JP2006229537A - Color correcting device and color correcting program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color correcting device easily correcting the tint of an image arranged on a page having an arbitrary ground color into a favorite tint and a color correcting program which makes a computer operate as the color correcting device. <P>SOLUTION: The color correcting device is equipped with: a page acquisition section 651 which acquires a page where an image object is arranged; a recognition section 652 which recognizes a dominant color phase in a region (ground) excluding the image object; and a correction section 653 which corrects the color of the image object so that the phase of the color is close to the dominant color phase of the ground recognized by the recognition section 652. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a color correction apparatus that corrects the color of an image to a preferred color and a color correction program that causes a computer to operate as the color correction apparatus.

  Conventionally, in the field of printing, DTP (Desk Top Publishing) that performs editing using a computer has been widely applied. In DTP, an operator can edit characters and images in a printed material while confirming the image of the printed material on a display screen before actually performing printing or plate making. In DTP, software used when an operator edits characters and images is generally called DTP software. The DTP software generates page description data in which a page on which an image edited by an operator is arranged is expressed in a page description language. The page description data is converted into raster data that can be handled by an output device typified by a printer, an image setter, or the like by a so-called RIP (Raster Image Processor). The output device outputs an output image based on the raster data.

  By the way, with the widespread use of digital cameras, the use of captured images taken with digital cameras as printing images has been widely performed. In general, for example, the photographed image is generally whitish due to backlighting, or the skin color is tinted due to the effect of lighting in the photographed image of the person, or the lens. In many cases, there are various inconveniences such as a scratch on the photographed image due to the attached dust or the like. Here, since the photographed image obtained by the digital camera is obtained as electronic data, the editor can correct the above-described inconveniences in the photographed image on the data during the editing work by DTP. For such image correction, so-called retouching software is used. In recent years, by analyzing the color characteristics of an image, or by recognizing a person's face in an image or scratches in an image by pattern recognition, the gradation of an image is corrected to a desirable gradation, Retouching software having an auto setup function for automatically performing various correction processes such as correcting the skin color of the face to a preferable skin color or removing the scratch on the image is also known.

  Here, in DTP, when creating a page using a photographed image, it is often performed not only to place a photographed image on a white page but also to place a photographed image on a page having some background color. That is. However, when a photographed image that has undergone the correction process using the auto setup function is placed on a page having such a background color, each photographed image is corrected to a preferable color, but to humans. Often the inconvenience of not looking at the preferred shades occurs.

In view of this, a technique has been proposed in which the color of a captured image arranged on a page is analyzed and a background color is determined so that the captured image looks preferable (see, for example, Patent Document 1).
JP 2002-300363 A (page 4-8, FIG. 1)

  However, the technique disclosed in Patent Document 1 has a problem in that the background color is determined according to the color of the photographed image, so that the optionality of the background color is impaired. On the other hand, after deciding an arbitrary background color, without using the auto setup function described above, it is a very skillful operation for the operator to adjust the color of the photographed image while viewing it on the display screen. This is a heavy burden on the operator.

  In view of the above circumstances, the present invention operates a color correction apparatus that can easily correct the hue of an image arranged on a page having an arbitrary background color to a preferable hue, and a computer as the color correction apparatus. An object of the present invention is to provide a color correction program to be executed.

The color correction apparatus of the present invention that achieves the above object includes a page acquisition unit that acquires a page on which an image is arranged,
A recognizing unit for recognizing a dominant hue in an area excluding the image of the page acquired by the page acquiring unit;
And a correction unit that corrects the color of the image so that the hue of the color approaches the dominant hue.

  According to the color correction apparatus of the present invention, the dominant hue in the area excluding the image on the page, that is, the background of the page is recognized, and the hue of the color of the image on the page is automatically set to the dominant hue. To be close. By such processing in the color correction apparatus of the present invention, the uncomfortable feeling that the viewer feels about the image arranged on the page having the background color can be easily removed without depending on the experience of the skilled person. That is, according to the color correction apparatus of the present invention, the hue of an image arranged on a page having an arbitrary background color can be easily corrected to a preferable hue.

  Here, in the color correction apparatus according to the present invention, the “recognition unit distributes the color of each part in the region other than the image on the page to a predetermined plurality of hue ranges, and each hue range has its hue. The form of calculating the frequency indicating how much color is distributed to the range and recognizing the dominant hue based on the calculated frequency is a preferable form.

