JP2009159388A - Document image processing program, document image processor and document image processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a user to easily discriminate a character from other image elements on an output image when executing halftoning processing of a source document having multi-level characters and the other image elements and outputting it. <P>SOLUTION: After separating the character information of source document data and the other image information and executing monochromation using a threshold only to the character information, the halftoning processing is executed. The user can adjust the threshold, and a preview image indicating the example of how the output image looks when using the adjusted threshold is displayed when adjusting the threshold. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a program, apparatus, and method for document image processing that outputs original document data including character information having multi-tone color values and other non-character image information by halftoning the original document data. About.

  Conventionally, when outputting original document data having multi-tone color values in an image output device such as a copying machine or a facsimile transmission / reception device, halftoning processing (area gradation processing) is performed on the original document data. ) Is given. In such an apparatus, in order to make the output image easy to see for the user, the density adjustment can be performed for each density area such as the low density portion and the high density portion in the input image, and an image formation suitable for the input image can be obtained. An apparatus has been proposed (see Patent Document 1).

  The image processing technique disclosed in Patent Document 1 is determined by the low density portion density set by the low density portion density setting means and the high density portion density set by the high density portion density setting means. This is a technique for obtaining output gradation data for input image data based on the output gradation for the input gradation.

JP-A-6-121168 (paragraph 0012)

  By the way, in the image processing technique of Patent Document 1, even if the density of an image can be adjusted, there is no means for allowing the user to confirm the density after adjustment of the output image in advance.

  Further, the image processing technique of Patent Document 1 uses raster image data as input image data. On the other hand, document data created by a general document processing application program on a computer includes character information (character code data) and other non-character image information (raster image data such as photographs and vectors such as graphics). Image data).

  In the case of document data including character information (character code data) as described above, in order to convert the density using the technique of Patent Document 1, the character information is rendered (drawn) into multi-tone raster image data, and then the multi-order. It is necessary to perform density conversion on the tone raster image data. Thereafter, halftone processing for print output is performed on the multi-tone raster image data subjected to density conversion.

  However, even though important information in a printed image by a facsimile or a copier is usually a character, according to the above-described conventional technology, the character is blurred by the halftoning process, and the character is transferred to another user. It is more difficult to distinguish from image elements (especially images of character backgrounds).

  Therefore, an object of the present invention is to output the original document data including character information having multi-tone color values and other non-character image information by performing halftoning processing on the original document data. The purpose is to make it easier to distinguish characters on an image from other image elements.

  Another object of the present invention is to allow a user to adjust and confirm the density of characters on an output image in advance.

  Furthermore, another object of the present invention is to enable the user to grasp what color the characters on the output image are on the original document.

  Document image processing for providing original document data including character information having multi-tone color values and other non-character image information by halftoning and outputting the original document data provided according to the first aspect of the present invention In a computer-readable document image processing program for causing a computer to execute the method, the document image processing method separates the character information and the non-character image information of the original document data; Adjusting the adjusted threshold value, converting the color value of the separated character information into two gradations using the adjusted threshold value, and converting the two-graded character information into the separated non-character image. And a step of generating a composite image by combining the information and a step of performing a halftoning process on the composite image.

  According to the document image program, the character information included in the original document data is separated from the non-character image information, and the multi-tone color value of the character information is divided into two gradations with a threshold value. The processed character information is halftoned. Even if the halftoning process is performed on the character information that has been converted into two gradations with the threshold value, there is no significant change in the visual appearance, so that “blurring” due to the halftoning process does not substantially occur. As a result, it is easy for the user to visually distinguish characters from other image elements on the output image.

  In one preferred embodiment, the step of adjusting the threshold value includes a step of displaying a preview screen for adjusting the threshold value, and a predetermined preview character image having a multi-tone color value in the preview screen. A two-tone preview character image formed by two gradations, a halftone preview non-character image representing a result of the halftoning process performed on a predetermined preview non-character image having multi-tone color values, and A step of displaying a threshold value changing operation unit that changes the threshold value by being operated, and a two-tone color value of the two-tone preview character image displayed in the preview screen is changed by the operation unit; And changing according to the threshold value.

  According to such an embodiment, on the preview screen for adjusting the threshold, the user changes the threshold, and as a result of the change, how the predetermined preview character image is two-graded, and Since it is possible to preview how a predetermined preview non-character image is displayed as a result of halftone processing, the user can predict the appearance of the output image of the original document and can easily set the threshold appropriately. is there.

