JPH071379B2 - Method for determining photoprint exposure - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a method for determining a photographic printing exposure amount.

(Technical background of the invention and its problems) In a color film image such as a negative film obtained by photographing a standard scene, LATD (total average transmission) of three primary colors of R (red), G (green) and B (blue) It is known as an empirical rule that the color indicated by (density) is almost constant. For this reason, the conventional photoprinter measures the LATD of the three primary colors of the negative to be printed,
A print is created by controlling the light amounts of the three primary colors that pass through the color film to be constant. Therefore, a print with good color balance can be obtained from a standard color film image.

However, for a color film image dominated by a specific color, such control by LATD is not always effective, and a print with poor color balance is likely to occur.

A color film image in a specific color is mainly caused by a color deviation of a subject, an influence of a light source of a type different from daylight (a different type of photographic light source), a change in color film over time, and the like. Photographic printing devices usually have different levels of color correction such as low-correction, norman correction, high-correction, etc., and as described above, effective means for color correction by manually selecting a color film image having a specific color. Is used as.

The low-correction and normal-correction give the exposure by determining the exposure amount of one color by using the proportional coefficient of 1.0 or less for the LATD of the three colors of the color film image and influencing the LATDs of the other two colors. It is a control method and is suitable as a color correcting means for a color ferria caused by the color deviation of the subject. However, the collection for shooting films of different light sources and time-lapse images of films does not work,
Finally, the color is deteriorated.

In addition, the high collection determines the exposure amount by using a proportional coefficient of 1.0 or more for the three-color LATD of the color film image, and exposes the result of integrating the entire print density to a neutral color. It is a control method and is suitable as a means for color correction of the influence of different photographic light sources on a color film image or a color film image that has changed over time.
However, the collection does not work for the color film image that causes the color ferria, and eventually the color ferria is strengthened.

Conventionally, various methods have been proposed for appropriately controlling colors in color prints, but they are still not sufficient, for example, Japanese Patent Laid-Open Nos. 52-156624 and 52-156625. In KAISHO 53-145620, etc., baking exposure is performed using an ellipsoid on three-dimensional or two-dimensional coordinates around the RGB three-color density or a combination thereof, or a photometric point included in the skin color area defined by the ellipse. A method for determining the quantity is described. In addition,
No. 53-12330 describes a method of reproducing a predetermined color on a color film (for example, skin color, sky blue, green, snow, etc.) into a desired characteristic color on color paper. In all of these methods, a specific object color is extracted, and the exposure amount is determined so that the extracted specific object color has the same color on the print. These methods require the extraction of the specific object color, but it is very difficult to accurately extract the specific object color.

Furthermore, Japanese Examined Patent Publication No. 59-29847 describes a method in which relatively strongly colored points are not used for determining the exposure amount. As a condition of a point used for color correction, when at least two of the three conditions of the following formula (1) are satisfied, the condition is used for color correction.

However, D _W = (D _R + D _G + D _B ) / 3, D _NW = (D _NR + D _NG + D _NB ) / 3 where D _B , D _G , D _R try to print The densities of the respective points of the color film, _DNB , _DNG , and _DNR indicate the average densities of the respective colors of the color film on which an average subject is photographed.

Thus, in the above formula (1), when only one of D _B , D _G , and D _{R has} a large density, the two formulas on the left side become negative. That is, there is a drawback that some of the blue, green, and red colors are unconditionally selected.

In this example, only a limited number of photometric points can be selected, which is insufficient for the purpose of removing the color ferria component color.

Furthermore, in Japanese Examined Patent Publication No. 56-15492, the screen is metered in predetermined areas to check whether one of the RBG3 primary colors is clearly exceeded, and if it is, the printing exposure amount is checked. It describes the methods that should not be used for decisions. The ratio (B / G, G / R, R / B) of each color is compared with the set value in order to check whether one of the three primary colors is exceeded. In this case, the color information is only found and the color information is not used. That is, there is a drawback that the side light spots (for example, fluorescent lamps, tungsten lamp light) based on different kinds of light sources or the side light spots (magenta color) based on the elapsed time of the film cannot be distinguished from the side light spots that generate color ferria. For example, in the case of a film shot with a tungsten lamp, the light source color data is mainly discarded and the complementary color points are used as printing information, and those colors are printed in a print close to a neutral color, so the tungsten lamp color is further strengthened. It has the drawback of Such a case frequently occurs not only for different light sources but also for light sources with low color temperature in the sunset or winter. Originally, these film images should be subjected to neutral gray correction mainly based on the light source color point and the color point with time.