  According to this preferred embodiment of the color correction apparatus, not only when the area of the page except the image is a single-color area, this area may be an area having a plurality of colors such as patterns and gradations. The dominant hue in can be easily recognized.

  In the preferred embodiment of the color correction apparatus, “the recognizing unit recognizes a hue representing the hue range having the highest frequency among the plurality of predetermined hue ranges as the dominant hue. The form “is” is a typical form.

  In the color correction apparatus according to the present invention, a form that “when the correction unit corrects the color of the image, the highlight portion in the image maintains the color” is a preferable mode.

  According to this preferred embodiment of the color correction apparatus, it is possible to correct the color of the image while suppressing unnecessary coloring from being added to the highlight portion.

Moreover, the color correction program of the present invention that achieves the above object is incorporated in a computer, and on the computer,
A page acquisition unit for acquiring a page on which an image is arranged;
A recognizing unit for recognizing a dominant hue in an area excluding the image of the page acquired by the page acquiring unit;
And a correction unit configured to correct the color of the image so that the hue of the color approaches the dominant hue.

  According to the color correction program of the present invention, it is possible to easily realize a color correction apparatus that can easily correct the above-described color of an image arranged on a page having an arbitrary background color to a preferable color. Can do.

  Note that the color correction program of the present invention is only shown in its basic form here, but this is merely to avoid duplication, and the color correction program of the present invention includes each of the color correction apparatuses described above. Various forms corresponding to the form are included.

  As described above, according to the present invention, it is possible to easily correct a hue of an image arranged on a page having an arbitrary background color to a preferable hue.

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

  FIG. 1 is a diagram showing a printing system to which an embodiment of a color correction apparatus of the present invention is applied.

  The printing system 10 shown in FIG. 1 includes a workstation 100, three personal computers 210, 220, and 230, a back-end processor (BEP) 310, and a color printer 320.

  In each of the three personal computers 210, 220, and 230, for example, a natural image typified by a captured image captured by a digital camera is acquired as an image object to be arranged on the page. Further, in each of these three personal computers 210, 220, and 230, the acquired image object is arranged on an arbitrary ground and a page is generated. Here, the base may be filled with a single color, or may have a plurality of colors such as a pattern or gradation. This page is a so-called PDL (Page Description Language), in which the background and the image object are described so as to be distinguishable from each other, and is input to the workstation 100.

  In FIG. 1, three personal computers 210, 220, and 230 are shown as page generation sources, but these are only examples of page generation sources, and pages connected to the workstation 100. The generation source may be, for example, a large number of personal computers of four or more, a small number of personal computers of two or less, or a workstation equivalent to the workstation 100. Alternatively, a dedicated device for page creation other than a general-purpose computer may be used.

  Here, the natural image acquired as the image object corresponds to an example of an image according to the present invention.

  The workstation 100 first analyzes the color characteristics of the image object on the input page, or recognizes the face and scratches of a person in the image object by pattern recognition. Then, various correction processes such as correcting the tone of the image object to a preferable tone, correcting the skin color of a person's face to a preferable skin color, and removing the scratch on the image object are automatically performed. An auto setup process to be performed and a color correction process to correct the color of the image object on the page to a preferable color corresponding to the dominant hue on the background of the page are executed. In addition, in the image object and the background of this page, the color space and color reproduction range assumed for color expression when the image object and the background are created are different from the color space and color reproduction range of the color printer 320 shown in FIG. There are many. For this reason, the workstation 100 also executes color conversion processing in which the color space and color reproduction range of the input page image object and background are matched with the color space and color reproduction range of the color printer 320 described above. Then, based on the page that has undergone these processes, raster data for printing is generated by a so-called RIP (Raster Image Processor). Finally, the raster data for printing is compressed to reduce the communication amount, and is output to the color printer 320.

  The compressed raster data is expanded by the BEP 310 and passed to the color printer 320. Then, the color printer 320 executes page output based on the raster data.

  In FIG. 1, a color printer 320 is shown as an example of a page output destination. However, the color printer 320 may be an electrophotographic color printer or an inkjet color printer. It doesn't ask what the printing method is. FIG. 1 shows a print system including a color printer 320 as an example of a system to which an embodiment of the color correction apparatus of the present invention is applied. The embodiment of the color correction apparatus of the present invention is shown in FIG. The applied system is not limited to this, and may be a printing system including a printing machine, for example. Here, the description will be made on the assumption that the printing system 10 of FIG.