  In the document image processing program according to the present invention, the document image processing method may further include a step of adding a cover sheet image to the composite image. The step of adding the cover sheet image includes the step of inputting cover sheet document data including at least character information having multi-tone color values, and the color value of the character information in the cover sheet document data is adjusted. A step of generating two gradations with a threshold value, a step of generating the cover sheet image using the two-graded character information, and a step of associating the generated cover sheet image with the synthesized image. .

  According to the above configuration, for example, when it is desired to add a cover sheet for facsimile transmission to the composite image, the character information of the cover sheet is also converted into two gradations with a threshold value. It is easy to distinguish information.

  The present invention also provides the above-described document image processing method and an apparatus for performing the document image processing method.

  Document image processing provided according to the second aspect of the present invention, wherein original document data including character information having multi-tone color values and other non-character image information is subjected to halftoning processing and output. In a computer-readable document image processing program for causing a computer to execute the method, the document image processing method separates the character information and the non-character image information of the original document data; and the separation A step of selecting one type of fill pattern from a predetermined plurality of types of two-tone fill patterns based on the color values of the character information, and replacing the color values of the character information with the selected fill patterns Generating a composite image by combining the replaced character information and the non-character image information, and the composite image And a step of performing halftoning on.

  According to the document image program, the character information in the original document data is separated from the non-character image information, the multi-tone color value of the character information is replaced with a certain two-tone fill pattern, and this 2 Character information having a gradation fill pattern as a color value is halftoned. Even if the halftone process is applied to the two-tone fill pattern of character information, there is no significant change in the visual appearance, so that “blurring” due to the halftoning process does not substantially occur. As a result, it is easy for the user to visually distinguish characters from other image elements on the output image. In addition, it is easier for the user to determine what color value the character information had on the original document (how many colors) from the fill pattern of the character information on the output image.

  In one preferred embodiment, the step of selecting the character information fill pattern includes a step of displaying a preview screen for changing the fill pattern, and a predetermined preview character having a multi-tone color value in the preview screen. A halftone representing the result of performing the halftoning process on a two-tone preview character image obtained by replacing the color value of an image with a corresponding fill pattern and a predetermined preview non-character image having a multi-tone color value A step of displaying a preview non-character image and a threshold value changing operation unit for changing a fill pattern selected by the user according to the color value; and the two gradations displayed in the preview screen Changing the fill pattern of the preview character image in response to the operation unit.

  According to such an embodiment, on the preview screen for changing the selected fill pattern, the user changes the selected fill pattern threshold, and as a result of the change, the user selects which predetermined preview character image In addition, it is possible to preview how the predetermined preview non-character image is displayed as a result of the halftone process, so that the user can predict the appearance of the output image of the original document, It is easy to optimize the selection of the fill pattern.

  In the document image processing program according to the present invention, the document image processing method may further include a step of adding a cover sheet image to the composite image. The step of adding the cover sheet image includes inputting cover sheet document data including at least character information having multi-tone color values, and according to the color value of the character information in the cover sheet document data. Selecting one type of fill pattern from the plurality of types of fill patterns, replacing the color value of the character information in the cover sheet document data with the selected fill pattern, and the replacement Generating the cover sheet image using the character information, and associating the generated cover sheet image with the composite image.

  According to the above configuration, for example, when it is desired to add a cover sheet for facsimile transmission to the composite image, the color value of the character information of the cover sheet is also replaced with the corresponding fill pattern. It is easy to distinguish the character information on the output image and to know the original color.

  The present invention also provides the above-described document image processing method and an apparatus for performing the document image processing method.

  According to the present invention, when original document data including character information having color values and other image information is output by performing halftoning processing on the original document data, the character on the output image is transferred to other users. It is easier to distinguish from image elements.

  Further, according to one preferred embodiment of the present invention, when original document data including character information having color values and other image information is subjected to halftoning processing and output, the user is prompted. It is easier to predict the appearance of the output image in advance.

  Furthermore, according to the second aspect of the present invention, when original document data including character information having color values and other image information is output by performing halftoning processing on the original document data, It is easier to grasp the color of characters included in the image in the original document.

  Embodiments of the present invention will be described below with reference to the drawings.

  There are many variations of the embodiments of the present invention. In the following, as an example, a facsimile transmission / reception function is realized on a PC installed in a general-purpose computer, for example, a personal computer (hereinafter referred to as “PC”). An embodiment implemented as an application program (hereinafter referred to as “PC-FAX”) will be described. The PC-FAX included in this embodiment inputs original document data having multi-tone (for example, full color or index color) color values created by an arbitrary document processing application on a PC, and The original document data is converted into halftone processed monochrome halftone raster image data suitable for facsimile transmission, and the halftone raster image data is transmitted to a facsimile transmission / reception device outside the PC via a telephone network or the Internet. It is configured to transmit over the network.

