is exposed on the photographic paper, and the photographic paper on which the reference image is exposed is processed by a paper developing machine, and the density of the reference image (print image) visualized on the photographic paper is adjusted. Compared to the reference density, the reference exposure amount is corrected and managed so that the influence on the image quality of the printed image due to the change in the various processing conditions is eliminated based on the comparison result. That.
[0005]
However, the management of processing conditions such as the management of the state of the processing liquid using the control strip and the correction and management of the reference exposure using the reference film are complicated and time-consuming work. During the management work, normal processing such as development by each developing machine and exposure in a photographic printing apparatus cannot be performed. For this reason, it is the present condition that processing condition management work can be performed only in a limited time zone, such as before starting the processing of one day, for example, and some processing conditions among various processing conditions are: Since it fluctuates in a short time compared to the cycle in which the processing condition management work is performed, it has been difficult to keep the image quality of the printed image constant.
[0006]
In relation to the above, Japanese Patent Publication No. 7-23952 discloses that the density of the photographic paper (image) processed in the paper development processing unit is measured for each of the three primary colors and integrated over many images. An average density value is calculated for each of the three primary colors from the integrated density value, and it is determined whether or not the average density value is within a predetermined range of values. A printing condition management method is disclosed in which a corrected exposure amount is obtained from the relationship between the exposure amount and the print density, and the printing condition (exposure amount) is corrected.
[0007]
In the technique described in the above publication, the reference exposure amount can be corrected in parallel with the normal processing in accordance with changes in various processing conditions, so that it is compared with the processing condition management work using a control strip or a reference film. Thus, the exposure amount can be corrected in a shorter cycle according to changes in various processing conditions.
[0008]
However, in the above description, if the average of the integrated transmission density is taken over a large number of images (the above-described average density value for each of the three primary colors), the hue represented by the average density value is gray or a constant hue close to gray. Based on this empirical rule (so-called Evans theory), the variation in various processing conditions is determined from the average density value and the exposure amount is corrected. Therefore, it is necessary to accumulate a large number of image data, and it takes time to determine the variation of the processing conditions.
[0009]
The above-mentioned problems are particularly affected by printers with a small average number of processing units per unit time, and it takes a very long time to accumulate a certain number of data, so the determination cycle for fluctuations in various processing conditions is extremely long. Therefore, it is difficult to suppress the change in the image quality of the print image due to the change in the processing conditions.
[0010]
The present invention has been made in consideration of the above-described facts, and an object thereof is to obtain a copying apparatus and a copying control method capable of making the image quality of a copied image constant with high accuracy regardless of changes in various processing conditions. .
[0011]
[Means for Solving the Problems]
In general, assuming that the density of the original image is constant, a certain relationship is established between the exposure amount when the original image is copied to a copy material and the density of the copy image. Based on this fact, the inventor of the present application, when the density of the original image and the exposure amount when the original image is copied to the copying material are known, the various processing conditions are not changed and maintained in the standard state. The density of the copied image (standard copied image) can be estimated, and if there is any difference between the estimated standard copied image and the actual copied image, this difference is caused by any of the various processing conditions in the standard state. The inventors have conceived that it is possible to determine that this is due to deviation from the conditions in the above, and have reached the present invention.
[0012]
For this reason, the copying apparatus according to the first aspect of the present invention includes a first reading unit that reads an original image; Based on the first image data representing the original image obtained by reading by the first reading means, An exposure amount calculation means for calculating an exposure amount when the original image is copied on a copy material, and the original image is copied to a copy material with the exposure amount calculated by the exposure amount calculation means, and the copy image is copied to the copy material. A second reading means for reading a copy image formed on the copy material by the copying means, No. A standard copy image formed on the copy material when the copy means is in a standard state based on the image data of 1 and the exposure amount when the copy means copies the original image onto the copy material The standard copy image is derived by deriving standard copy image data representing the image feature amount or the standard copy image Estimate An image feature amount of the copy image obtained from second image data representing the copy image obtained by reading by the second reading means, an image feature amount of the derived standard copy image, or the derived standard By comparing the image feature amount of the standard copy image obtained from the copy image data, in front Writing Calculating means for calculating a difference between the copied image and the estimated standard copy image; and a correcting means for correcting the exposure amount calculated by the exposure amount calculating means based on the difference calculated by the calculating means; , Including.
[0013]
According to the first aspect of the present invention, the calculating means is based on the first image data representing the original image obtained by reading by the first reading means and the exposure amount when the copying means copies the original image onto the copy material. The standard copy image formed on the copy material when the copy means is in the standard state The standard copy image is derived by deriving the standard copy image data representing the image feature amount or the standard copy image Is estimated. Since this standard copy image is a copy image when the copying means is in the standard state and various processing conditions are not deviated from the processing conditions in the standard state, the actual copy image is different from the standard copy image. In such a case, it can be determined that at least one of various processing conditions when the copying means copies the original image on the copying material and forms the copying image on the copying material is deviated from the processing conditions in the standard state. .
[0014]
For this reason, the calculating means copies the copy image obtained by the reading by the second reading means. The image feature quantity of the copy image obtained from the second image data representing the image feature quantity is compared with the image feature quantity of the derived standard copy image or the image feature quantity of the standard copy image obtained from the derived standard copy image data. And copy images The degree of difference from the standard copy image is calculated, and the correction means corrects the exposure amount based on the calculated degree of difference. Accordingly, the exposure amount is corrected based on the difference between the copy image and the standard copy image resulting from deviation of at least one of the various processing conditions from the processing condition in the standard state. Regardless, the exposure amount is corrected so that the image quality of the copied image is constant.
[0015]
The invention of claim 1 utilizes an empirical rule that the hue represented by the average value of the accumulated transmission density over a large number of images is gray or a constant hue close to gray, as in Japanese Patent Publication No. 7-23952. Instead, the exposure amount is corrected in accordance with changes in various processing conditions based on the degree of difference between the copy image and the estimated standard copy image, and the standard copy image can be estimated in image units. it can. Therefore, it is not always necessary to accumulate data over a large number of images in order to correct the exposure amount in accordance with changes in various processing conditions, and the difference (variation in various processing conditions) is shortened in a cycle shorter than before. Since the exposure amount can be corrected based on this, the image quality of the copy image can be made constant with high accuracy regardless of variations in various processing conditions.
[0016]
The standard copy image can be estimated specifically as follows. That is, the invention described in claim 2 is the case where the original image is exposed to the copy material by the copying means in the standard state obtained in advance and the standard copy image is formed on the copy material. And storage means for storing the relationship between the image feature quantity and exposure quantity of the original image and the image feature quantity of the standard copy image, wherein the computing means is the first image data, and the copying means is the original image. A standard copy image is estimated based on the exposure amount when copied on a copy material and the relationship stored in the storage means.
[0017]
For example, the standard copy image can be estimated by using the characteristics obtained when the copy material such as photographic paper is processed under standard processing conditions published in advance as specifications or the like without using the above-described relationship. Since the standard processing conditions and the processing conditions of the copying means in the standard state do not always coincide with each other, there may be a case where the estimation accuracy of the standard copy image is not sufficient. On the other hand, in the invention of claim 2, when the original image is exposed to the copy material by the copying means in the standard state and the standard copy image is formed on the copy material, the image feature amount and the exposure amount of the original image Since the relationship with the image feature amount of the standard copy image is experimentally obtained in advance and stored in the storage means, and the standard copy image is estimated using the relationship stored in the storage means, the standard state The standard copy image formed by the copied copying means can be estimated with high accuracy.
[0020]
In the present invention, since the standard copy image is obtained by estimation, there is a possibility that an error is included in the image feature amount of the standard copy image used for calculating the difference. In view of the above, claims 3 The described invention is claimed. 1 In the invention, the calculation means uses a plurality of image feature amounts of the copy image and a standard copy image, and compares each image feature amount of the copy image and the standard copy image for each corresponding feature amount. It is characterized by calculating the degree of difference.
[0021]
Claim 3 In this invention, since the degree of difference is calculated using a plurality of image feature amounts of the copy image and the image feature amount of the standard copy image, an error is caused in any one of the plurality of image feature amounts of the standard copy image. Even if such is added, the influence of this error can be reduced, and the reliability of the difference value can be improved.
[0022]
In consideration of the possibility that an error is added to the image feature amount of the standard copy image (the error may be added to the image feature amount of the copy image), the present invention uses as many data as possible. However, according to the above, in order to calculate the degree of difference, a plurality of data (image feature amounts) are acquired from a single image. Compared with the case of acquiring data (image feature amount), the period until a predetermined number of data is accumulated is shortened, and the response speed of exposure amount correction with respect to fluctuations in processing conditions can be improved.
[0023]
By the way, in most cases, evaluation of image quality for an image is generally performed by focusing attention on a specific part (main part) in the image. Claims based on the above 4 The described invention is claimed. 3 In the invention, the calculation means increases the weight of the comparison result of the image feature amount estimated to be related to the main portion in the image, and the comparison result of the image feature amount estimated not to be related to the main portion in the image. The weighting is performed on the comparison result of the image feature amounts of the copy image and the standard copy image so that the weight of the copy image becomes small, and the difference is calculated based on the weighted result.
[0024]
Claim 4 In this invention, the weight of the comparison result of the image feature amount estimated to be related to the main portion in the image is increased, and the weight of the comparison result of the image feature amount estimated not to be related to the main portion in the image is decreased. Thus, if the processing conditions that have a high degree of influence on the image quality of the region corresponding to the main part of the image fluctuate, even if this fluctuation is small, the difference is large. Since the exposure is corrected so that the image quality of the area corresponding to the main part in the image is improved, the image quality of the main area of the copied image, which is particularly noticed in the image quality evaluation, is kept constant with high accuracy. can do.
[0025]
The calculation of the degree of difference by comparing the image feature amount of the copy image with the image feature amount of the standard copy image obtained from the standard copy image data is as follows. 5 As described above, the image feature amount for each pixel of the copy image represented by the second image data (for example, the density value, luminance value, gradation value, etc. for each pixel) and the standard copy represented by the standard copy image data The image feature amount for each pixel of the image can be performed based on a result of comparison for all the pixels constituting the image or each of a plurality of pixels selected according to a predetermined standard.
[0026]
The comparison of the image feature values for each pixel may be performed for all the pixels constituting the image, but pixels that are likely to have an error in the estimation of the standard copy image (for example, the density value is extremely high or If the difference is calculated using the image feature values of a plurality of pixels selected according to a predetermined standard so that the extremely low pixel) is excluded from the difference calculation, It is preferable because a value reflecting the variation more accurately can be obtained.
[0027]
Further, the calculation of the degree of difference by comparing the image feature amount of the copy image with the image feature amount of the standard copy image obtained from the standard copy image data is as follows. 6 As described in the above, the histogram of the copy image is obtained from the second image data, the histogram of the standard copy image is obtained from the standard copy image data, and both histograms are compared as the image feature amount of the copy image and the standard copy image. Based on the result, or the result of comparing the image feature amounts of the corresponding pixels on the histograms of the second image data and the standard copy image data as the image feature amounts of the copy image and the standard copy image It can also be performed based on.
[0028]
The calculation of the degree of difference based on the comparison of the above histograms (in this case, the image feature amount is both histograms) is the whole histogram or a part according to a predetermined standard (for example, the cumulative frequency from the high density side and the low density side of the histogram is This can be done by comparing the histograms excluding the portion up to n% of the total frequency). In addition, as pixels corresponding to both histograms, pixels corresponding to the average value, maximum value, and minimum value in the histogram, or pixels corresponding to the maximum and minimum portions in the histogram are applied. For example, the degree of difference can be calculated based on the difference between the image feature amounts of the corresponding pixels.
[0029]
Further, the calculation of the degree of difference by comparing the image feature amount of the copy image with the image feature amount of the standard copy image obtained from the standard copy image data is as follows: 7 As described above, the copy image and the standard copy image are each divided into a plurality of areas according to a predetermined standard, the image feature quantity is calculated for each area, and the image feature quantity of each area of the copy image and the standard copy image is calculated. It can also be performed based on the result of comparison for each corresponding region.