  In the print system 10 described above, the workstation 100 operates as an image processing system to be described later to which an embodiment of the color correction apparatus of the present invention is applied. Hereinafter, the workstation 100 will be described with attention.

  The workstation 100 has an appearance configuration, a main body device 110, an image display device 120 that displays an image on a display screen 120a according to an instruction from the main body device 110, and various information according to key operations on the main body device 110. And a mouse 140 for inputting an instruction corresponding to, for example, an icon or the like displayed at that position by designating an arbitrary position on the display screen 120a.

  Next, the internal configuration of the workstation 100 will be described.

  FIG. 2 is a hardware configuration diagram of the workstation shown in FIG.

  As shown in FIG. 2, inside the main body device 110, a CPU 111 that executes various programs, a main memory 112 that reads programs stored in the hard disk device 113 and develops them for execution by the CPU 111, A hard disk device 113 storing programs and data, a flexible disk (hereinafter referred to as FD) 420 is loaded, an FD drive 114 that accesses the loaded FD 420, a CD-ROM drive 115 that accesses the CD-ROM 410, An input interface 116 that is connected to the personal computers 210, 220, 230, etc. in FIG. 1 and receives pages from these devices, and an output interface 117 that is connected to the BEP 310 in FIG. Have been , And these various elements, further an image display device 120 shown in FIG. 1, a keyboard 130, and mouse 140 are connected to each other via a bus 150.

  Here, the CD-ROM 410 stores various programs for operating the workstation 100 as an image processing system to which an embodiment of the color correction apparatus of the present invention is applied. When the CD-ROM 410 storing these various programs is loaded into the CD-ROM drive 115, the program stored in the CD-ROM 410 is uploaded to the workstation 100 and written to the hard disk device 113. Thereby, the workstation 100 operates as an image processing system described below.

  FIG. 3 is a block diagram showing an image processing system to which an embodiment of the color correction apparatus of the present invention is applied.

  The image processing system 500 shown in FIG. 3 takes in a page for each job, and corrects the gradation and color of the image object on the page to a preferable gradation and color for each page, or damages the image object. The above auto setup process to erase, the above color correction process to correct the color of the image object to a preferred color according to the dominant hue on the background of the page, and the premise of color expression when creating the image object or background The above color conversion processing is performed to match the color space and color reproduction range thus made with the color space and color reproduction range of the color printer 320 of FIG. 1, raster data is generated based on the processed page, and the raster data Is compressed and output to the color printer 320 shown in FIG. The image processing system 500 includes an input unit 510, a RIP 520, a compression unit 530, an output unit 540, and a primer 600.

  The input unit 510 receives a page P for one job. Here, as shown in FIG. 3, each page P is configured by arranging an image object P2 on a base P1. The page P for one job received by the input unit 510 is delivered to the primer 600 unless an instruction is given to the RIP 520 directly from the operator.

  Various processes including the auto setup process, the color correction process, and the color conversion process described above are performed for each page on the page P for one job passed from the input unit 510 to the primer 600.

  The primer 600 includes a color management system (CMS) 610 that performs processing on page colors, and the above-described auto setup processing and color correction processing are executed in the color correction device 650 included in the CMS 610. The color conversion device 660 performs the above color conversion processing. In addition, the primer 600 performs other than color correction such as error check for data representing pages and imposition designation when a plurality of pages are arranged and output on one sheet in the color printer 320 of FIG. The other processing device 620 for executing various processes is also provided. In the other processing device 620, these various processes are executed in accordance with an instruction from the operator. The page P for one job that has undergone each of the above processes in each element of the primer 600 is passed to the RIP 520.

  When a page P for one job is passed from the primer 600 to the RIP 520, raster data of each page is generated in the RIP 520. Further, after the raster data is compressed by the compression unit 530, the output unit 540 Is output.

  On the other hand, when the operator gives an instruction to pass directly to the RIP 520, the page P for one job is passed from the input unit 510 to the RIP 520. Here, the RIP 520 in the present embodiment has a function of executing the color conversion process among a plurality of processes executed by the primer 600, and when the above instruction is issued from the operator. In the RIP 520, raster data is generated after the color conversion processing is performed on the page P for one job. The raster data is compressed by the compression unit 530 and then output from the output unit 540 in the same manner as the processing in the case of passing through the primer 600.