  FIG. 1 shows a block configuration of an embodiment of a document image processing apparatus according to the present invention implemented by PC-FAX.

  As shown in FIG. 1, a PC-FAX 1 as an example of a document image processing apparatus according to the present invention is a computer program executed on a PC 100. The PC-FAX 1 is a multi-gradation (for example, DTP software, spreadsheet software, web browser, graphic software, photo retouching software, accounting software, etc.) from an arbitrary document processing application program 10 executed on the PC 100. Character information (that is, character code data) having color values (full color or index color) and other non-character image information (raster image data such as photographs and / or vector image data such as graphics). Original halftone raster suitable for facri millimeter transmission, and halftoning processing is performed on the input original document data. Convert to image data and then the halftone raster image Data to the facsimile transceiver 60 outside PC 100, and transmits through the communication network (not shown), having the function of.

  The PC-FAX 1 includes a FAX printer driver 20 configured as one of printer drivers that can be called from the document processing application 10, and a FAX communicator 30 for communicating with an external FAX transmission / reception device 60. The FAX printer driver 20 includes a threshold setter 22, a data separator 24, and a half toner 26. The FAX communicator 30 includes a cover sheeter 32 and a transmitter 34.

  The threshold setter 22 of the FAX printer driver 20 adjusts a two-level gradation threshold (threshold for converting the color value of character information into two gradations) set in advance in the data separator 24 according to a user request ( Change) and reset the two-gradation threshold after adjustment (change) to the data separator 24. When the data separator 24 changes the two-gradation threshold value in this way, the appearance of the character information in the output image (combination of character information and non-character information) is changed by changing the two-gradation threshold value at the same time. A preview image of character information and non-character information for allowing the user to preview an example showing how it changes is displayed on a display screen (not shown) of the PC 100.

  A data separator 24 of the FAX printer driver 20 receives original document data from the document processing application program 10 and separates character information included in the original document data from other non-character image information. The data separator 24 performs the two-gradation processing only on the character information of the separated character information and non-character image information, using the two-gradation threshold set by the threshold setter 22. Thereby, the multi-tone color value of the character information is converted into a two-tone color value. By the two-gradation using this threshold value, the color value of the character information is not substantially affected by the halftoning process to be performed later (that is, the color values of the previous two gradations are not changed even after the halftoning process). Maintained so that “blurring” does not occur). The non-character image information is not subjected to the above two gradation processing. For each page of the original document data, the data separator 24 synthesizes the two-graded character information and the non-character image information of the input original document data, thereby converting the multi-gradation page image data. Generate.

  Further, the data separator 24 requests the renderer 50 included in the OS (operating system) 40 on the PC 100 to perform rendering (conversion to raster image data) of the generated multi-tone page image data. Then, the rendering result (multi-tone raster image data) of the multi-tone page image data returned from the renderer 50 is passed to the halftoner 26.

  The halftoner 26 performs halftoning processing (for example, error diffusion) on the received raster composite image data, and passes the resulting halftone raster composite image data to the FAX communicator 30.

  If there is a request from the user, the cover sheeter 32 of the FAX communicator 30 receives raster image data of a cover sheet for fax transmission prepared separately from the original document data in response to the request from the FAX printer driver 20. Is added as the first page to the raster composite image data corresponding to the original document data passed from. The transmitter 34 is connected to the destination FAX transmission / reception device 60 specified by the user, and the raster composite image data corresponding to the original document data described above, and the cover sheet (if it has been added). The raster image data is transmitted to the connected FAX transmission / reception device 60.

  Hereinafter, the operation of the PC-FAX 1 having the above configuration will be described in more detail.

  First, the operation of the threshold setter 22 of the FAX printer driver 20 will be described. The threshold setter 22 is activated when requested by the user.

  For example, in the document processing application program 10, when the user selects “Print” from the “File” menu or selects the “Print” icon on the toolbar, a general “Print” is displayed on the display screen of the PC 100. After displaying a dialog box (not shown), select “PC-FAX” from the “Printer Name” list in this “Print” dialog box, and then click the “Property” button to set the threshold value setter. 22 is activated.

  When activated, the threshold setter 22 displays a “PC-FAX property” dialog box 70 illustrated in FIG. 2 on the display screen of the PC 100.