Further, in JP-A-59-220760, the measurement point to be inspected for the thinnest point is compared with a limit value, and by considering whether or not the measurement value is used for color copying, the main hue of the underexposure negative is determined. A method of determining the exposure dose for copying aimed at improving discrimination and eliminating the dependency of film type is shown. However, no mention is made of improvements to the above-mentioned different light source film and aged film. Further, in order to compare the photometric point with the limit value, the distance of the color vector from the center is obtained for each point and is compared with the predetermined limit value of each color. Further, since the limit value is changed with the film density, there is a drawback that it takes a very long time to calculate. Furthermore, the thinnest point (that is, the mask density) including the periphery of the film is set as the origin of the color coordinates to eliminate the dependency of the film type. This method has a drawback in that there is a limit in distinguishing the main hues without considering the difference in sensitivity balance and the difference in gradation of layers.

(Object of the Invention) The present invention has been made under the circumstances as described above, and an object of the present invention is to prevent a print from a color film image or a temporal film image taken by a different light source other than daylight from being deteriorated. Another object of the present invention is to provide a method for determining a photographic printing exposure amount capable of obtaining a color print with high color quality without generation of color ferria.

(Summary of the Invention) The first invention is that the whole or a part of a color film image is separated into three colors for photometry, and photometry is performed, and the coordinates in color coordinates representing a predetermined color using the photometric data of each point. A point is obtained, and it is determined in advance by dividing it into a plurality of regions gp (p> = an integer of 2>) which are different from each other on the color coordinate and have different limit regions with respect to saturation, and which one of the regions on the color coordinate belongs to. Is determined for each photometric point, and the average value Dp of the photometric data included in the region is determined for each region.
The coefficient Kp for the area gp is set to be larger in the low saturation area on the color coordinates and smaller (including 0) in the higher saturation area in advance, and the average value Dp of the photometric data is multiplied by the coefficient Kp. It is characterized in that the exposure amount is determined using a so-called high-correction color correction coefficient based on the added value.

In the second invention, the whole or a part of the color film image is divided into three colors for photometry for a large number of points, and the photometric data of each point is used to determine at least coordinate points in color coordinates representing hue and saturation. It is determined in advance by dividing it into a plurality of regions gp (integers of P> = 2) having saturation points that differ depending on the hue as the limit region, and to which of the regions on the color coordinates it belongs. Is determined for each photometric point, the average value Dp of the photometric data contained in a predetermined area of the area is determined, and the exposure amount is determined from the average value Dp using a so-called high correction color correction coefficient, It is characterized by

(Embodiment of the Invention) In the present invention, as shown in FIG.
The area 1 containing a large amount of tungsten light and magenta is set, and the photometric points of the film image are discriminated between the inside and outside of the area 1 for arithmetic processing. Area 1 in FIG. 3
Shows an example of region setting for an area where there are many film images of fluorescent lighting, and since it is difficult to distinguish between fluorescent lighting and green grass, leaves, etc., a wide area is given to green G. . Further, in an area where there are few film images of fluorescent lamp illumination, an area 2 in which the green area is relatively narrow is set in order to remove the color ferria of the green G as shown in FIG.

FIG. 5 shows the area 1 or 2 set on such color coordinates.
On the other hand, the block configuration of the apparatus for realizing the present invention that classifies the photometric data of the actual film image to determine the exposure amount is shown, and the photometric data from the photometric system 10 and the area set in the memory etc. 1 or 2 area information 11 (for example,
The area number is set for each chromaticity point) is input to the area determining means 12 to determine which area each photometric point belongs to, and the processing of the photometric data outside and inside the area will be described later. The exposure amount determined by the calculation means 13 is input to the exposure system 14, and the film image is exposed. When the chromaticity of the photometric point is obtained, the area determining means 12 immediately determines the area to belong to based on the tabulated area information 11. As an example of this determination, the method disclosed in JP-A-57-208422 can be used. By thus dividing the color coordinates into areas and storing them as a memory table in advance, it is possible to immediately perform the area determination, which conventionally took time, and to set the color areas freely. it can. In particular, as will be described later, a plurality of settings can be made in the saturation direction. This makes it possible to perform detailed setting and analysis regarding hue and saturation.

Next, an example of the method of the present invention will be described with reference to the flowchart of FIG. Here, the area 1 on the color coordinates and the area outside thereof are stored in the memory as shown in FIG.