[0030]
The image may be divided into a plurality of areas, for example, according to a predetermined division pattern, or an area (person area) estimated to correspond to a person existing in the image is extracted. The image may be divided into a human area and a non-human area, or an area (background area) estimated to correspond to the background existing in the image is extracted, and the image is divided into a background area and a non-background area You may make it do. In addition, as described above, the image is divided into the person area and the non-person area, and the comparison result of the image feature amount of each area is increased in weight of the comparison result of the image feature amount of the person area. If the difference is calculated by weighting so that the weight of the comparison result of the feature amount is small, the image quality of the person area that is particularly noted in the image quality evaluation among the copied images can be made constant with high accuracy. It is preferable because it is possible.
[0031]
Claim 8 The invention described in claim 1 to claim 7 In any one of the inventions, the first reading means and the second reading means share a single image reading element for reading an image, and the original reading image and the copied image are read by the image reading element, respectively. It is characterized by.
[0032]
Note that the original image and the copy image are read by the single image reading sensor, for example, the image reading sensor is disposed at a position where light transmitted through or reflected by one of the original image and the copy image can be received, and the other This can be realized by configuring the light transmitted or reflected through the image to be guided by guide means such as an optical fiber. Claim 8 According to the invention, since the original image and the copy image can be read by the single image reading sensor, the cost of the apparatus can be reduced.
[0033]
Claim 9 The invention described in claim 1 to claim 8 In any one of the inventions, the second reading means separates and reads a copy image into a plurality of component colors, and the correction means reads second image data obtained by reading by the second reading means. Based on the above, the pixel having the maximum luminance on the copy image is judged, and the exposure amount is corrected for each component color so that the hue of the pixel is white.
[0034]
In general, the hue of the portion of the copied image having the maximum luminance is white or a hue very close to white. Claim 9 In the invention, the pixel having the maximum luminance on the copy image is determined based on the second image data, and the exposure amount is corrected so that the hue of the pixel is white. Therefore, the copy image has an appropriate color balance. The exposure amount can be corrected so that
[0035]
Claim 1 0 The copying apparatus according to the described invention includes first reading means for reading an original image; Based on the first image data representing the original image obtained by reading by the first reading means, An exposure amount calculation means for calculating an exposure amount when the original image is copied on a copy material, and the original image is copied to a copy material with the exposure amount calculated by the exposure amount calculation means, and the copy image is copied to the copy material. A second reading means for reading a copy image formed on the copy material by the copying means, No. A standard copy image formed on the copy material when the copy means is in a standard state based on the image data of 1 and the exposure amount when the copy means copies the original image onto the copy material The standard copy image is derived by deriving standard copy image data representing Estimation means for estimating the image, display means for displaying the copy image read by the second reading means and the standard copy image estimated by the estimation means, and input means for inputting a correction value for the exposure amount And a correction means for correcting the exposure amount calculated by the exposure amount calculation means based on the exposure value correction value input via the input means.
[0036]
Claim 1 0 In the present invention, the standard copy image is estimated by the estimation means. Standard copy image data derived from the standard copy image data The display means displays the copy image read by the second reading means and the standard copy image estimated by the estimation means, so that the displayed copy image and the standard copy image are compared and referred to. An operator or the like can easily visually recognize whether or not the processing conditions of the copying means have changed. When the operator determines that the processing conditions of the copying unit are fluctuating and inputs a correction value for the exposure amount via the input unit, the correction unit corrects the exposure amount based on the input correction value. Regardless of variations in processing conditions, the image quality of a copied image can be made constant with high accuracy.
[0037]
Claim 1 1 The copy control method according to the described invention reads an original image, Based on first image data representing the original image obtained by reading the original image, An exposure amount when the original image is copied to a copy material is calculated, the copy material is exposed to the copy material with the calculated exposure amount, a copy image is formed on the copy material, and the copy means While reading the copy image formed on the copy material, Said A standard copy image formed on the copy material when the copy means is in a standard state based on the first image data and the exposure amount when the copy means copies the original image onto the copy material. The standard copy image is derived by deriving standard copy image data representing the image feature amount or standard copy image Estimate The image feature amount of the copy image obtained from the second image data representing the copy image obtained by reading the copy image, the image feature amount of the derived standard copy image, or the derived standard copy image data By comparing the image feature amount of the standard copy image obtained from in front Writing The degree of difference between the copied image and the estimated standard copy image is calculated, and the exposure amount when the original image is copied onto the copy material is corrected based on the calculated difference.
[0038]
Claim 1 1 In the invention, the standard formed on the copy material when the copy means is in the standard state based on the first image data representing the original image and the exposure amount when the copy means copies the original image onto the copy material. Copy image Standard copy image by deriving standard copy image data representing image feature quantity or standard copy image And calculating a difference between the read copy image and the estimated standard copy image, and correcting an exposure amount when the original image is copied on a copy material based on the calculated difference. Similar to the first aspect of the invention, the image quality of the copy image can be made constant with high accuracy regardless of changes in various processing conditions.
[0039]
Claim 1 2 The copy control method according to the described invention reads an original image, Based on first image data representing the original image obtained by reading the original image, An exposure amount when the original image is copied to a copy material is calculated, the copy material is exposed to the copy material with the calculated exposure amount, a copy image is formed on the copy material, and the copy means While reading the copy image formed on the copy material, Said A standard copy image formed on the copy material when the copy means is in a standard state based on the first image data and the exposure amount when the copy means copies the original image onto the copy material. The standard copy image is derived by deriving standard copy image data representing The read copy image and the estimated standard copy image are displayed, and the exposure amount when the original image is copied to the copy material is corrected by the input exposure amount correction value.
[0040]
Claim 1 2 In the invention, the standard formed on the copy material when the copy means is in the standard state based on the first image data representing the original image and the exposure amount when the copy means copies the original image onto the copy material. Copy image Standard copy image by deriving standard copy image data representing The read copy image and the estimated standard copy image are displayed, and the exposure amount when the original image is copied onto the copy material is corrected by the input exposure amount correction value. 0 Similar to the invention, the image quality of the copied image can be made constant with high accuracy regardless of the variation of various processing conditions.
[0041]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.
[0042]
[First Embodiment]
FIG. 1 shows the overall configuration of a printer processor 10 as a copying apparatus according to the present invention. The printer processor 10 is externally covered with a casing 12, and a printer unit 18 that exposes an image recorded on a negative film 14 onto the photographic paper 16, and color development / bleach fixing for the photographic paper 16 on which the image is exposed. A processor unit 64 that performs processing such as washing and drying.
[0043]
First, the configuration of the printer unit 18 will be described. A work table 20 is attached to the printer processor 10 on the left side in FIG. 1 so as to protrude from the casing 12. On the upper surface of the work table 20, a negative carrier 22 on which a negative film 14 is set, and an operator A keyboard 24 for inputting various commands and data. 0 Corresponding to the input means). The negative carrier 22 includes conveyance roller pairs 80A and 80B (see FIG. 2). The conveyance roller pairs 80A and 80B are connected to the drive shafts of the motors 82A and 82B, respectively, and rotate when the driving force of the motors 82A and 82B is transmitted to convey the negative film 14.
[0044]
A light source 26 that emits exposure light for printing an image recorded on the negative film 14 is disposed below the conveyance path of the negative film 14 by the negative carrier 22. As shown in FIG. 2, the color correction filter 28, the diffusion box 30, and the distribution prism 32 are sequentially arranged on the light emission side of the light source 26. The color correction filter 28 is composed of three sets of C (cyan), M (magenta), and Y (yellow) filters that can move forward and backward independently of each other with respect to the exposure optical path. The conveyance path of the negative film 14 is formed between the diffusion box 30 and the distribution prism 32, and the distribution prism 32 distributes the light transmitted through the negative film 14 in two directions.
[0045]
On the optical path of one of the lights distributed in two directions by the distributing prism 32 (light that goes upward in the vertical direction), an exposure lens 34 that can change the magnification of the image to be exposed, and a black shutter 36, a mirror 38 (see FIG. 1) that reflects exposure light in a substantially right angle direction is disposed in order. The distribution prism 32, the exposure lens 34, the black shutter 36, and the mirror 38 are accommodated in a cover 40 formed on the upper side of the negative carrier 22. The exposure light reflected by the mirror 38 is applied to the photographic paper 16 located at the exposure position in the exposure chamber 42, and the image on the negative film 14 is exposed to the photographic paper 16.
[0046]
As shown in FIG. 2, on the other optical path of the light distributed by the distribution prism 32, a projection optical system 84 and a CCD image sensor 86 as a first reading unit are arranged in this order. The CCD image sensor 86 divides the entire image (one frame) recorded on the negative film 14 into a large number of pixels (for example, 256 × 256 pixels), and each pixel is R (red), G (green), B (blue). Measure the light by separating it into three colors.
[0047]
At the signal output terminal of the CCD image sensor 86, an amplifier 88 for amplifying the signal output from the CCD image sensor 86, an analog-digital (A / D) converter 90, and 3 × 3 for correcting the sensitivity of the CCD image sensor 86. Matrix circuits 92 are connected in order. The 3 × 3 matrix circuit 92 is connected to an input / output port 94D of a control unit 94 that includes a microcomputer and its peripheral devices. The control unit 94 includes a CPU 94A, a ROM 94B, a RAM 94C, and an input / output port 94D, which are connected to each other via a bus.
[0048]
Further, the control unit 94 includes nonvolatile storage means 94E that can rewrite stored contents, such as an EEPROM or a RAM connected to a backup power source, and the storage means 94E is connected to an input / output port 94D. . The specific configuration of the storage unit 94E is not limited to the above, and a nonvolatile storage medium such as a floppy disk, a hard disk, a magneto-optical disk, a memory card, etc. that can rewrite the storage contents, and the storage medium It is also possible to configure it with a driver for writing and reading information.
[0049]
The color correction filter 28 is connected to the input / output port 94D of the control unit 94 via a driver 96 that drives each filter of the color correction filter 28, and motors 82A and 82B are connected to each other via drivers 98A and 98B. Has been. Also connected to the input / output port 94D are a display 100 made of LCD or CRT, a keyboard 24, and a screen detection sensor 102 for detecting the amount of light transmitted through the negative film 14 disposed on both sides of the optical axis of the light source 26. Yes. The control unit 94 and its peripheral circuits described above are accommodated in a space 44 (see FIG. 1) below the exposure chamber 42.
[0050]
On the other hand, a mounting portion 46 is provided at the upper right corner of the casing 12 in FIG. The mounting portion 46 is detachably mountable with a paper magazine 50 for storing a long photographic printing paper 16 as a copying material wound around a reel 48 in layers. A pair of rollers 52 is disposed in the vicinity of the mounting portion 46, and the photographic paper 16 drawn out from the paper magazine 50 and fed into the casing 12 (inside the exposure chamber 42) is sandwiched by the pair of rollers 52 and horizontally. Along the exposure chamber 42.
[0051]
A winding roller 54 is disposed near the upper left corner in the exposure chamber 42 in FIG. The photographic paper 16 transported along the horizontal direction is wound around the winding roller 54, the transport direction is changed by approximately 90 °, and transported downward in the vertical direction, and reaches the exposure position. A first stock portion 56 is formed between the roller pair 52 and the winding roller 54 to guide and stock the photographic paper 16 in a substantially U shape.
[0052]
Below the exposure position in the exposure chamber 42, rollers 58A, 58B, and 58C are arranged. The photographic paper 16 on which the image of the negative film 14 is exposed at the exposure position is transported to the processor unit 64 (described later) after the transport direction is changed by approximately 90 ° by the rollers 58A, 58B, and 58C. A cutter 60 is disposed on the downstream side of the roller 58A. The cutter 60 cuts the rear end of the photographic paper 16 on which the image is exposed. The unexposed photographic paper 16 cut in the cutter 60 and remaining in the exposure chamber 42 can be rewound into the paper magazine 50 again.