  As shown in FIG. 2, a basic setting sheet 71 of the “PC-FAX property” dialog box 70 includes a “paper size” selection tool 72, a “paper orientation (vertical / horizontal)” selection tool 73, and an “image quality” selection. A tool 74 and a “character density” selection / preview tool 75 are arranged.

  In the “character density” selection / preview tool 75, a threshold value changing operation unit 76, an “original” preview image 77, and an “output result” preview image 78 are displayed. Here, the threshold value changing operation unit 76 is, for example, a slider bar, and changes the character density on the output image (in other words, the two-gradation threshold value) when operated by the user. It has become. The “original” preview image 77 is composed of a preview character image prepared in advance having multi-tone color values and a preview non-character image serving as a background having multi-tone color values ( This is a multi-tone image formed by superposition. In the example shown in FIG. 2, the preview character image is an image of A to J alphabet character strings having various colors, and the preview non-character image is an image representing a grayscale gradation. . On the other hand, the “output result” preview image 78 is a two-gradation obtained by two-gradation of the preview character image in the “original” preview image 77 with the two-gradation threshold value changed by the threshold value changing operation unit 76. The preview character image and the halftone preview non-character image that is the result of performing the halftoning process on the multi-preview non-character image in the “original” preview image 77 are similarly synthesized (superposed). It is a two-tone image.

  Therefore, when the user operates the threshold change operation unit 76 to change the two-gradation threshold, the “original” preview image 77 does not change, but the two-tone color of the preview character image in the “output result” preview image 78. Changes. The user can adjust the two-gradation threshold value using the threshold value changing operation unit 76 so that the appearance of the preview character image in the “output result” preview image 78 suits his / her preference.

  The “image quality” selection tool 74 selects one of four types of image quality: “draft” mode 74 a, “standard” mode 74 b, “high definition” mode 74 c, and “photo” mode 74 d as the output image quality. Has radio buttons. Only when the image quality other than the “photo” mode 74d is selected, the two-gradation processing of the character information using the threshold value by the data separator 24 is effective. Therefore, the threshold value can be changed by the threshold value changing operation unit 76 only when an image quality other than the “photo” mode 74d is selected.

  FIG. 3 exemplifies a change in the character color of the “output result” preview image 78 when the user changes the two-gradation threshold on the “PC-FAX property” dialog box 70 shown in FIG. It is explanatory drawing to do.

  As illustrated in FIG. 3, the “original” preview image 77 is always the same image. That is, in the “original” preview image 77, the background (preview non-character image) is a gradation image from white to black, and the colors of 10 characters A to J (preview character image) arranged on the background are From left to right, for example (which is difficult to understand because the attached drawings are not color), they are red, green, blue, light blue (cyan), purple (magenta), yellow (yellow), black, dark gray, light gray and white.

  On the other hand, the “output result” preview image 78 is always a monochrome image of two gradations of white and black, but the user can determine how the characters (preview character images) in the image are visible by the “image quality” selection tool 74. It changes according to the image quality selected in (1) and the darkness level (two gradation threshold) of the character selected by the threshold value changing operation unit 76. That is, when the “photo” mode 74d is selected as the image quality, the “output result” preview image 78 becomes an image as indicated by reference numeral 78a in FIG. The image 77 is displayed as an image obtained as a result of simply performing halftoning (for example, error diffusion) on the multi-tone background and characters of the image 77. Therefore, not only the background but also the characters are slightly blurred and it is difficult to distinguish the characters from the background.

  On the other hand, when an image quality other than the photo mode 74d is selected, the “output result” preview image 78 is displayed in accordance with the character darkness level (two gradation threshold) selected by the threshold value changing operation unit 76. For example, the image is displayed as indicated by reference numbers 78b, 78c or 78d. Reference numerals 78b, 78c and 78d respectively illustrate “output result” preview images 78 when the density level (two-gradation threshold) of the selected character is relatively low, medium and high. In the “output result” preview images of the reference numbers 78b, 78c, and 78d, the background is a result of simply performing halftoning (for example, error diffusion) on the multi-tone background of the “original” preview image 77. The character is the result of converting the color value of the multi-tone character of the “original” preview image 77 into two gradations using the two-gradation threshold value, and since it is simple white or black, it is easy to distinguish from the background. Although not shown separately in FIG. 3, an “output result” preview image is displayed depending on which of “draft” mode 74a, “standard” mode 74b, and “high definition” mode 74c is selected as the image quality. The resolution of 78 (roughness of dot of image) is different.