In the present invention, first, a film image is processed by a two-dimensional image sensor, a line sensor, or the like, and a plurality of pixels as shown in FIG.
Divide the screen with Sn and perform photometry according to the scanning line SL (Step S
1) Normalize the photometric value of each divided pixel (step S
2). This normalization is a process of correcting the difference in the characteristic curve depending on the film type, and converting the same color subject to have substantially the same chromaticity on the color coordinates even if the film type is different. As the normalizing means, the method described in JP-A-56-1039 can be used. By normalizing the photometric value, the same color coordinates can be used even if the film density and film type are different.
The photometry of each pixel Sn is performed for the three primary colors of RGB, the position where the photometric value of each color corresponds to on the color coordinates shown in FIG. 3 is calculated, and whether it is inside region 1 based on the stored region information. Or outside is determined (steps S3, S
4), the calculation of the characteristic value in each pixel is repeated until all photometry is completed (steps S5 and S6). Average density value Da of each pixel in area 1 and average density value Db of pixels outside area
And are calculated by the calculation means 13 including a microcomputer. In this way, the average density values Da of all the pixels within the area 1 and the average density value Db of all the pixels outside the area 1 obtained by the calculating means 13 are multiplied by the coefficients Ka and Kb, and (2 ) Is calculated and the density value Dj for the film image is calculated. Dj ＝ Ka ・ Daj ＋ Kb ・ Dbj (2) Ka ＋ Kb ＝ 1.0 One of j ＝ R, G, B Here, the photometric data inside region 1 Since it is mainly used for determining the exposure amount and the influence of the photometric data of the pixels outside the area 1 must be reduced, the coefficient Ka is in the range of 1.0 to 0.6 and the coefficient Kb is set in the range of 0.0 to 0.4. To do. The above formula (2) is a general formula for the density data, and it is necessary to obtain the RGB3 primary colors in practice.
The density values for these three primary colors are obtained as D _R , D _G , and D _B , respectively (step S7). If the hatched area in the pixel data in FIG. 6 indicates, for example, data inside the area 1, and the pixel without hatching indicates data outside the area 1, the average density value Da of the hatched area and The average density value Db of the areas other than the above is calculated for each of the three primary colors RGB. Db
Instead of using the out-of-region data as it is, it is also effective to convert it to another data (for example, the average value of RGB3 primary color average density values outside the region) and use it. When the average value of the three primary color densities outside the area is used for Db, the accuracy of the density value Dj is good even if the number included in the area 1 is small, and therefore there is an effect that the fluctuation of the print density is small. Coefficients Ka and Kb in this case
Is not limited to the above range. For example, a coefficient proportional to the number of data may be used.

The screen average density value Dj of the RGB three primary colors obtained in this way
For (D _R , D _G , D _B ), the calculation means 13 performs the calculation of the formula (3) or the formula (4), and the exposure control is performed by the exposure amount D _RO , D _GO , D _BO determined by the calculation. Means 14 will perform the exposure.

However, a _{D O = (a · D R} + b · D G + c · D B) / (a + b + c). Or The coefficients K _R , K _G , and K _{B in the} above equation (3) and the coefficients K11 to K33 in the above equation (4) are color correction coefficients, and 1.0 or a value close thereto is used. Further, a plurality of predetermined coefficient groups may be visually selected as usual, or may be determined by a collection level discriminant function f (Ni, MXi). The function f (Ni, MXi) is a discriminant function formula for discriminating between the high collection level and the normal collection level or the low collection level. In the function f, Ni represents the number of pixels in the area, MXi represents the maximum density in the area, and Ni and MXi in each area are the characteristic value calculation unit (S5) in each area, and the average density of each area is You can ask at the same time you ask. Discriminant function formulas are widely used as statistical methods. For example, it is described in detail in "Multivariate Analysis Method" (Nikka Giren Publishing Co., 1971). The classification at the collection level may be performed by performing a large classification according to the position on the color coordinates of the image, that is, the average density, the distribution of the number of pixels Ni, etc., and determining it by a functional expression defined for each classification. It is preferable that the above-mentioned general classification includes at least one of a subject group including at least tungsten light and a subject group including fluorescent light. In this way, the collection is selected (step S8), and the collection coefficient of the equation (3) or (4) is determined (step S9).
The exposure amounts D _RO , D _GO , and D _BO to be sent to the exposure control means 14 are obtained (step S10), and the final exposure amount is determined and then the exposure control is performed (steps S11 and S12). In the case of FIG. 4, the collection level may be fixed to an appropriate level without being changed.