[0053]
Further, a second stock portion 62 is formed between the rollers 58A and 58B for guiding and stocking the photographic printing paper 16 exposed with the image in a substantially U shape. The second stock unit 62 absorbs the difference in processing time between the printer unit 18 and the processor unit 64. Although not shown, a cut mark applicator is provided in the vicinity of the exposure position in the exposure chamber 42 for applying a cut mark to the photographic paper for cutting the photographic paper 16 for each image frame.
[0054]
Next, the configuration of the processor unit 64 will be described. The processor unit 64 is provided with a color developing tank 66 in which a color developer is stored, a bleach-fixing tank 68 in which a bleach-fixing solution is stored, and a plurality of rinsing tanks 70 in which washing water is stored. 16 is sequentially conveyed through the color developing tank 66, the bleach-fixing tank 68, and the plurality of rinsing tanks 70, so that the processes of color development, bleach-fixing, and water washing are sequentially performed. As a result, the image exposed on the photographic paper 16 is visualized. The washed photographic paper 16 is conveyed to a drying unit 72 adjacent to the rinsing tank 70. In the drying unit 72, the photographic paper 16 is wound around a roller and dried by exposure to high-temperature air.
[0055]
The photographic paper 16 is sandwiched between a pair of rollers (not shown), and is discharged from the drying unit 72 at a constant speed after the drying process is completed. A portion from the color developing tank 66 to the drying unit 72 of the processor unit 64 corresponds to the copying unit of the present invention together with the printer unit 18. On the downstream side of the drying unit 72, there are a cut mark sensor 74 for detecting a cut mark applied to the photographic paper 16, a CCD image scanner 76 as a second reading unit of the present invention, and a cutter 78 for cutting the photographic paper 16. They are installed in order.
[0056]
As shown in FIG. 2, the CCD image scanner 76 includes a light source 76A and a CCD image sensor 76B. Light that is emitted from the light source 76A and reflected by the photographic paper 16 is incident on the CCD image sensor 76B, and the same number of print images (one frame) recorded on the photographic paper 16 as the CCD image sensor 86 that measures the negative image. Are divided into a large number of pixels (for example, 256 × 256 pixels), and each pixel is separated into three colors of R, G, and B and photometrically measured. The signal output terminal of the CCD image sensor 76B is connected to the input / output port 94D of the control unit 94 via the amplifier 104, the A / D converter 106, and the 3 × 3 matrix circuit 108 for correcting the sensitivity of the CCD image sensor 76B. Yes.
[0057]
Although not shown, the cut mark sensor 74 and the cutter 78 are also connected to the control unit 94. Based on the detection result of the cut mark by the cut mark sensor 74, the control unit 94 controls the operation of the cutter 78 so that the photographic paper 16 is cut for each image frame. The photographic paper 16 cut for each image frame by the cutter 78 is discharged out of the body of the printer processor 10.
[0058]
Next, as an operation of the first embodiment, first, an exposure process executed by the printer unit 18 by the control unit 94 will be described with reference to a flowchart of FIG. In the flowchart of FIG. 3, the negative film 14 that has been imaged and recorded and processed by a film processor (not shown) is set on the negative carrier 22, and the operator instructs the start of the exposure process. This is executed by the CPU 94A of the control unit 94.
[0059]
In step 150, the negative film 14 is conveyed by the negative carrier 22. In step 152, the position of the image (negative image) recorded on the negative film 14 is determined by monitoring the signal output from the screen detection sensor 102, and it is determined whether or not the negative image has reached the exposure position. If the determination is negative, the process returns to step 150 and the conveyance of the negative film 14 is continued.
[0060]
If the determination in step 152 is affirmed, in step 154, the conveyance of the negative film 14 by the negative carrier 22 is stopped, and the negative image that has reached the exposure position is positioned at the exposure position. In step 156, the negative image positioned at the exposure position is measured by the CCD image sensor 86, and R, G, and R output from the CCD image sensor 86 through the amplifier 88, the A / D converter 90, and the 3 × 3 matrix circuit 92 are measured. Negative image data for each B (corresponding to the first image data of the present invention) is captured, and the captured negative image data is stored in the storage means 94E.
[0061]
In the next step 158, the screen average density d is based on the negative image data captured in step 156. _i (I = R, G, or B) is calculated, and the exposure amount E is calculated according to a predetermined exposure amount calculation formula. _0i Is calculated. As an exposure calculation formula, the following formula (1) can be used as an example.
[0062]

However, the meaning of each symbol is as follows.
[0063]
LM: magnification slope coefficient. It is preset according to the enlargement ratio determined by the type of negative film and the print size.
[0064]
CS: Color slope coefficient. It is prepared for each type of negative film, and there are for underexposure and overexposure. It is determined whether the average density of the image frames to be printed is under or over the standard negative density value, and either under exposure or over exposure is selected.
[0065]
dN: Standard negative density value.
d: Screen average density value of image frames to be printed
PB: Correction balance value for standard color paper. It is determined according to the type of color paper.
[0066]
LB: Correction balance value for standard printing lens. It is determined according to the type of lens used for printing.
[0067]
MB: Correction value (master balance value) for fluctuations in the amount of light source and changes in paper development performance.
[0068]
NB: Negative balance (color balance) value determined by the characteristics of the negative film.
[0069]
K ₂ : Color correction amount.
K ₁ : Density correction amount.
[0070]
In step 158, the exposure amount E calculated as described above is used. ₀ On the basis of the position of each of the C, M, and Y filters constituting the color correction filter 28 and the exposure time t. ₀ (The opening time of the black shutter 36) is determined. This step 158 corresponds to the exposure amount calculation means of the present invention.
[0071]
In the next step 160, the exposure amount correction value ΔE is taken in, and the exposure amount E calculated in step 158 is obtained. ₀ Correction is performed with the exposure amount correction value ΔE taken in. The initial value of the exposure correction value ΔE is set to 0 (= no correction), and the value is set by an exposure correction process described later. In the first embodiment, the exposure time t is used as the exposure correction value ΔE. ₀ The exposure time correction value Δt for correcting the correction is used. As an example, the corrected exposure time t is obtained according to the following equation (2).
[0072]
t = t ₀ + Δt (2)
In step 162, the exposure amount corrected in step 160 (exposure time t ₀ Is stored in the storage unit 94E in correspondence with the negative image data stored in step 156. In step 164, the color correction filter 28 and the black shutter 36 are operated based on the corrected exposure amount E. Specifically, the driver 96 is instructed to move each filter of the color correction filter 28 to the position determined in step 158, and the black shutter 36 is opened for a time corresponding to the corrected exposure time t. As a result, the image of the negative film 14 positioned at the exposure position is exposed on the photographic paper 16 with the corrected exposure amount E.
[0073]
In the next step 166, it is determined whether or not all the images recorded on the negative film 14 have been exposed. When determination is denied, it returns to step 150 and repeats the said process. Then, when the determination is affirmed, the process is terminated.
[0074]
Next, the exposure amount correction process according to the first embodiment will be described with reference to the flowchart of FIG. In the flowchart of FIG. 4, the photographic paper 16 on which an image is exposed by the above-described exposure process is immersed in the processing liquid stored in each processing tank of the processor unit 64 and processed (by this, When the leading edge of the photographic paper 16 is discharged from the drying unit 72, an interrupt is generated and executed by the CPU 94A of the control unit 94.
[0075]
In step 170, the printing paper 16 is conveyed. In step 172, the position of the image (print image) formed on the photographic paper 16 is determined by monitoring the signal output from the CCD image scanner 76, and the photometric position of the photographic paper 16 by the CCD image scanner 76 is determined. It is determined whether the print image has arrived. If the determination is negative, the process returns to step 170 and the conveyance of the photographic paper 16 is continued.
[0076]
If the determination in step 172 is affirmative, the conveyance of the photographic paper 16 is stopped in step 174, and the print image that has reached the photometric position is positioned at the photometric position. In step 176, the image positioned at the photometric position is measured by the CCD image scanner 76, and R, G, B output from the CCD image scanner 76 via the amplifier 104, the A / D converter 106, and the 3 × 3 matrix circuit 108. Each print image data (corresponding to the second image data of the present invention) is taken in.
[0077]
In step 178, negative image data and exposure amount data corresponding to the print image captured in step 176 are searched for from the negative image data and exposure amount data stored in the storage unit 94E. Capture. The processing from step 178 to step 192 described later corresponds to the computing means of the present invention.
[0078]
In steps 156 and 162 of the exposure processing described above, negative image data and exposure amount data are stored in association with identification information for identifying negative image data and exposure amount data corresponding to each negative image. This is preferable because it facilitates retrieval of data corresponding to the print image. The setting of the identification information and the data search can be performed as follows as an example. That is, a first counter and a second counter are provided, and the first counter is incremented every time a negative image is read, and when the negative image data and the exposure amount data are stored, the first counter is used as identification information. The count value of 1 counter is stored in correspondence. The second counter counts up every time a print image is read.
[0079]
Thereby, the search for the data corresponding to the print image can be realized by searching the negative image data and the exposure amount data stored in correspondence with the identification information matching the current count value of the second counter. Note that the first counter and the second counter are predetermined conditions for determining a process break (for example, exposure of all images recorded on one negative film 14 has been completed, or exposed photographic paper 16 is all cleared from the exposure chamber 42), the count value may be cleared to zero.
[0080]
By the way, in the present embodiment, a predetermined exposure amount e as shown by a solid line in FIG. _T The relationship between the negative density d and the print density D at the time of exposure is stored in advance. The relationship between the negative density d and the print density D is such that the printer processor 10 is in the standard state (so that various processing conditions such as the state of the processing liquid and the light amount of the light source 26 are the processing conditions in the standard state). After the adjustment, a predetermined negative image whose density is measured in advance for each pixel by the CCD image sensor 86 is converted into a predetermined exposure amount e. _T Is obtained by performing an experiment in which the density of the print image of the photographic paper 16 exposed to the photographic paper 16 and subjected to processing such as development by the processor unit 64 is measured for each pixel.
[0081]
This relationship represents the relationship between the negative density d and the print density D when the printer processor 10 is in the standard state. Hereinafter, this relationship is referred to as a print ideal characteristic. In the next step 180, the ideal print characteristics are taken in.
[0082]
The ROM 94B also stores the relationship between the exposure amount E and the print density D as shown in FIG. The relationship between the exposure amount E and the print density D is also adjusted to a predetermined density d after the printer processor 10 is adjusted to the standard state as described above. ₀ An experiment for measuring the density of each print image of the photographic paper 16 that has been subjected to processing such as development by the processor unit 64 by repeatedly performing printing exposure on the photographic paper 16 with various exposure amounts E being changed. It is the one that was sought by doing.
[0083]
The relationship between the exposure amount E and the print density D is the same as the above-mentioned ideal print characteristics as described in claim 2 wherein the original image is exposed to the copy material by the copying means in the standard state and the standard copy image is applied to the copy material. Corresponds to the relationship between the image feature amount and the exposure amount of the original image and the image feature amount of the standard copy image ”.
[0084]
In step 182, the exposure amount e represented by the exposure amount data captured in step 178 is the predetermined exposure amount e obtained when the print ideal characteristic is obtained. _T It is determined whether or not it matches. If the determination is affirmative, the process proceeds to step 186, and after step 186, the process is performed using the previously captured print ideal characteristics as they are.
[0085]
On the other hand, if the determination in step 182 is negative, the process proceeds to step 184, where the ideal print characteristics captured previously are corrected according to the exposure amount e represented by the exposure amount data captured in step 178.
[0086]
Specifically, based on the relationship between the exposure amount E stored in the ROM 94B and the print density D (see FIG. 5A), the exposure density e and the predetermined density d. ₀ Print density D when the negative image is exposed. _x Ask for. As an example, as shown in FIG. 5A, the exposure amount represented by the exposure amount data is e. ₁ Print density D _x As concentration D ₁ The exposure amount represented by the exposure amount data is e ₂ Print density D _x As concentration D ₂ Is obtained.