  Furthermore, when an image quality other than the photo mode 74 d is selected, the user can change (adjust) the character density level (two-gradation threshold) using the threshold value changing operation unit 76, and the “output result” preview image 78. The darkness of the character displayed on the screen is updated to the one that has two gradations again at the changed darkness level (two gradation threshold). Therefore, the user can predict the appearance of characters on the facsimile output image when the changed two-gradation threshold is used by viewing the “output result” preview image 78.

  After changing (adjusting) the character darkness level (two gradation threshold) on the “PC-FAX Property” dialog box 70 in this way, the user clicks the OK button on the “PC-FAX Property” dialog box 70. When 79 is clicked, the two-gradation threshold after the change is set.

  FIG. 4 is a flowchart of the process of the threshold setter 22 performed using the “PC-FAX property” dialog box 70 described above.

  As shown in FIG. 4, when the threshold setter 22 is activated, it reads multi-tone preview character image data (for example, a multi-tone raster image) from document resources that the threshold setter 22 has in advance (step 1). Hereinafter expressed as “S1”). The threshold setter 22 also reads multi-tone preview non-character image data (the format is, for example, a multi-tone raster image) that is the background from the document resource (S2). Then, the two image data are combined to generate the data of the “original” preview image 77 described above (S3).

  Next, the threshold setter 22 determines which of the “draft” mode 74a, the “standard” mode 74b, the “high definition” mode 74c, or the “photo” mode 74d is selected as the image quality (S4). ).

  In S4, when an image quality other than the “photo” mode 74d is selected (S4 / NO), the threshold setter 22 displays the position of the slider bar of the threshold changing operation unit 76 (the character selected by the user). A two-level gradation threshold value corresponding to (darkness level) is acquired and substituted for the variable THR (S5). Then, the threshold setter 22 subjects the multi-gradation preview character image data read in S1 to a two-gradation process using the value of the variable THR as a two-gradation threshold value, thereby obtaining the two-gradation preview character image data. Obtain (S6).

  Here, the two-gradation processing using the above threshold will be described with reference to FIG.

  As shown in FIG. 5, the color value (for example, brightness) of a multi-gradation character is 256 gradations, for example, 0 to 255 for each color component (for example, for each RGB component), and the two-gradation threshold value Is, for example, a case where it can be selected by adjusting the threshold value changing operation unit 76 in the range of 120 to 255. In the two-gradation processing, the color value of a multi-gradation character (such as an average value of RGB component values or a weighted average value) is compared with the selected two-gradation threshold value. As a result of the comparison, as shown in FIG. 5, if the multi-tone color value is less than the threshold value, the color value is converted to black (R = 0, G = 0, B = 0). If not, the color value is converted to white (R = 255, G = 255, B = 255).

  Reference is again made to FIG. The threshold setter 22 performs halftoning processing (for example, error diffusion method) on the multi-tone preview non-character image data read in S2 described above to obtain half-tone preview non-character image data (S7). Thereafter, the threshold setter 22 combines the two-tone preview character image data obtained in S6 and the halftone preview non-character image data obtained in S7 to obtain “output result” preview image data (S8). Thereafter, the control proceeds to S10.

  On the other hand, when the “photo” mode 74d is selected as the image quality in S4 (S4 / YES), the “original” preview image data obtained in S3 is subjected to a halftoning process (for example, an error diffusion method), “Output result” preview image data is obtained (S9). Thereafter, the control proceeds to S10.

  In S10, the “original” preview image data obtained in S3 and the “output result” preview image data obtained in S8 or S9 are displayed in the “PC-FAX property” dialog box 70 displayed on the display screen. The “original” preview image 77 and the “output result” preview image 78 are displayed.

  By the way, in the above processing flow, although the halftoning process is not performed on the two-tone preview character image data obtained in S6, it may be performed. However, even if a halftoning process is performed on a character image that has two gradations with a threshold value, the color value does not substantially change. Therefore, in the above processing flow, such halftoning processing is abbreviated.

  Next, an operation performed by a portion other than the threshold setter 22 of the PC-FAX 1 shown in FIG. 1, that is, an image process for original document data from the document processing application program 10 will be described in detail.

  FIG. 6 shows a data flow in image processing for original document data.

  In the image processing shown in FIG. 6, for example, when the user selects “Print” in the “File” menu or selects the “Print” icon on the toolbar in the document processing application program 10, the display of the PC 100 is performed. After a general “print” dialog box (not shown) is displayed on the screen, it is started by clicking “OK” in the “print” dialog box.