By the way, in the above description, the area set on the color coordinates is divided into two areas and the average density of the data measured inside and outside this area is obtained for the sake of simplicity. However, as shown in FIG. It is preferable to divide the color coordinates into a large number of areas (3 or more) before use. For example, divided areas are set like g1 to g16, and characteristic values such as average density are calculated for each area. The metering data is in these areas g1 to g16
After deciding which one of them belongs by the region determining means 12, the average densities D1 to D16 and other characteristic values N1 for each color for each region are determined.
~ N16, NX1 ~ MX16, etc. Then, K1 to K16 are stored in memory as coefficients for each group area,
(5) Obtain the average density D for each of the three primary colors D = K1 ・ D1 ＋ K1 ・ D2 ＋ …… ＋ K15 ・ D15 + K16 ・ D16 ……… （5） In this case, K1 ＋ K2 …… ＋ K16 = 1.0 The value common to all colors is used. Of these coefficients, generally, the weight from the center of the color coordinates in FIG. 7 to the area closer to the average color of many film frames is increased. These coefficients can be determined by a statistical (for example, least squares arithmetic) method so that an optimum print can be obtained.

According to this, the coefficient values of the areas g1 and g8 are large, and the area g2.g
The coefficient values of 4, g5, g6, g7, g10, g13, g15, g16 are small. Furthermore, it is effective to classify into different color light source color film images or aged color film images and other color film images, and change the size of each coefficient according to the classification. In such a case, in the set of coefficients for the different light source color film image and the aged color film image, (g9, g1
The value of 0, g12, g13 becomes large, and in the group of coefficient of classification for other color film images, g3, g9, g10, g12,
G13.g14 is smaller, which allows high quality printing of color film images of all kinds.

In this method, instead of changing the color correction coefficient in the expressions (3) and (4), the photometric data is evaluated for hue and saturation on the color coordinates, and the degree of contribution to the exposure amount determination is changed by the coefficient. Therefore, it is possible to perform finer and more appropriate color control for each color than the conventional method.

Several kinds of coefficient groups may be given in advance, and one of them may be selected. The selection may be performed by visual recognition as in the past, or by a function (Ni, Mxi).

Further, as described in the method of using Dj in which the high saturation point is converted into another value in the expression (2), it is also effective to convert the average density of the high saturation area and use it in the expression (5).

Next, the effectiveness of the present invention will be described.

FIG. 9 compares the characteristics of the conventional exposure amount determination method based on LATD with the exposure amount determination method of the present invention (FIG. 9 (A) shows a conventional method).
The characteristics by the LATD method, FIG. 9 (B) shows the characteristics of the present invention.

Thus, for property comparison, multiple color film images (about 3000) were separated for proper printing by the conventional LATD method, with three color correction levels selected as follows. That is, a color film image of different light source, a color film image of discolored color are high collection (denoted by H), a standard color film image is normal collection (denoted by N), and a color film image emitting a color feria is a low collection (by L). Show)
And

Further, FIG. 9 uses the coordinates representing the colors in FIG. 2, that is, the two-dimensional color coordinates in which the horizontal axis represents the difference in photometric values R-G and the vertical axis represents the difference in photometric values GB. Further, the average density of each image (LATD and average density according to the present invention) is represented as a coordinate point, the distance between the coordinate points from the coordinate origin is obtained, and the average of the distances of a large number of images included in a certain hue is obtained. The values (vertical axis) are shown with respect to the hue angle interval of 10 ° (horizontal axis).

As shown in FIG. 9 (A), the color film image of H and the color film image of L are not separated, and the color film image of H printed in the Lowt collection has a very bad color print. I agree to become.
Further, it is shown that the printing of the H and L color film images is deteriorated when printing is performed with the intermediate normal collection.

On the other hand, FIG. 9 (B) showing the characteristics of the present invention is divided into color coordinates of a large number of areas as shown in FIG. 7 and statistically determined coefficients to obtain the average density obtained by the equation (5). The results are shown. Further, since the color ferria component is removed when obtaining the average density, the average densities of the L and N color film images are close to each other, indicating that the influence of the H color film is small. That is, it shows that the color ferria component can be well removed without including the photometric points of different light source colors.