[0087]
Next, on the chart showing ideal print characteristics, the negative density is d ₀ , Print density is D _x The ideal print characteristics are translated so as to pass through the points. For example, print density D _x Is the concentration D ₁ If the negative concentration is d ₀ , Print density is D ₁ Point P ₁ The print ideal characteristic is translated so as to pass through (the dashed line in FIG. 5B). Print density D _x Is the concentration D ₂ If the negative concentration is d ₀ , Print density is D ₂ Point P ₂ The print ideal characteristic is translated so as to pass through (the two-dot chain line in FIG. 5B). Thereby, an ideal print characteristic when exposure is performed with the exposure amount e represented by the exposure amount data is obtained.
[0088]
When the process of step 184 is performed, the process proceeds to step 186. In this case, the processes after step 186 are performed using the print ideal characteristics obtained by the process of step 184.
[0089]
As described above, the predetermined exposure amount e _T Instead of storing only the ideal print characteristics when the exposure is performed and using the print ideal characteristics in parallel, a plurality of different exposures are shown as indicated by solid lines in FIG. Quantity (eg e _a , E _b , E _c ), The ideal print characteristics when the exposure is performed may be obtained and stored. In this case, although there is a drawback that the storage capacity necessary for storing the print ideal characteristics is large, the parallel movement amount of the print ideal characteristics for obtaining the print ideal characteristics at the exposure amount e represented by the exposure amount data is small. Since the probability is high, the probability that a more accurate print ideal characteristic can be obtained increases.
[0090]
On the other hand, in step 186, the screen average density d of the negative image is based on the negative image data captured in step 178. _AV Is calculated. In the next step 188, the screen average density d of the negative image _AV And the average screen density DX of the print image based on the print ideal characteristics described above. _AV Ask for. Screen average density DX of this print image _AV Is obtained using the ideal print characteristics, so that when the printer processor 10 is in the standard state, the screen average density d _AV The negative print image is exposed to the photographic paper 16 with the exposure amount e represented by the exposure amount data, and an ideal print image (book) estimated to be formed on the photographic paper 16 when processing such as development is performed by the processor unit 64. This corresponds to a screen average density (an image feature amount of the standard copy image) of the invention (corresponding to the standard copy image of the invention). Is the mark This corresponds to the derivation of the image feature amount of the quasi-copy image.
[0091]
In step 190, based on the print image data captured in step 176, the screen average density D of the print image. _AV (Corresponding to the image feature amount of the copy image) is calculated, and in step 192, the screen average density D of the print image _AV And screen average density DX of the ideal print image _AV As an example, the degree of difference z is calculated according to the following equation (3).
[0092]
z = DX _AV -D _AV ... (3)
The degree of difference z obtained from the equation (3) is the screen average density DX of the ideal print image. _AV And the average density D of the actual print image _AV The average print density DX of the ideal print image _AV Is an estimated value of the screen average density of the print image when the printer processor 10 is in the standard state. If the value of the dissimilarity z is other than 0, any of the various processing conditions of the printer processor 10 is standard. It can be determined that there is a deviation from the processing conditions in the state.
[0093]
Therefore, in the next step 194, the exposure correction value ΔE is calculated based on the value of the difference z calculated in step 192. In the first embodiment, the exposure time correction value Δt is used as the exposure amount correction value ΔE. As an example, the exposure time correction value Δt is obtained by the following equation (4), and the calculation result is stored in the RAM 94C or the like. This step 194 corresponds to the correction means of the present invention together with the exposure processing step 160 (see FIG. 3).
[0094]
Δt = (a × z) + Δt ₀ ... (4)
Where a: coefficient (a> 0)
Δt ₀ : Exposure time correction value currently set
By the above, the screen average density D of the actual print image _AV Is the screen average density DX of the ideal print image _AV If it is higher, the sign of the term (a × z) becomes negative, and as is clear from the equation (2), the exposure time correction value Δt is set so that the exposure time t is shortened and the print density D is lowered. It is changed and set. Also, the average screen density D of the actual print image _AV Is the screen average density DX of the ideal print image _AV If it is lower, the sign of the term (a × z) becomes positive, the exposure time correction value Δt is changed and set so that the exposure time t becomes longer and the print density D becomes higher.
[0095]
Note that the value of the coefficient a can be determined based on the slope of the relationship between the exposure amount E and the print density D shown in FIG. However, since the exposure correction process is repeatedly executed, the exposure time correction value Δt is also repeatedly updated by the closed loop control. Therefore, when the value of the coefficient a is relatively small, the change amount (a × z) of the exposure time correction value Δt is small, so that the stability as the control system is high but the response is slow, and the value of the coefficient a Is relatively large, the change amount (a × z) of the exposure time correction value Δt becomes large, so that the response is quick, but the stability as a control system is low. For this reason, it is preferable to experimentally obtain the optimum value of the coefficient a.
[0096]
In the next step 300, it is determined whether or not the above-described processing has been performed on all the images formed on the photographic paper 16. When determination is denied, it returns to step 170 and repeats steps 170-300. As a result, an exposure correction value ΔE (more specifically, an exposure time correction value Δt) is calculated for each print image recorded on the photographic paper 16 and stored in the RAM 94C or the like.
[0097]
If the determination in step 300 is affirmative, the routine proceeds to step 302 where the average value of the exposure amount correction values ΔE (more specifically, the exposure time correction value Δt) calculated for each print image is calculated and calculated. The average value is set as the actual exposure correction value ΔE (more specifically, the exposure time correction value Δt), and the process ends.
[0098]
As a result, when the exposure process is performed next time, printing exposure of the negative image onto the photographic paper 16 is performed using the exposure amount E corrected in step 160 (see FIG. 3) with the newly set exposure amount correction value ΔE. Therefore, printing exposure of the negative image is performed so that the density of the print image matches the density of the ideal print image regardless of the change in the state of the printer processor 10.
[0099]
In the above description, the negative image data is temporarily stored in the storage means 94E in the exposure process, and the screen average density of the negative image is calculated in the exposure amount correction process. However, the present invention is not limited to this. The average image density of the negative image may be calculated in step S4, and the calculation result may be stored in the storage means 94E.
[0100]
In the above description, the screen average density is used as the image feature amount. However, the present invention is not limited to this, and the dissimilarity z is calculated using the image feature amount such as the maximum value, minimum value, and intermediate value of the density. You may do it.
[0101]
[Second Embodiment]
Next, a second embodiment of the present invention will be described. In addition, since this 2nd Embodiment is the structure same as 1st Embodiment, it attaches | subjects the same code | symbol to each part, abbreviate | omits description of a structure, and demonstrates the effect | action of this 2nd Embodiment below.
[0102]
In the second embodiment, as density value measurement points for calculating the degree of difference z, a plurality of different negative density values are predetermined on the negative density axis (in FIG. 7, as an example, four measurements are performed). Points p1 to p4 are shown). Note that the measurement point is preferably determined by excluding a range where the concentration is extremely high or extremely low.
[0103]
As will be described later, in the second embodiment, the dissimilarity z is calculated using the density value D on the print image and the density value DX on the ideal print image of the pixel corresponding to each measurement point. Since the linearity of the ideal print characteristic is lowered in a very high or extremely low range, the accuracy of the density value DX of the ideal print image is also low in this range. As described above, if the measurement point is determined excluding a range where the density is extremely high or extremely low, the difference z is calculated without using low-precision data as the density value DX of the ideal print image. Therefore, a value that accurately reflects variations in various processing conditions of the printer processor 10 can be obtained as the difference z.
[0104]
Next, the exposure correction processing according to the second embodiment will be described with reference to the flowchart of FIG. In the exposure correction processing according to the second embodiment, steps 200 to 208 and steps 220 and 222 are performed instead of steps 186 to 194 (see FIG. 4) of the exposure correction processing described in the first embodiment. Do. In the second embodiment, steps 178 to 184 and steps 200 to 208 described in the first embodiment correspond to the calculation means of the present invention.
[0105]
In step 200, pixels having density values corresponding to the plurality of measurement points are selected from the negative image based on the negative image data captured in step 178. In the next step 202, based on the print ideal characteristics (shown by solid lines in FIG. 7), the density values on the ideal print image of the pixels having density values corresponding to any of the plurality of measurement points on the negative image. DX (image feature amount of standard copy image) is obtained. This can be realized by converting a plurality of negative density values corresponding to each measurement point into print density values using print ideal specification. The processing of step 202 is a standard copy image estimation, more detailed description. Is the mark This corresponds to the derivation of the image feature amount of the quasi-copy image.
[0106]
In step 204, pixel data corresponding to the pixel selected in step 200 is selected from the print image data captured in step 178. FIG. 7 shows an example of the result of plotting the density value D represented by the pixel data selected from the print image data in step 204 on the chart indicating the print ideal characteristics. Assuming that the relationship (current print characteristics) between the negative density d and the print density D in the actual print image is approximated by a straight line based on the plotted result, at least one of the various processing conditions of the printer processor 10 is in the standard state. If there is a deviation from the processing conditions in FIG. 7, the current print characteristics are deviated from the ideal print characteristics, as indicated by the broken line in FIG.
[0107]
Therefore, in step 206, the deviation of the current print characteristic from the print ideal characteristic is calculated as the difference z. Specifically, as shown in the following equation (5) (in equation (5), the number of measurement points is m), a plurality of density values D in the print image derived or selected in steps 202 and 204 are displayed. _j (J in the equation (5) is a code given for each measurement point) and a plurality of density values DX in the ideal print image _j The weighting factor w is calculated for each measurement point and the difference for each measurement point is determined for each measurement point. _j The degree of difference z is obtained by weighting and accumulating.
[0108]
[Expression 1]

[0109]
Note that the weighting coefficient w in the equation (5) _j Is based on whether or not the negative density d corresponding to each measurement point is a value with a high probability that it is the density of a main part (for example, a region corresponding to a person in the image) in the negative image. The weight of a measurement point with a high probability of partial concentration can be determined to be large. This weighting factor setting is more specifically claimed. 4 It corresponds to the calculation means described in. As a result, when the processing condition that has a high degree of influence on the image quality of the main area of the image changes, the absolute value of the difference z increases even if this change is small. The exposure amount is corrected so that the image quality becomes constant with high accuracy.
[0110]
In the next step 208, based on the value of the degree of difference z calculated above, the exposure amount correction value ΔE (more specifically, the exposure time) in the same manner as in step 194 of the exposure amount correction process described in the first embodiment. The correction value Δt) is calculated. In step 220, based on the print image data captured in step 178, the pixel having the maximum luminance value (the pixel having the minimum average density of R, G, and B) on the actual print image is determined, and the pixel data From the print image data.
[0111]
In the second embodiment, the exposure correction value ΔE is composed of an exposure time correction value Δt and a color balance correction value ΔC. In the next step 222, the color balance correction value ΔC of the exposure amount correction value ΔE is set so that the hue of the pixel captured in step 220 is white (R, G, B density is constant). These steps 220 and 222 are performed together with step 160 (see FIG. 3) of the exposure process. 9 This corresponds to the correction means described in (1).
[0112]
Thus, the next time exposure processing is performed, in step 160 (see FIG. 3), the exposure processing is performed based on the newly set exposure amount correction value ΔE composed of the exposure time correction value Δt and the color balance correction value ΔC. In addition to the exposure time correction based on the exposure time correction value Δt, the position of each filter of the color correction filter 28 is also corrected based on the color balance correction value ΔC, and the negative exposure on the photographic paper 16 is performed using the corrected exposure amount E. Since the exposure of the image is performed, the negative of the print image so that the density of the print image matches the density of the ideal print image and the hue of the portion where the brightness of the print image is maximum is white regardless of the change in the state of the printer processor 10. The image is exposed on the photographic paper 16.
[0113]
[Third Embodiment]
Next, a third embodiment of the present invention will be described. Since the third embodiment has the same configuration as that of the first embodiment, the same reference numerals are given to the respective parts and description of the configuration is omitted, and the exposure amount correction processing according to the third embodiment will be described below. Will be described with reference to the flowchart of FIG.