  Hereinafter, this image processing will be described with reference to FIGS. 6 and 1.

  When this image processing is started, first, the data separator 24 of the FAX printer driver 20 inputs original document data from the document processing application program 10. At this time, character information (character code data, which can have multi-tone color values) included in the original document data, and non-character image information (raster image data such as photographs and / or vector images such as graphics) Data, which can have multi-tone color values) are separated from each other and input to the data separator 24 (S21, S22). The original document data is separated for each page and input to the data separator 24.

  The data separator 22 uses the two-gradation threshold set in the data separator 22 only for the character information of the separated character information and non-character image information for each page of the input original document data. The two-gradation processing is performed, and two-gradation character information having a two-gradation color value (whether white or black) is generated (S23). The “set two-gradation threshold value” used here means that if the user has adjusted the two-gradation threshold value in the “PC-FAX property” dialog box 70 shown in FIG. , The adjusted two-gradation threshold, otherwise it is the default two-gradation threshold. Note that the data separator 22 does not perform two-gradation using the threshold as described above on the separated non-character image information.

  Next, for each page, the data separator 22 generates the generated two-gradation character information and the non-character image information obtained by separating the original document data (since the above-described two-gradation is not applied, the multi-gradation is performed. The page image data is generated (S24). Thereafter, the data separator 22 sends the generated page image data to a renderer 50 included in the OS 40 of the PC 100 to render the raster image data having a predetermined specification such as resolution and paper size suitable for the facsimile transmission protocol. Is requested (S25).

  When the original document data has a plurality of pages, the processes of S21 to S25 described above are repeated for those pages.

  The rendering result of the page image data of each page, that is, the multi-tone raster page image data having the predetermined specification is returned from the renderer 50 to the data separator 22 (S26). The data separator 22 passes the multi-tone raster page image data of each page received from the renderer 50 to the halftoner 26. The halftoner 26 performs halftoning processing (for example, error diffusion) on the received multi-tone raster page image data of each page to generate halftone raster page image data (S27). This halftoning process affects the color value of a non-character image having a multi-tone color value on the original document data. There is virtually no effect. That is, the color value of the two-tone character information does not substantially change before and after the halftoning process (“blurring” does not appear). Note that the above halftoning process is not necessarily limited to the error diffusion method.

  Thereafter, the halftoner 26 activates the FAX communicator 30 and passes the halftone raster page image data of each page to the FAX communicator 30. When the FAX communicator 30 is activated, a predetermined dialog box (not shown) is displayed on the screen. When a user requests attachment of a FAX cover sheet on the dialog box, the cover sheeter 32 of the FAX communicator 30 is displayed. to start. On the other hand, if the user does not request attachment of a FAX cover sheet on the dialog box, the cover sheeter 32 is not activated.

  When the cover sheeter 32 is activated, a predetermined dialog box (not shown) is displayed on the screen, and a user can select a desired dialog sheet from a plurality of cover sheet data set in the cover sheeter 32 in advance. Let them choose one. Each cover sheet data includes at least character information (character code data) (can have multi-tone color values), and usually also includes non-character information (can have multi-tone color values). . The cover sheeter 32 has the same modules as the data separator 24, halftoner 26, and renderer 50 described above (all not shown). Then, the cover sheeter 32 performs image processing substantially the same as that performed on the original document data described above on the cover sheet data selected by the user.

  That is, the cover sheeter 32 separately inputs the character information and non-character information of the selected cover sheet data, and then the above-described 2 is set only for the character information of the character information and the non-character information. Applying two gradations using a gradation threshold, then synthesizing the two gradations of character information and the original non-character information to create multi-gradation cover sheet data, The multi-tone cover sheet data is rendered to generate multi-tone raster cover sheet data, and then the multi-tone raster cover sheet data is subjected to a halftoning process (for example, error diffusion) to provide a half-tone cover. Generate sheet data. Also in this halftone cover sheet data, since the color value of the character information is previously made into two gradations with a threshold value, it is not substantially affected by the halftoning process (“blurring” does not appear).

  The cover theta 32 adds the halftone cover sheet data generated in this way to the first page of the page image data received from the FAX printer driver 20 (S29).

  Thereafter, when the transmitter 34 is connected to the FAX transmitting / receiving apparatus 60 of the destination designated by the user, and the cover sheet is added to the FAX transmitting / receiving apparatus 60 as described above, the page image data with the cover sheet is attached. If not, page image data without a cover sheet is transmitted. The FAX transmission / reception device 60 may not be a FAX transmission / reception dedicated machine, but may be an MFP (Multiple Function Peripheral Multifunctional Peripheral Device), a PC on which a facsimile transmission / reception program is installed, or the like.