This indicates that the N and L color correction images can be appropriately printed and only the H color film image can be printed while suppressing the deterioration of the print color with only the normal correction or the high correction. In particular, it is shown that the color ferria is not generated even when printed in the high collection, so that the N and L color film images can be appropriately printed, and the H color film image can be corrected.

FIG. 2 illustrates a typical color film image having the characteristics shown in FIG. 9. Color film images (color marks R, G, and B, respectively, which cause color ferria, are marked with marks. (Shown) and a color film image that has discolored over time (causing magenta color deviation.
(Indicated by a circle) and a color film image (fluorescent lamp, tungsten lamp light, indicated by a circle, indicated by a circle) taken under different light sources, the coordinate points of the average density in the LATD method and the present invention are shown.

And, the mark ○, the mark is the coordinate point of the average density in the LATD method, the arrow of the mark ○, the mark indicates the coordinate point of the average density in the present invention, the color film image of the mark is close to the origin in the present invention. This shows that the average density of the present invention is a color close to gray by removing the color ferria.

On the other hand, the photometric points of the color film image marked with ◯ are not completely excluded from the judgment as the color ferria component, but it is understood that the approach to gray is much smaller than that of the mark.

Next, the discrimination between the fluorescent lamp and the green will be described by using the characteristic values in the divided areas. For fluorescent lamps, N11 and N12 are large, N1, N8, N5, N3 and N2 are 0 or close to 0, similarly, MX11 and MX12 are large and MX1, MX8, MX5, MX3 and MX2 are 0 or small. The coefficients K11 and K12 in these fluorescent lamp regions have large values because exposure control is performed based on the light source color. In addition, there are many N14, N15 on the green, N1, N8, N5,
N3 and N2 are not 0, MX14 and MX15 are relatively small, MX1, MX8,
MX5, MX3, MX2 are larger, and ratios such as N14 / N11, N15 / N12 can be used. In addition, if the average density, its tint, the number of shades and highlights, and the tint are used, the discrimination accuracy is further improved. Coefficient K1 for such greens
4, K15 has a small value, and the coefficient K1 has a large value.
The above is that the hue angle of fluorescent lamps is generally smaller than that of grass green, that is, grass green is on the shadow side, fluorescent green is on the highlight side, and fluorescent lamps are gray. It is extremely low. Of course, it is possible to make the determination by using the logical expression of these relationships, but it is possible to make the determination by expressing the above function as a functional expression. That is, if the discriminant of the fluorescent lamp is V1 = f1 (Ni, MXi) and the discriminant of the green is V2 = f2 (Ni, MXi), and if V1 is larger than V2, the film of the fluorescent lamp is judged. , V2 is V1 or more, it is judged as a green film. Tungsten lamp light and yellow color ferria can be distinguished in the same way.
Formalin cabrinega and magenta color ferrias (azalea flowers, pink clothes, furniture, etc.) can be distinguished, and cloudy or shaded subjects and blue color ferrias (blue sky, sea, clothes, etc.)
Can be determined. A coefficient group given in advance may be selected based on these discrimination results. Alternatively, each coefficient may be automatically calculated and determined based on the determination result.

Further, FIG. 8 shows still another example of the present invention, in which plural kinds of area types on color coordinates as shown in FIG. 3, FIG. 4 and FIG. Every other time, the switching means 20 switches by the switching signal SW to selectively output one,
The determination with the photometric data from the photometric system 10 as described above in the area determination means 12 can be freely changed. In this way, a plurality of types of areas 21 to 23 are set in advance, and an arbitrary one is selected by the switching means 20 according to the preference of the operator or the like and given to the area determining means 12, so that printing exposure with a higher degree of freedom is possible. It becomes possible to make the decision.

In the above-described embodiment, the area on the color coordinates is displayed with the horizontal axis as RG and the vertical axis as GB, but other polar coordinates or hexagonal coordinates defined by the hue angle and saturation are displayed. It may be displayed in a coordinate system or may be a coordinate system in which a brightness or density axis is added. Further, in the above description, the photometry of the color film image is described as an example of determining the color region for the entire screen.
The color area may be determined for the photometric point only at the center position of the screen where there are many main subjects, and the photometric point to be used may be defined by the density or color difference from nearby points. The photometric area may be defined according to the importance of the shadow portion, the highlight portion, the main portion in the image, the background, or the like. Such a color region determination method is effective for fluorescent film photography and identification of a film including green such as grass and the like, and it is effective to use it properly depending on the purpose and the object type. The above is the case of printing on photographic paper from a photographic film, but the present invention can be used for various systems from a photographic original image, duplication to reproduction materials, reproduction,
Its effectiveness is not lost.