[0114]
In the exposure correction processing according to the third embodiment, steps 210 to 216 are performed instead of the steps 200 to 208 (see FIG. 6) of the exposure correction processing described in the second embodiment. In the third embodiment, steps 178 to 184 and steps 210 to 216 described in the first embodiment correspond to the calculation means of the present invention.
[0115]
In step 210, the density for each pixel of the ideal print image is derived based on the density for each pixel of the negative image represented by the negative image data captured in step 178 and the print ideal characteristics. The density for each pixel of the ideal print image is obtained by converting the density value for each pixel of the negative image into a print density value using the print ideal characteristics. Hereinafter, data (standard copy image data of the present invention) representing the density (image feature amount for each pixel) for each pixel of the ideal print image obtained by the above processing is referred to as ideal print image data.
[0116]
In the next step 212, pixel data whose density value falls within a predetermined range on the negative image is extracted from the ideal print image data and the print image data captured in step 176, respectively. In place of the above, pixel data whose density value falls within a predetermined range is extracted from one of the print image data and ideal print image data, and pixel data corresponding to the pixel from which the data has been extracted is extracted. The image data may be extracted from the other image data, or the pixel data in which the density value on the print image and the density value on the ideal print image are each within a predetermined range are printed image data and ideal print image data. You may make it take out from each.
[0117]
The above-described extraction of pixel data is claimed in claim. 5 This corresponds to “selecting a plurality of pixels according to a predetermined criterion”. For example, when at least one of the various processing conditions of the printer processor 10 deviates from the processing conditions in the standard state, the density value represented by the data extracted from the print image data and the ideal print image data as described above is The ideal print image is different from the actual print image. If the print image data and the data extracted from the ideal print image data are plotted on the chart showing the print ideal characteristics, the image is extracted from the ideal print image data. The data is plotted on a straight line representing the ideal print characteristic indicated by the solid line in FIG. 7, whereas the data extracted from the print image data is, for example, on the straight line representing the current print characteristic indicated by the broken line in FIG. Plotted nearby.
[0118]
In step 214, according to the following equation (6), the density value D represented by the data extracted from the print image data is set as the difference z. _j (J in the expression (6) is a code attached to the extracted pixel data) and the density value DX represented by the data extracted from the ideal print image data _j The average value of the differences for each pixel is calculated.
[0119]
[Expression 2]

[0120]
Where n is the total number of extracted pixel data
Instead of the average value of the density value differences, a cumulative value of the density value differences may be calculated as the degree of difference z. The calculation of the difference z according to the equation (6) is as follows. 5 It corresponds to the calculation means described in. In the next step 216, an exposure amount correction value ΔE (exposure time correction value Δt) is calculated based on the value of the difference z calculated above. The processing after the next step 220 is the same as that in the second embodiment.
[0121]
As a result, the next time exposure processing is performed, the exposure time and the position of each filter of the color correction filter 28 are also corrected based on the newly set exposure amount correction value ΔE, and the corrected exposure amount E is used. Since the negative image is exposed onto the photographic paper 16, the density of the print image matches the density of the ideal print image regardless of the change in the state of the printer processor 10, as in the second embodiment. The negative image is exposed on the photographic paper 16 so that the hue of the portion with the maximum luminance is white.
[0122]
In the above description, the example of calculating the average value (or cumulative value) of the difference between the density values of the pixels extracted from the print image data and the ideal print image data has been described as the difference degree z. However, the present invention is not limited to this. Instead, an average value or cumulative value as a result of weighting the density value difference for each pixel may be calculated as the difference degree z. The setting of the weighting factor for each pixel can be performed as follows, for example.
[0123]
(1) Setting a weighting factor based on the density value of each pixel
As shown in FIG. 9, the entire range of density values that a pixel can take in print image data and ideal print image data (for example, if the pixel density is represented by 8-bit data, the range of density value = 0 to 255). The predetermined density difference range is divided into a plurality of density ranges (in FIG. 9, r density ranges from density range 1 to density range r as an example), and a weighting coefficient w is predetermined for each density range. . This weight coefficient is determined so that, for example, the weight of the density range corresponding to the average density value of the area corresponding to the person in the image is large, and the weight of the density range where the density is extremely high or extremely low is small. be able to. Then, it is determined which density range each pixel of the print image data (or ideal print image data) belongs to, and the weighting factor w determined for the density range to which each pixel belongs is set for each pixel. Set as weighting factor.
[0124]
(2) Setting a weighting factor based on the hue of each pixel
A color space defined by predetermined color coordinates is divided into a plurality of color regions (for example, in FIG. 10, a color defined by color coordinates having RG on the horizontal axis and GB on the vertical axis. The space is divided into 16 color areas a to p by line segments parallel to the vertical axis or the horizontal axis), and a weighting coefficient is determined in advance for each color area. This weighting factor increases the weight of the color area corresponding to the average hue of the area corresponding to the person in the image, for example, and the hue (for example, the sea or sky) existing in the area corresponding to the background portion in the image. The weight of the color area corresponding to blue, green of grass, etc.) can be determined to be small. Then, it is determined which color area each pixel hue of the print image data (or ideal print image data) belongs to, and the weighting factor w determined for the color area to which each pixel belongs is set for each pixel. Set as weighting factor.
[0125]
(3) Setting of weighting factor by cluster analysis
Based on the print image data (or ideal print image data), a density histogram or a histogram for the hue value (and saturation value) is obtained, and the obtained histogram is divided for each mountain. Are divided into groups corresponding to the divided peaks (cluster analysis). Next, the characteristics of each group (for example, the number of pixels belonging to each group, the frequency at the peak of the mountain corresponding to each group, a predetermined color space (for example, color coordinates with the hue value and saturation value on the vertical axis and the horizontal axis) The weight of each group is set so that the weight of the group estimated to correspond to the main part in the image increases according to the distance of each group from a predetermined reference value on the color space defined by Determine the coefficient. Then, a weighting factor is set for each pixel based on which group each pixel of the print image data (or ideal print image data) belongs to.
[0126]
The setting of the weighting factor described above is performed so that the weight of the pixel estimated to be related to the main part in the image is increased. 4 It corresponds to the calculation means described in. When the weighting coefficient is set for each pixel as described above, the above-described equation (5) or the following equation (7) (where j is the data of the pixel to be calculated for the difference z) The degree of difference z can be calculated according to (symbol attached to each).
[0127]
[Equation 3]

[0128]
Where n is the total number of pixels for which the difference z is to be calculated
In the above (1) to (3), it is possible not to use the data of pixels with extremely high or extremely low density or pixels with high saturation in calculating the degree of difference z. Needless to say.
[0129]
As described above, the comparison result of the density of pixels estimated to be related to the main part in the image (DX _j -D _j ) Is increased so that the processing conditions that have a high degree of influence on the image quality of the region corresponding to the main part of the image fluctuate. Since the degree of difference z increases and the exposure amount E is corrected so that the image quality of the area corresponding to the main part in the image is improved, the main part area which is particularly noticed in the evaluation of the image quality in the printed image. Can be made constant with high accuracy.
[0130]
[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described. Since the fourth embodiment has the same configuration as that of the first embodiment, the same reference numerals are given to the respective parts and description of the configuration is omitted, and the exposure amount correction processing according to the fourth embodiment will be described below. Will be described with reference to the flowchart of FIG.
[0131]
In the exposure correction processing according to the fourth embodiment, steps 230 to 236 are performed instead of steps 186 to 194 (see FIG. 4) of the exposure correction processing described in the first embodiment. In the fourth embodiment, steps 178 to 184 and steps 230 to 234 described in the first embodiment correspond to the calculation means of the present invention. In step 230, based on the density and print ideal characteristics of each pixel of the negative image represented by the negative image data captured in step 178, step 210 of the exposure amount correction process described in the third embodiment (see FIG. 8). In the same manner as described above, the ideal print image data is generated by deriving the density of each pixel of the ideal print image.
[0132]
In step 232, density histograms of the ideal print image and the actual print image are respectively created based on the ideal print image data generated above and the print image data captured in step 176. In the next step 234, the ideal print image is displayed. The difference z between the ideal print image and the actual print image is calculated based on the density histogram and the actual print image density histogram.
[0133]
In calculating the difference degree z, for example, the shape of the density histogram of the ideal print image is compared with the shape of the density histogram of the actual print image, and the difference in shape can be set as the difference degree z.
[0134]
Specifically, based on a value obtained by accumulating the absolute value of the frequency difference for each density class in both histograms over the entire histogram or within a predetermined density range (hereinafter referred to as histogram difference), When the histogram is moved in parallel to the frequency axis, the amount of parallel movement of the histogram that minimizes the histogram difference between the translated histogram and the other histogram is obtained. When this histogram difference is the minimum The parallel movement amount of the histogram may be set as the difference degree z. In addition, a part of the histograms is excluded according to a predetermined condition (for example, a density range until the cumulative frequency from the maximum value or minimum value of the density reaches a predetermined value) is compared, and the histogram shapes described above are compared. You may make it perform.
[0135]
Further, the image feature amount (for example, the density value) represented by the pixel data corresponding to both histograms may be compared, and the difference degree of the density value may be set as the difference degree z. Specifically, in both histograms, the location where the frequency is maximum or minimum, the location where the frequency peak (maximum or minimum) occurs, the cumulative frequency from the maximum value or minimum value of the concentration is set to a predetermined value. This can be realized by obtaining a cumulative value or an average value of differences of image feature amounts (for example, density values) represented by pixel data corresponding to the reaching location and setting this as the difference degree z. The calculation of the degree of difference z by the histogram described above is more specifically claimed. 6 It corresponds to the calculation means described in.
[0136]
As described above, even when the difference z is calculated using a histogram, data that adversely affects the value of the difference z (for example, data of pixels with extremely high or extremely low density) is removed. Since the degree z can be calculated, a value that accurately reflects variations in various processing conditions of the printer processor 10 is obtained as the degree of difference z. Note that the degree of difference z may be calculated for each component color based on, for example, the image feature amount for each component color of R, G, and B of the pixel used for calculating the difference degree z.
[0137]
In the next step 236, an exposure amount correction value ΔE is calculated based on the value of the difference z calculated in step 234. As a result, when the exposure process is performed next time, printing exposure of the negative image onto the photographic paper 16 is performed using the exposure amount E corrected in step 160 (see FIG. 3) with the newly set exposure amount correction value ΔE. Therefore, printing exposure of the negative image is performed so that the density of the print image matches the density of the ideal print image regardless of the change in the state of the printer processor 10.
[0138]
When the difference z is calculated for each component color in step 234, the color balance correction value ΔC is set using the difference z for each component color as the exposure amount correction value ΔE in step 236. Can do. In this case, the correction of the position of each filter of the color correction filter 28 based on the color balance correction value ΔC is also performed and the negative image is exposed to the photographic paper 16, so regardless of the change in the state of the printer processor 10. The negative image is printed and exposed so that the density and color balance of the print image matches the density and color balance of the ideal print image.
[0139]
[Fifth Embodiment]
Next, a fifth embodiment of the present invention will be described. Since the fifth embodiment has the same configuration as that of the first embodiment, the same reference numerals are given to the respective parts and description of the configuration will be omitted, and the exposure amount correction according to the fifth embodiment will be described below. The processing will be described with reference to the flowchart of FIG.
[0140]
In the exposure correction processing according to the fifth embodiment, steps 240 to 246 are performed instead of steps 186 to 194 (see FIG. 4) of the exposure correction processing described in the first embodiment. In the fifth embodiment, steps 178 to 184 and steps 240 to 246 described in the first embodiment correspond to the calculation means of the present invention.
[0141]
In step 240, based on the density and print ideal characteristics of each pixel of the negative image represented by the negative image data captured in step 178, step 210 of the exposure amount correction process described in the third embodiment (see FIG. 8). The ideal print image data is generated by deriving the density of each pixel of the ideal print image in the same manner as in step 230 (see FIG. 11) of the exposure correction process described in the fourth embodiment.