  The FAX transmission / reception device 60 prints out the received cover sheet and page image data of each page. In the printed image, the character information is not affected by the halftoning process, so that the user can easily distinguish the character from other image elements in the printed output image.

  In the above-described embodiment, the multi-tone color value of the character information (character code data) included in the original document data is divided into two gradations by the threshold before the halftoning process is performed. As a result, the color value of the character information is not affected by the halftoning process and is not blurred after the halftoning process. For the same purpose, as another method, a method of replacing the multi-tone color value of the character information with a predetermined two-tone fill pattern can be adopted.

  FIG. 7 shows an example of a plurality of fill patterns employed in another embodiment of the present invention employing such a method.

  7A, 7B, and 7C, a plurality of types of two-tone fill patterns (patterns inside the constituent lines of the letter A in FIGS. 7A, 7B, and 7C) are stored in the FAX printer driver 20 in advance. Is set. Each fill pattern is composed of a combination of a white region and a black region having a sufficiently large area so as not to be substantially affected by the halftoning process. The data separator 24 shown in FIG. 1 replaces the color value of the character information with two thresholds with the threshold value in S23 shown in FIG. In accordance with the color value, one fill pattern is selected, and the color value is replaced with the selected fill pattern. For example, the fill pattern is selected according to the hue or brightness grasped from the color value of the character information. Thereby, the user can grasp the color (hue or brightness) of the character in the original document from the fill pattern of each character of the output image.

  In this embodiment, steps other than S23 shown in FIG. 6 may be the same as the processing already described with reference to FIG.

  Further, in this embodiment, the “PC-FAX property” dialog box 70 shown in FIG. 2 changes the two-gradation threshold and displays the resulting preview image, instead of displaying the resulting preview image color. It is also possible to change the fill pattern that is automatically selected according to the value and display a preview image of the result. In this case, in the control flow shown in FIG. 4, in S5, the correspondence between the color value and the fill pattern is changed in response to the operation of the change operation unit by the user, and in S6, the changed correspondence is changed. The two-tone preview character image is generated by replacing the color value of the preview character image with the corresponding fill pattern according to the relationship. Other steps may be the same as those already described.

  Thus, by converting the color value of the character information into a two-tone fill pattern corresponding to the color value before performing the halftoning process, the character on the output image is transferred from other image elements to the user. It is easy to distinguish, and it is also easy to grasp the color (hue or brightness) of the character in the original document from the character fill pattern of the output image.

  As mentioned above, although preferred embodiment of this invention was described, said embodiment is an illustration for description of this invention, and is not the meaning which limits the scope of the present invention only to said embodiment. The present invention can be implemented in various modes different from the above embodiments without departing from the scope of the present invention.

  For example, in the flow shown in FIG. 6, rendering is performed after the two-gradation processing (or fill pattern replacement processing) of the character information. Conversely, after rendering, the two gradations of the character information are performed. Processing (or fill pattern replacement processing) may be performed. Further, instead of using the OS renderer, the PC-FAX may have its own renderer, and the own renderer may be used.

FIG. 1 is a block diagram of an embodiment of an image processing apparatus according to the present invention. FIG. 2 is an explanatory diagram of the “PC-FAX property” dialog box. FIG. 3 is an explanatory diagram illustrating the change in the “output result” preview image due to the change in the two-gradation threshold. FIG. 4 is a flowchart of processing for changing the two-gradation threshold. FIG. 5 is an explanatory diagram showing an outline of a two-gradation process using a threshold value. FIG. 6 is an explanatory diagram showing a data flow in image processing for original document data from a document processing application program. FIG. 7 is an explanatory diagram illustrating character fill patterns according to another embodiment of the image processing apparatus according to the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... PC-FAX (image processing apparatus), 10 ... Document processing application program, 22 ... Threshold setter, 24 ... Data separator, 26 ... Half toner, 32 ... Cover sheeter, 60 ... FAX transmission / reception device, 70 ... "PC-FAX property "Dialog box"

Claims (10)