(Effects of the Invention) As described above, according to the present invention, the photometric data of the photometric points in the original image are evaluated and classified on the color coordinates, and the weighting coefficient that is added to the photometric data for each photometric point is assigned to the color coordinates. Do not use the photometric data of the photometric point that causes color ferria depending on whether it is changed according to the position above or the position of the photometric data that uses the same weighting coefficient according to the position on the color coordinate is used for the exposure determination, or to what extent To prevent color ferria completely, and by using a so-called high-correction color correction coefficient to prevent deterioration of prints of color film images taken under different light sources or aged color film images. It is now possible to easily make prints with high color quality even for shooting scenes.

[Brief description of drawings]

FIG. 1 is a flow chart showing the method of the present invention, FIG. 2 is a diagram of color coordinates showing the principle of the method of the present invention, FIG. 3 and FIG.
FIG. 5 is a diagram showing an example of setting a region on color coordinates of the present invention, FIG. 5 is a block diagram showing an example of a device for realizing the present invention, and FIG. 6 is a state of photometry of a film image in the present invention. FIG. 7, FIG. 7 is a diagram showing another example of setting the area on the color coordinates of the present invention, FIG. 8 is a block diagram showing an apparatus for realizing another method of the present invention, and FIG. 9 (A). Is a diagram showing the characteristics of the conventional LATD exposure, and FIG. 7B is a diagram showing the characteristics of the exposure of the present invention. 1, 2 ... area, 10 ... photometric system, 11, 21 to 23 ... area data, 12 ... determination means, 13 ... computing means, 14 ... exposure control means system, 20 ... switching means.

Claims (5)

[Claims] 1. A whole or a part of a color film image is separated into three colors at a large number of points to perform photometry, and coordinate points in color coordinates representing a predetermined color are obtained using the photometric data of each point, The color coordinates are divided into a plurality of areas gp (p> = integer of 2) that are different from each other in the saturation limit range, and which of the areas on the color coordinates belongs to each photometric point. The average value Dp of the photometric data included in the area is determined for each area.
The coefficient Kp for the area gp is set to be larger in the low saturation area on the color coordinates and smaller (including 0) in the higher saturation area in advance, and the average value Dp of the photometric data is multiplied by the coefficient Kp. The exposure amount is determined using a so-called high-correction color correction coefficient based on the added value. 2. The whole or a part of a color film image is divided into three colors for a large number of points, and photometry is performed, and at least coordinate points in color coordinates representing hue and saturation are obtained using the photometric data of each point, In advance, the color coordinates are divided into a plurality of areas gp (P is an integer of P> = 2) whose saturation points are different from each other depending on the hue, and are defined. Determine the photometric point, determine the average value Dp of the photometric data included in a predetermined area of the area, and determine the exposure amount from the average value Dp using a so-called high correction color correction coefficient, A method for determining the characteristic exposure amount for photo printing. 3. A low-saturation area including an origin whose saturation area is different depending on a hue on the color coordinates and a high-saturation area outside thereof are divided into two areas, and the coordinate point is the area. Is determined for each point, the average value Da of the photometric data of the inner area and the average value Db of the photometric data of the outer area are obtained, and the average value Da, the coefficient Ka of the Db Ka, Kb (1.0 ＞ ＝ Ka ＞ ＝ 0.6,0.4 ＞
= KB> 0.0 and Ka + Kb = 1.0), and D = Ka ・
The exposure amount is determined based on the value D obtained from Da + Kb · Db. The method for determining the exposure amount for photographic printing according to claim 2, wherein the exposure amount is determined. 4. A photometric point used for determining the exposure amount of at least predetermined red and blue regions on the color coordinates is a photometric point used for determining the exposure amount of another color, especially a predetermined yellow region including tungsten lamp light. Use a weighting factor smaller than the point, or
Alternatively, a method for determining the photographic printing exposure amount according to claim 2 or 3 is characterized in that it is defined as a small limit area with respect to the saturation direction on the color coordinates. 5. A photometric point used for determining the exposure amount of at least a predetermined red and blue region on the color coordinate is an exposure amount of a predetermined region containing another color, particularly a magenta color which is likely to change color with the passage of time. A weighting factor smaller than the photometric point used for the determination is used, or is set as a small limit region in the saturation direction on the color coordinates. The method for determining the exposure amount for photo printing described.