[0142]
In step 242, the ideal print image and the actual print image are each divided into a plurality of areas according to a predetermined standard, and a weighting coefficient is set for each area. This image division can be performed by applying any of the methods listed below, for example.
[0143]
(1) Image segmentation / weighting coefficient setting by person area extraction
Since the most noticeable part at the time of viewing in a portrait is a part corresponding to a person (especially a person's face), an area corresponding to the person is extracted as the main part in the image, and the weight of the area corresponding to the extracted person is extracted. However, a weighting factor is set for each region so that the weight is larger than the weights of the other regions. Extraction of an area corresponding to a person from an image may be performed for each of a print image and an ideal print image, but extraction of an area corresponding to a person for only one of the print image and the ideal print image and image division If the other image is divided into a plurality of regions based on the result of dividing the one image into a plurality of regions, the number of times of performing the process of extracting the region corresponding to the person can be reduced. preferable. Extraction of a region corresponding to a person from a print image or an ideal print image can be performed as follows, for example.
[0144]
[Example 1 of person area extraction method]
Based on the print image data (or ideal print image data), it is determined whether each pixel data constituting the print image (or ideal print image) is included in the skin color range on the color coordinates, An area where a cluster (group) of pixels determined to be within the skin color range is extracted from a print image (or an ideal print image) as an area corresponding to a person (Japanese Patent Laid-Open No. 52-156624, Japanese Patent Laid-Open Publication No. (See JP-A-52-156625, JP-A-53-12330, JP-A-53-145620, JP-A-53-145621, JP-A-53-145622, etc.).
[0145]
[Example 2 of person area extraction method]
Based on the print image data (or ideal print image data), a density histogram or a histogram for the hue value (and saturation value) is obtained, and the obtained histogram is divided for each mountain. Each pixel is divided into groups corresponding to the divided mountains (cluster analysis), and the print image (or ideal print image) is divided into a plurality of areas for each group. An area corresponding to the face of a person is estimated, and the estimated area is extracted from a print image (or ideal print image) (see Japanese Patent Laid-Open No. 4-346332).
[0146]
[Example 3 of person area extraction method]
Based on the print image data (or ideal print image data), a shape pattern specific to each part of the person existing in the print image (or ideal print image) (for example, head contour, face contour, internal structure of the face, Each of the shape patterns representing the contours of the torso and the like, and depending on the size and orientation of the detected shape pattern, and the positional relationship between the predetermined portion of the person represented by the detected shape pattern and the face of the person An area estimated to correspond to a human face is set. Further, another shape pattern different from the detected shape pattern is searched, the consistency of the previously set area as the face of the person is obtained, and the area corresponding to the face of the person is extracted (Japanese Patent Application No. 6-65850). No., Japanese Patent Application No.6-266598).
[0147]
(2) Image segmentation / weighting coefficient setting by background area extraction
An area corresponding to the background is extracted as a non-major part in the image, and the weight of the area corresponding to the extracted background is smaller than the weight of the other area (the image in the area other than the area corresponding to the background If it is determined that there is an area corresponding to the main part of (1), a weighting coefficient is set for each area. Extraction of the area corresponding to the background from the image may be performed for each of the print image and the ideal print image. However, the extraction of the area corresponding to the background for only one of the print image and the ideal print image is performed. If the image is divided and the other image is divided into a plurality of regions based on the result of dividing the one image into a plurality of regions, the number of times of executing the process of extracting the region corresponding to the background can be reduced. Therefore, it is preferable. Extraction of the area corresponding to the background from the print image or the ideal print image can be performed as follows, for example.
[0148]
[Example 1 of background region extraction method]
Based on the print image data (or ideal print image data), each pixel is included within a specific color range that clearly belongs to the background on the color coordinates (for example, sky, sea blue, lawn green, etc.) The region where the cluster (group) of pixels determined to be within the specific color range is determined as the region corresponding to the background and extracted.
[0149]
[Example 2 of background region extraction method]
Based on the print image data (or ideal print image data), the print image (or ideal print image) is divided into a plurality of areas in the same manner as in the example 2 of the person area extraction method described above, and each area is used as the background. Find the feature value of the corresponding area (ratio of straight line included in the outline, degree of line symmetry, number of irregularities, contact rate with the outer edge of the image, density contrast in the area, presence or absence of density change pattern in the area, etc.) Then, based on the obtained feature quantity, it is determined whether or not each region is a region corresponding to the background, and a region corresponding to the background is extracted (Japanese Patent Application No. 6-65850 and Japanese Patent Application No. 6-266598).
[0150]
(3) Image segmentation / weighting coefficient setting by cluster analysis
The image analysis by the cluster analysis may be performed for each of the print image and the ideal print image. However, the image analysis by the cluster analysis is performed for only one of the print image and the ideal print image, and the one image is determined. It is preferable to divide the other image into a plurality of regions based on the result of the division into a plurality of regions because the number of times of executing the cluster analysis process can be reduced. Image division by cluster analysis corresponds to a human face after an image is divided into a plurality of areas based on print image data (or ideal print image data) in the same manner as in Example 2 of the person area extraction method. Without estimating the area, each area depends on the characteristics of each area (for example, the area of each area, the contrast in each area, the distance of each area from a predetermined reference position on the screen (for example, the center of the screen, etc.)) A weighting factor is set for each.
[0151]
(4) Image division / weighting coefficient setting by fixed pattern
As shown in FIG. 13 as an example, a division pattern for dividing an image in a fixed manner (in FIG. 13, a division pattern for dividing an image into five regions a to e) is determined in advance. A weighting coefficient is determined in advance for each region divided by the division pattern. The weighting factor is, for example, based on an empirical rule that the main part of the image is likely to be located near the center of the screen, and the weighting factor of the region located near the center of the screen (region a in FIG. 13). It can be determined to be higher. Then, the print image and the ideal print image are each divided according to the division pattern.
[0152]
The method of dividing the image into a plurality of regions is not limited to the above. For example, an edge (contour line) in the image is detected by, for example, differentiation of density values, and a plurality of images are based on the detected contour line. You may make it divide | segment into this area | region. The setting of the weighting coefficient by each method described above is performed so that the weight of the region estimated to be related to the main part in the image is increased. 4 It corresponds to the calculation means described in.
[0153]
When the image division and the weighting factor are set as described above, in the next step 244, the image feature amount is calculated for each area of the print image and the ideal print image. As the image feature amount, for example, the average density for each area, the maximum or minimum value of density, the intermediate value of density, the density value at the peak of the density histogram for each area, the maximum density in the density histogram for each area A density value or the like when the cumulative frequency from the value or the minimum value is a predetermined value can be applied.
[0154]
In the next step 246, the image feature amount obtained for each area of the print image and the ideal print image is weighted by the weighting coefficient set for each area in step 242, and the degree of difference is calculated using the weighted value. z is calculated. The dissimilarity z in this case can be calculated according to the following formula (8) or (9), for example.
[0155]
[Expression 4]

[0156]
Where s is the number of regions, TX _j Is the image feature amount of region j of the ideal print image, T _j Is the image feature quantity of area j of the print image, w _j Is the weighting factor for region j. The above-mentioned image division and difference calculation are claimed in the claims. 7 It corresponds to the calculation means described in. Note that the degree of difference z may be calculated for each component color using the image feature amount for each component color of R, G, and B in each region.
[0157]
In the next step 248, the exposure amount correction value ΔE is calculated based on the value of the difference z calculated in step 246. Thus, the next time exposure processing is performed, the exposure amount E is corrected based on the newly set exposure amount correction value ΔE, and the negative image is exposed onto the photographic paper 16 using the corrected exposure amount E. Therefore, the negative image is exposed on the photographic paper 16 so that the density of the print image matches the density of the ideal print image regardless of the change in the state of the printer processor 10.
[0158]
In the above description, the comparison result (TX) of the image feature amount of the region estimated to be related to the main part in the image _j -T _j Since the weighting is performed so that the weight of () becomes larger, if the processing condition changes with a high degree of influence on the image quality of the area corresponding to the main part of the image, Since the exposure amount E is corrected so that z is increased and the image quality of the region corresponding to the main portion in the image is improved, the image quality of the main portion region that is particularly noted in the image quality evaluation of the print image. Can be made constant with high accuracy.
[0159]
If the difference z is calculated for each component color in step 246, the color balance correction value ΔC is set using the difference z for each component color as the exposure amount correction value ΔE in step 248. Can do. In this case, the correction of the position of each filter of the color correction filter 28 based on the color balance correction value ΔC is also performed and the negative image is exposed to the photographic paper 16, so regardless of the change in the state of the printer processor 10. The negative image is printed and exposed so that the density and color balance of the print image matches the density and color balance of the ideal print image.
[0160]
[Sixth Embodiment]
Next, a sixth embodiment of the present invention will be described. Since the sixth embodiment has the same configuration as that of the first embodiment, the same reference numerals are given to the respective parts, and the description of the configuration is omitted. Hereinafter, the ideal print image estimation according to the sixth embodiment will be described. The processing will be described with reference to the flowchart of FIG.
[0161]
This ideal print image estimation process is executed when the leading end portion of the photographic paper 16 on which an image is exposed and recorded by the exposure process is discharged from the drying unit 72, as in the exposure amount correction process in each of the embodiments described above. In this ideal print image estimation process, as is clear from FIG. 14, after performing steps 170 to 210 of the exposure amount correction process (see FIG. 8) described in the third embodiment, the determination of step 300 is performed. Steps 170 to 210 are repeated until the determination in step 300 is affirmed.
[0162]
However, in the ideal print image estimation process, the captured print image data is stored in the storage means 94E or the like in step 176, and after the ideal print image data is obtained in step 210, the ideal print image data is stored in the storage means 94E or the like. Remember. As a result, the print image data and the ideal print image data are stored for all the images on which the photographic paper 16 has been exposed. The steps 178 to 210 of the ideal print image estimation process are as follows. 0 This corresponds to the estimation means described in 1.
[0163]
Next, image display / exposure amount correction processing according to the sixth embodiment will be described with reference to the flowchart of FIG. In the sixth embodiment, when the operator wants to check the finish of the print image, check the status of the printer processor 10, etc., the operator instructs the display of the image on the display 100 via the keyboard 24 or the like. The image display / exposure amount correction process is executed by the CPU 94A of the control unit 94 when an instruction to display an image on the display 100 is given by the operator.
[0164]
In step 400, after displaying on the display a message requesting the operator to input information specifying an image to be displayed on the display 100, it is determined whether information specifying a print image to be displayed has been input by the operator. Wait until the determination is affirmed. An operator inputs information for specifying a print image to be displayed (for example, a frame number) or information indicating all image display for displaying all print images exposed on photographic paper. Thus, when an image to be displayed is designated, the determination in step 400 is affirmed, and the routine proceeds to step 402.
[0165]
In step 402, the print image data, ideal print image data, and exposure amount data of the image designated by the operator are fetched from the storage means 94E, etc., and in step 404, the print image and ideal image of the designated image based on the fetched data. Print images are simultaneously displayed on the display 100. This step 402 is claimed in claim 1. 0 It corresponds to the display means. In the next step 406, after displaying on the display 100 a message requesting the operator to input the test result for the image displayed on the display 100, it is determined whether or not the test result has been input by the operator. Wait until affirmed.
[0166]
On the other hand, when the print image and the ideal print image of the designated image are simultaneously displayed on the display 100, the operator refers to and compares the displayed print image and the ideal print image (print images and ideal print images of a plurality of image frames). Is displayed, it is verified whether or not the printer processor 10 has deviated from the standard state by referring to and comparing the print image and the ideal print image of each image frame. When it is determined that any of the various processing conditions of the printer processor 10 deviates from the processing conditions in the standard state, information indicating that the exposure amount is corrected is input as a test result, Input a correction value for the exposure amount.