Computer readable for causing a computer to execute a document image processing method in which original document data including character information having multi-tone color values and other non-character image information is processed by halftone processing. In a document image processing program,
The document image processing method includes:
Separating the character information and the non-character image information of the original document data;
Adjusting a preset threshold;
Converting the color value of the separated character information into two gradations with the adjusted threshold;
Combining the two-graded character information with the separated non-character image information to generate a composite image;
Performing a halftoning process on the composite image;
A document image processing program comprising: Adjusting the threshold comprises:
Displaying a preview screen for threshold adjustment;
In the preview screen, a two-tone preview character image obtained by converting a predetermined preview character image having a multi-tone color value into two gradations with the threshold value, and a predetermined preview non-character having a multi-tone color value Displaying a halftone preview non-character image representing a result of performing the halftoning process on an image, and a threshold value changing operation unit for changing the threshold value by being operated by a user;
2. The document image processing according to claim 1, further comprising: changing a two-tone color value of the two-tone preview character image displayed in the preview screen in accordance with a threshold value changed by the operation unit. program. The document image processing method includes:
Adding a cover sheet image to the composite image, and adding the cover sheet image;
Inputting cover sheet document data including at least character information having multi-tone color values;
Converting the color value of the character information in the cover sheet document data into two gradations with the adjusted threshold;
Generating the cover sheet image using the two-graded character information;
Associating the generated cover sheet image with the composite image;
The document image processing program according to claim 1 or 2, further comprising: In a document image processing apparatus for outputting original document data including character information having multi-tone color values and other non-character image information by performing halftone processing on the original document data,
Means for separating the character information and the non-character image information of the original document data;
Means for adjusting a preset threshold;
Means for converting the color value of the separated character information into two gradations with the adjusted threshold;
Means for combining the two-graded character information with the separated non-character image information to generate a composite image;
Means for performing a halftoning process on the composite image;
A document image processing apparatus comprising: In a document image processing method for outputting original document data including character information having multi-tone color values and other non-character image information by performing halftone processing on the original document data,
Separating the character information and the non-character image information of the original document data;
Adjusting a preset threshold;
Converting the color value of the separated character information into two gradations with the adjusted threshold;
Combining the two-graded character information with the separated non-character image information to generate a composite image;
Performing a halftoning process on the composite image;
A document image processing method comprising: Computer readable for causing a computer to execute a document image processing method for outputting original document data including character information having multi-tone color values and other non-character image information by halftoning the original document data. In a document image processing program,
The document image processing method includes:
Separating the character information and the non-character image information of the original document data;
Selecting one type of fill pattern from a plurality of predetermined two-tone fill patterns based on the color values of the separated character information; and
Replacing the color value of the text information with the selected fill pattern;
Combining the replaced character information and the non-character image information to generate a composite image;
Performing a halftoning process on the composite image;
A document image processing program comprising: The step of selecting the character information fill pattern comprises:
Displaying a preview screen for changing the fill pattern; and
In the preview screen, a two-tone preview character image obtained by replacing the color value of a predetermined preview character image having a multi-tone color value with a corresponding fill pattern, and a predetermined color value having a multi-tone color value. A halftone preview non-character image representing the result of performing the halftoning process on the preview non-character image, and a threshold value changing operation unit for changing a fill pattern selected according to the color value by being operated by a user; A step of displaying
The document image processing program according to claim 6, further comprising: changing a fill pattern of the two-tone preview character image displayed in the preview screen in response to the operation unit. The document image processing method includes:
Adding a cover sheet image to the composite image, and adding the cover sheet image;
Inputting cover sheet document data including at least character information having multi-tone color values;
Selecting one type of fill pattern from the plurality of types of fill patterns according to the color value of the character information in the cover sheet document data;
Replacing the color value of the character information in the cover sheet document data with the selected fill pattern;
Generating the cover sheet image using the replaced character information;
Associating the generated cover sheet image with the composite image;
The document image processing program according to claim 6 or 7, further comprising: In a document image processing apparatus for outputting original document data including character information having multi-tone color values and other non-character image information by performing halftoning processing on the original document data,
Means for separating the character information and the non-character image information of the original document data;
Means for selecting one type of paint pattern from a plurality of predetermined two-tone paint patterns based on the color value of the separated character information;
Means for replacing the color value of the character information with the selected fill pattern;
Means for combining the replaced character information and the non-character image information to generate a composite image;
Means for performing a halftoning process on the composite image;
A document image processing method comprising: In a document image processing method of outputting original document data including character information having multi-tone color values and other non-character image information by halftoning the original document data,
Separating the character information and the non-character image information of the original document data;
Selecting one type of fill pattern from a plurality of predetermined two-tone fill patterns based on the color values of the separated character information; and
Replacing the color value of the text information with the selected fill pattern;
Combining the replaced character information and the non-character image information to generate a composite image;
Performing a halftoning process on the composite image;
A document image processing method comprising:

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