[0167]
Further, the operator refers to the print image displayed on the display 100 (when print images of a plurality of image frames and ideal print images are displayed, refer to the print images of each image frame one by one). Thus, it is verified whether or not the print result of the designated image is appropriate (for example, whether or not the density, color, etc. of each part of the print image is appropriate). When it is determined that the print result is also appropriate, information indicating that the test result is “all OK” is input. However, if there is an image with an improper print result, the test result is Information indicating that reprinting is performed is input, and a correction value for the exposure amount of the image to be reprinted is input.
[0168]
When any information is input from the operator as described above, the determination at step 406 is affirmed and the routine proceeds to step 408. In step 408, the verification result by the operator is determined. If the verification result is “all OK”, the process ends. If the verification result is “exposure correction”, step 410 is performed. Migrate to
[0169]
In step 410, for all the images currently displayed on the display 100, based on the print image data captured in step 402 and the correction value for the exposure amount input together with the test result, the exposure amount by the input correction value. A simulation image representing a print image when the image is corrected is generated. In the next step 412, the generated simulation image and ideal print image are simultaneously displayed on the display 100. In step 414, after displaying a message requesting input of the test result, it is determined whether or not the test result is input from the operator.
[0170]
On the other hand, the operator compares and refers to the displayed simulation image and the ideal print image, and based on whether the density, color, etc. of each part of both images match or substantially match, It is determined whether or not the amount correction value is appropriate. If it is not appropriate, the exposure value correction value is input again. If it is appropriate, information indicating that the test result is “OK” is input.
[0171]
In the next step 416, the test result by the operator is determined. If the exposure correction value is input again, the process returns to step 410 and steps 410 to 416 are repeated. If information indicating that the test result is “OK” is input, the process proceeds to step 418, where the exposure amount correction value finally input is actually fed back to the exposure amount calculation. Set as correction value ΔE.
[0172]
As described above, when the operator determines that any of the various processing conditions of the print processor 10 deviates from the processing conditions in the standard state, the change in the image quality of the print image due to the deviation of the processing conditions is corrected. Thus, the exposure correction value ΔE is set. The processing for correcting the exposure amount E based on the exposure amount correction value ΔE during the step 418 and exposure (step 160 in FIG. 3) is described in claim 1. 0 This corresponds to the correction means described in (1).
[0173]
In the next step 430, a message is displayed on the display 100 to confirm to the operator whether or not the verification result is “all OK” due to the exposure amount correction, and it is determined whether or not the operator has determined “all OK”. To do. If the determination is affirmative, the process ends. If the determination is negative (for example, if the operator determines that there is an image frame to be reprinted), the process returns to step 406 to input the verification result. Request again.
[0174]
In step 408, if the test result is “reprint”, the process proceeds to step 420. In step 420, for the image designated as the image to be reprinted, based on the print image data captured in step 402 and the correction value for the exposure amount input together with the test result (exposure amount correction value in the previous step 418). When ΔE is set, this correction value is also taken into account), and a simulation image representing a print image when the exposure amount is corrected by the input correction value is generated. In the next step 422, the generated simulation image is generated. (And an ideal print image) are simultaneously displayed on the display 100.
[0175]
In step 424, after displaying a message requesting input of the test result, it is determined whether or not the test result has been input by the operator. On the other hand, the operator refers to the displayed simulation image and determines whether or not the correction value of the exposure amount input previously is appropriate based on whether the density, color, etc. of each portion of the displayed simulation image is appropriate. To do. If it is not appropriate, the exposure value correction value is input again. If it is appropriate, information indicating that the test result is “OK” is input.
[0176]
In the next step 426, the verification result by the operator is determined, and when the exposure value correction value is input again, the process returns to step 410 and steps 420 to 426 are repeated. If information indicating that the test result is “OK” is input, the process proceeds to step 428, and the exposure value correction value finally input is actually used when reprinting is performed. The exposure amount correction value to be fed back to the calculation is set and stored, and information for identifying an image to be reprinted (for example, a frame number) is stored, and the process proceeds to step 430.
[0177]
As described above, in the sixth embodiment, the print image of the image designated by the operator and the ideal print image are displayed on the display 100 at the same time, so that the operator takes troublesome operations such as picking up the actual print and verifying it. By referring to the print image displayed on the display 100 without performing work, it is possible to test whether the print result of the designated image is appropriate, and to display the displayed print image and ideal print image. By referring to and comparing, it is possible to easily check whether or not the printer processor 10 is in the standard state.
[0178]
In addition, since the examination can be performed by referring to the image displayed on the display 100, for example, in a developing place where a plurality of photographic processing devices such as the printer processor 10 are installed, the print results of each photographic processing device, etc. Display (which may be one or more) is arranged at a predetermined location (for example, a location away from the location where the photo processing apparatus is installed), and the processing conditions of each photo processing apparatus are managed and printed. It is also possible to test the results intensively at the predetermined location.
[0179]
In the above embodiment, an example in which the CCD image sensor 86 is provided as the first reading means for reading the negative image and the CCD image scanner 76 is provided as the second reading means for reading the print image has been described. A negative image and a print image may be read by the image reading sensor. As an example, FIG. 16 shows a CCD image sensor 86 (claims). 8 The negative image and the print image are read by the image reading element described in FIG.
[0180]
In the configuration of FIG. 16, an optical fiber array 116 (guide means) composed of a number of optical fibers is provided so that light emitted from the light source 114 and reflected by the photographic paper 16 is incident on one end side. On the light incident side of the CCD image sensor 86, a mirror 118 is provided that is moved to a position indicated by a solid line in FIG. The other end side of the optical fiber array 116 is extended to the vicinity of the position where the mirror 118 is disposed.
[0181]
In a state where the mirror 118 is located at a position indicated by a solid line, the light distributed by the distributing prism 32 (light transmitted through the negative image) is incident on the CCD image sensor 86, and the negative image is read by the CCD image sensor 86. It is done. In the state where the mirror 118 is located at the position indicated by the broken line, the light emitted from the light source 114 and reflected by the print image of the photographic paper 16 is guided by the optical fiber array 116 to the position where the mirror 118 is disposed. The printed image is read by the CCD image sensor 86 by being reflected by 118 and entering the CCD image sensor 86.
[0182]
As described above, if the first reading unit and the second reading unit share the single image reading sensor (the CCD image sensor 86 in the above), the cost required for the reading unit can be reduced. . Instead of the optical fiber array 116, light may be guided by a mirror or the like.
[0183]
In the above description, the image feature amount of the ideal print image is calculated in the exposure amount correction processing that is executed when the photographic paper 16 reaches the arrangement position of the CCD image scanner 76. However, the present invention is not limited to this. Instead, in the exposure process (FIG. 3) or while the photographic paper 16 is being processed by the processor unit 64, the image feature amount of the ideal print image may be calculated and the calculation result stored. .
[0184]
Further, a CCD image sensor 86 (first reading means) for photometry of the negative image and a CCD image scanner 76 (second reading means) for photometry of the print image each divide the photometry target image into the same number of pixels. However, the resolution of the first reading unit and the second reading unit may be different. In this case, if the screen average density is used as the image feature amount, the negative image data from the first reading unit and the print image data from the second reading unit can be used as they are for the calculation of the screen average density. However, when any one of the various image feature amounts described in the second and subsequent embodiments is used as the image feature amount, a resolution conversion process or the like is performed on either the negative image data or the print image data. The image feature amount may be calculated after the number of pixels constituting the negative image data and the number of pixels constituting the print image data are matched.
[0185]
Further, as the first reading unit and the second reading unit, other image reading sensors such as a CCD line sensor and a MOS type sensor can be applied. The image reading element is not limited to an element that separates and reads an image for each component color, and an element that reads the gray level of each part of the image can also be applied. In this case, the dissimilarity z and the exposure amount correction value ΔE may be obtained by calculating an average value of each color and correcting the exposure amount for each color uniformly based on the calculated exposure amount correction value ΔE. The present invention includes such an embodiment.
[0186]
In the above description, the predetermined exposure amount e is set by the printer processor 10 adjusted to be in the standard state. _T The relationship between the negative density d when the negative image is exposed and the print density D (print ideal characteristic) is stored, and this print ideal characteristic is used as the exposure amount E when the negative image is actually exposed. According to this, the ideal print characteristics when the exposure is performed with the exposure amount e are obtained by performing parallel translation. However, the image feature amount (for example, density) of the negative image, the exposure amount, and the image feature amount of the print image ( For example, the relationship with the density) is stored as a three-dimensional map, and the density of the actual negative image and the image feature amount of the ideal print image corresponding to the exposure amount when the negative image is exposed are obtained from this map. It may be. Further, the above relationship is obtained and stored for each film type of the negative film 14, the film type of the negative film 14 set in the printer processor 10 is determined, and the relationship corresponding to the determined film type is used as an ideal. You may make it obtain | require the image feature-value of a print image.
[0187]
Further, in the above, every time processing is performed on one negative film 14, the exposure amount correction value ΔE is calculated using all images (negative image and print image) subjected to printing exposure from the negative film 14 to the printing paper 16. Although the calculation has been performed, the period for calculating the exposure correction value ΔE and the image used for the calculation of the exposure correction value ΔE are not limited to the above. For example, every time a fixed period elapses or a fixed number of negatives Every time a film is processed or every time a certain number of images are printed, all images that have been subjected to printing exposure after calculating the previous exposure amount correction value ΔE, or a certain number of images, or predetermined image features The exposure correction value ΔE may be calculated using an image in which the amount (for example, the average screen density) is within a predetermined range.
[0188]
Further, in the above description, the exposure amount E is calculated by the exposure amount correction value ΔE after the exposure amount E is obtained by the equation (1). However, the exposure amount correction value ΔE is incorporated into the exposure amount calculation formula to thereby perform exposure. The exposure amount correction based on the calculation of the amount and the value of the dissimilarity z may be performed simultaneously.
[0189]
Further, in the above, as an example of a method for calculating the exposure amount correction value ΔE from the difference degree z, a currently set exposure amount correction value ΔE is obtained by multiplying the difference degree z by a coefficient a. ₀ In the above example, the new exposure amount correction value ΔE is calculated by adding to (see the expression (4) of the first embodiment), but the present invention is not limited to this, and the difference calculated in the past The degree z (for example, the average value of the degree of difference z calculated for each print image printed from each negative image recorded on one negative film 14) is stored, for example, N-1 times before the present. The exposure amount correction value ΔE may be calculated based on a time-series change in the value of the difference z calculated in the N different differences z. An example of a formula for calculating the exposure correction value ΔE when N = 2 is shown in the following formula (10).
[0190]
ΔE = a × z (T) + b × (z (T) −z (T−1)) + ΔE ₀ …(Ten)
Where z (T): the degree of difference calculated this time
z (T-1): The previously calculated difference
ΔE ₀ : Exposure correction value currently set
a, b: coefficients (a> 0, b> 0)
In equation (10), the exposure correction value ΔE is adjusted according to the time-series change tendency of the difference z. That is, when the difference z (T) calculated this time is larger than the previously calculated difference z (T−1), it can be determined that the value of the difference z is increasing in time series. The exposure amount correction value ΔE is increased by b × (z (T) −z (T−1)) as compared with the case where the exposure amount correction value ΔE is calculated according to the equation (4). The exposure correction value ΔE can be set so that the value of z becomes smaller, that is, the follow-up performance of the exposure correction with respect to the change in the state of the printer processor 10 is improved. When the difference z (T) calculated this time is smaller than the previously calculated difference z (T-1), it can be determined that the value of the difference z is decreasing in time series. Since the exposure amount correction value ΔE is decreased by b × (z (T) −z (T−1)) as compared with the case where it is calculated according to the equation (4), the exposure amount is corrected excessively. This can be suppressed.
[0191]
Equation (10) estimates the time-series change of the difference z based on the difference z obtained by each of N calculations, and the exposure amount correction is performed so that the difference z calculated next time converges to zero. The value ΔE is obtained, which is a so-called prediction function. Various functions have been known as prediction functions, and any of various known functions may be used for calculating the exposure correction value ΔE, and an optimum function and algorithm are experimentally obtained and applied. That's fine.
[0192]
Further, in the above description, an example in which the present invention is applied to a case where the printer processor 10 copies a negative image onto the photographic paper 16 to create a normal size print has been described. However, the reduction is performed separately from the normal print creation. The present invention can also be applied to the case where an index print is created by copying an index print image in which a plurality of images are arranged in a matrix on the photographic paper 16. The index print is created by a sub-exposure unit incorporated in the printer processor 10 or an index printer provided separately from the printer processor 10. The normal print image is generated so that the normal print image matches the ideal print image. By controlling exposure at the time of exposure and controlling exposure when the index print image is exposed by the sub-exposure unit or the index printer so that the index print image matches the ideal print image, the same negative image can be obtained. It is possible to make the finished print (index density, color balance, etc.) of the normal print and the index print substantially the same.
[0193]
Furthermore, as described above, a method for exposing an image by irradiating the photographic paper 16 with light transmitted through the entire surface of the negative image recorded on the negative film 14 (so-called surface exposure) has been described as a method for copying the original image. However, the present invention is not limited to this, for example, a method in which an image is scanned and exposed by laser light modulated according to the original image, or an original image is displayed on a display means such as a liquid crystal panel or a CRT, A method of exposing an image with light emitted from the display means (so-called digital printing method) can be applied. The present invention also relates to a so-called electronic device in which an original image is exposed on a photosensitive drum, and the image formed on the photosensitive drum is transferred to a copying material such as plain paper or an OHP sheet, thereby copying the original image onto the copying material. It can also be applied to a photo-type copying machine.
[0194]
In the above description, an image recorded on the negative film 14 as an original image has been described as an example. However, the present invention is not limited to this. For example, an image recorded on plain paper or other materials, or information processing such as a computer. Image data output from the apparatus can be used as an original image. In addition to photosensitive materials such as photographic paper, plain paper, OHP sheets, and the like can also be applied as copying materials.
[0195]
As mentioned above, although embodiment of this invention was described, said embodiment contains the embodiment of the technical matter described below other than the embodiment of the technical matter described in the claim.
[0196]
(1) The storage means exposes the original image to the copy material with a predetermined exposure amount by the copying means in a standard state as the relationship between the image feature amount and exposure amount of the original image and the image feature amount of the standard copy image. The relationship between the density of the original image and the density of the copy image when the standard copy image is formed on the copy material is stored, and the calculation means determines whether the copy means is the original image when estimating the standard copy image. When the exposure amount at the time of copying matches the predetermined exposure amount, the standard copy image is estimated using the relationship stored in the storage means, and the copy means copies the original image If the exposure amount is different from the predetermined exposure amount, the copying means exposes the original image to the copying material with the exposure amount based on the relationship stored in the storage means, and the copying material is standard. The density of the original image when a copy image is formed Estimating a relationship between the concentration of shot images, using the estimated relationship copying apparatus according to claim 2, characterized in that the estimate of the standard copy image.
[0197]
According to the above, since the relationship between the density of the original image and the density of the copy image only needs to be stored for the predetermined exposure amount, the storage capacity necessary for storing the relationship can be reduced, and Cost can be reduced.
[0198]
【The invention's effect】
Claim 1 as described above , Contract Claim 5 To claims 7 , Claim 1 0 , Claim 1 1 And claim 1 2 Each of the inventions has an excellent effect that the image quality of a copied image can be made constant with high accuracy regardless of changes in various processing conditions.
[0199]
In addition to the above effects, the invention of claim 2 has an effect that it is possible to accurately estimate a standard copy image formed by a copying means in a standard state.
[0200]
Claim 3 In addition to the above-described effect, the invention has an effect that the reliability of the difference value can be improved.
[0201]
Claim 4 In addition to the above-described effect, the invention has an effect that the image quality of the main area of the copied image that is particularly noted in the image quality evaluation can be made constant with high accuracy.
[0202]
Claim 8 In addition to the above effects, the invention has an effect that the cost of the apparatus can be reduced.
[0203]
Claim 9 In addition to the above effects, the invention has an effect that the exposure amount can be corrected so that the copy image has an appropriate color balance.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a printer processor according to an embodiment.
FIG. 2 is a schematic diagram illustrating a configuration of an optical system of a printer unit, a photometry system that performs photometry of a negative image and a print image, a control unit, and the periphery thereof.
FIG. 3 is a flowchart showing an exposure process.
FIG. 4 is a flowchart showing exposure correction processing according to the first embodiment.
5A is an exposure amount-print density characteristic when a negative image having a predetermined density is used when the printer processor is in a standard state, FIG. 5B is an example of ideal print characteristics, and FIG. 5C is an ideal print. It is a diagram which shows each other example of a characteristic.
FIG. 6 is a flowchart showing exposure correction processing according to the second embodiment.
FIG. 7 is a diagram for explaining calculation of a degree of difference in the second embodiment.
FIG. 8 is a flowchart showing exposure correction processing according to the third embodiment.
FIG. 9 is a conceptual diagram illustrating an example of a plurality of density ranges used for setting a weighting factor for each pixel.
FIG. 10 is a conceptual diagram illustrating an example of a plurality of color regions used for setting a weighting coefficient for each pixel.
FIG. 11 is a flowchart showing exposure correction processing according to the fourth embodiment.
FIG. 12 is a flowchart showing exposure correction processing according to the fifth embodiment.
FIG. 13 is a conceptual diagram illustrating an example of a division pattern used for dividing an image into a plurality of regions.
FIG. 14 is a flowchart illustrating ideal print image estimation processing according to the sixth embodiment.
FIG. 15 is a flowchart illustrating image display / exposure amount correction processing according to the sixth embodiment;
FIG. 16 is a schematic diagram showing a configuration of a photometry system for performing photometry of a negative image and a print image by a single sensor.
[Explanation of symbols]
10 Printer processor
14 Negative film
16 photographic paper
24 keyboard
28 Color correction filter
36 Black shutter
76 CCD image scanner
86 CCD image sensor
94 Control unit
100 display

Claims (12)

First reading means for reading an original image;
Exposure amount calculation means for calculating an exposure amount when copying the original image onto a copy material based on first image data representing the original image obtained by reading by the first reading means ;
Copying means for copying the original image onto a copy material with the exposure amount calculated by the exposure amount calculation means, and forming a copy image on the copy material;
Second reading means for reading a copy image formed on a copy material by the copying means;
Before SL based on the exposure amount when the first image data and the copying means is copied the original image to the copying material, the copying means is a standard copy image to be formed on copy material if were standard conditions The standard copy image is derived by deriving image feature quantities or standard copy image data representing the standard copy image, and from the second image data representing the copy image obtained by reading by the second reading means. an image feature quantity of the copied image which is obtained, the image feature quantity of the standard copy image the derived, or an image feature quantity of the standard copied image obtained from the standard copy image data the derived, by comparing the previous SL a calculating means for calculating a degree of difference between the standard copy images and replicated images the estimated,
Correction means for correcting the exposure amount calculated by the exposure amount calculation means based on the degree of difference calculated by the calculation means;
Copier including. Image feature amount and exposure amount of the original image and image of the standard copy image when the original image is exposed to the copy material by the copying means in the standard state obtained in advance and the standard copy image is formed on the copy material A storage means for storing the relationship with the feature quantity;
The calculation means estimates a standard copy image based on the first image data, an exposure amount when the copy means copies the original image onto a copy material, and the relationship stored in the storage means. 2. A copying apparatus according to claim 1, wherein: The calculating means uses a plurality of image feature amounts of the copy image and the image feature amount of the standard copy image, and calculates the degree of difference by comparing each image feature amount of the copy image and the standard copy image for each corresponding feature amount. Do
2. A copying apparatus according to claim 1, wherein: The arithmetic means increases the weight of the comparison result of the image feature amount estimated to be related to the main portion in the image, and decreases the weight of the comparison result of the image feature amount estimated not to be related to the main portion in the image. As described above, the comparison result of the image feature amounts of the copy image and the standard copy image is weighted, and the degree of difference is calculated based on the weighted result.
4. A copying apparatus according to claim 3, wherein: The arithmetic means constitutes an image with an image feature amount for each pixel of the copy image represented by the second image data and an image feature amount for each pixel of the standard copy image represented by the standard copy image data. Calculate the degree of difference based on the comparison result for all pixels or each of a plurality of pixels selected according to a predetermined criterion
The copying apparatus according to claim 1, wherein the copying apparatus is characterized in that: The computing means obtains a histogram of the copy image from the second image data, obtains a histogram of the standard copy image from the standard copy image data, and computes the degree of difference based on the result of comparing the histograms. Alternatively, the degree of difference is calculated based on a result of comparing image feature amounts of corresponding pixels on the histograms of the second image data and the standard copy image data.
The copying apparatus according to claim 1, wherein the copying apparatus is characterized in that: The calculation means divides the copy image and the standard copy image into a plurality of regions according to a predetermined standard, calculates the image feature amount for each region, and corresponds the image feature amount of each region of the copy image and the standard copy image. The difference is calculated based on the comparison result for each area
The copying apparatus according to claim 1, wherein the copying apparatus is characterized in that: 2. The first reading unit and the second reading unit share a single image reading element for reading an image, and read an original image and a copy image by the image reading element, respectively. The copying apparatus according to claim 7. The second reading means separates and reads a copy image into a plurality of component colors,
The correction unit determines a pixel having the maximum luminance on the copy image based on the second image data obtained by reading by the second reading unit, and performs exposure so that the hue of the pixel is white. Correct the amount for each component color
The copying apparatus according to any one of claims 1 to 8, wherein the copying apparatus is characterized in that: First reading means for reading an original image;
Exposure amount calculating means for calculating an exposure amount when the original image is copied to a copy material, based on first image data representing the original image obtained by reading by the first reading means;
Copying means for copying the original image onto a copy material with the exposure amount calculated by the exposure amount calculation means, and forming a copy image on the copy material;
Second reading means for reading a copy image formed on a copy material by the copying means;
Based on the first image data and the exposure amount when the copying means copies the original image onto the copying material, the standard copying image formed on the copying material when the copying means is in a standard state Estimating means for estimating the standard copy image by deriving standard copy image data;
Display means for displaying a copy image read by the second reading means and a standard copy image estimated by the estimation means;
An input means for inputting an exposure correction value;
Correction means for correcting the exposure amount calculated by the exposure amount calculation means based on the exposure value correction value input via the input means;
Copier including. Scan the original image,
Based on the first image data representing the original image obtained by reading the original image, calculating an exposure amount when copying the original image to a copy material,
The original image is exposed to the copy material by the calculated exposure amount by a copying means, and a copy image is formed on the copy material,
While reading the copy image formed on the copy material by the copying means,
An image of a standard copy image formed on the copy material when the copy means is in a standard state based on the first image data and the exposure amount when the copy means copies the original image onto the copy material. The copy image obtained from the second image data representing the copy image obtained by estimating the standard copy image by deriving the standard copy image data representing the feature amount or the standard copy image and reading the copy image Are compared with the image feature amount of the derived standard copy image or the image feature amount of the standard copy image obtained from the derived standard copy image data. Calculate the degree of difference from the copied image,
Based on the calculated degree of difference, correct the exposure when copying the original image to the copy material.
Copy control method. Scan the original image,
Based on the first image data representing the original image obtained by reading the original image, calculating an exposure amount when copying the original image to a copy material,
The original image is exposed to the copy material by the calculated exposure amount by a copying means, and a copy image is formed on the copy material,
While reading the copy image formed on the copy material by the copying means,
Based on the first image data and the exposure amount when the copying means copies the original image onto the copying material, the standard copying image formed on the copying material when the copying means is in a standard state Estimating the standard copy image by deriving standard copy image data,
Displaying the read copy image and the estimated standard copy image;
The exposure value when the original image is copied to the copy material is corrected by the input exposure value correction value.
Copy control method.

Images