  Here, the color correction device 650 included in the CMS 610 of the primer 600 corresponds to an embodiment of the color correction device of the present invention. In the following, paying attention to the color correction program, which is an embodiment of the color correction program of the present invention, which causes the color correction device 650 and the workstation 100 shown in FIGS. 1 and 2 to operate as the color correction device 650. explain.

  First, the color correction program will be described.

  FIG. 4 is a conceptual diagram showing a CD-ROM in which an embodiment of the color correction program of the present invention is stored.

  A CD-ROM 410 shown in FIG. 4 stores a color correction program 700 that is an embodiment of the color correction program of the present invention.

  The color correction program 700 includes a page acquisition unit 710, a recognition unit 720, and a correction unit 730.

  Details of each part of the color correction program 700 will be described together with the operation of each part of the embodiment of the color correction apparatus of the present invention.

  FIG. 5 is a functional block diagram showing functions when the color correction program shown in FIG. 4 is installed in the workstation shown in FIGS. 1 and 2 and this workstation operates as an embodiment of the color correction apparatus of the present invention. It is.

  As described above, the color correction device 650 shown in FIG. 5 makes the color of the image object P2 on the input page P correspond to the dominant hue on the background P1 of the page P. A color correction process of correcting to a preferable color is executed, and a page acquisition unit 651, a recognition unit 652, and a correction unit 653 are provided. Here, the page acquisition unit 651, the recognition unit 652, and the correction unit 653 correspond to examples of the page acquisition unit, the recognition unit, and the correction unit according to the present invention, respectively.

  When the color correction program 700 shown in FIG. 4 is installed in the workstation 100 shown in FIGS. 1 and 2, the page acquisition unit 710 of the color correction program 700 constitutes the page acquisition unit 651 shown in FIG. 720 constitutes a recognition unit 652, and the correction unit 730 constitutes a correction unit 653.

  The page acquisition unit 651 acquires a page P for one job passed from the input unit 510 shown in FIG. 3 for each page. The page P acquired by the page acquisition unit 651 is transferred to the recognition unit 652 page by page.

  The recognizing unit 652 recognizes the dominant hue in the background of one page passed from the page acquisition unit 651.

  The correction unit 653 performs the auto setup process on the image object on the one page, and corrects the color of the image object so that the hue of the color approaches the dominant hue. . Further, during this correction, the color is maintained for the highlight portion in the image object, and it is possible to prevent the highlight portion from having an unnecessary color.

  Next, the flow of color correction processing executed in the color correction device 650 will be described. In the following description, each component shown in FIG. 3 and FIG.

  FIG. 6 is a flowchart showing the flow of color correction processing executed in the color correction apparatus shown in FIGS. 3 and 5.

  The color correction process shown in the flowchart of FIG. 6 starts when a page P for one job is sent to the page acquisition unit 651 of the color correction device 650. When the color correction process starts, first, one of the pages P for one job is received (step S100).

  Next, the dominant hue in the background of the one page is recognized in the recognition unit 652 of the color correction device 650 (step S200). The process of hue recognition performed by the recognition unit 652 will be described later.

  When the dominant hue in the background is recognized in the process of step S200, first, one of the image objects arranged on the one page is extracted (step S300). Then, the above auto setup process is executed on the extracted image object (step S400). Further, for the image object that has undergone the auto setup process, the color of the image object is recognized in the process of step S200 while maintaining the color of the highlight portion in the image object. Correction is made to approach the hue (step S500). When the color correction process in step S500 is completed, it is determined whether or not there is an unprocessed image object in the one page (step S600). If there is an unprocessed image object (No determination in step S600), the processes in steps S300 to S500 are executed for the next image object. The processes in steps S300 to S500 are repeated until it is determined in step 600 that there is no unprocessed image object (Yes determination in step S600).

  Further, if it is determined in step S600 that there is no unprocessed image object, it is next determined whether or not there is an unprocessed page in the page P for one job. Step S700). When there is an unprocessed page (No determination in step S700), the processes in steps S100 to S600 are executed for the next page. The processes in steps S100 to S600 are repeated until it is determined in step 700 that there is no unprocessed page (Yes determination in step S700). When the color correction processing for all pages for one job is completed in the processing up to step 700, the color correction processing shown in this flowchart is completed.

  Next, the details of the recognition of the dominant hue on the background of the page executed in step S200 in the flowchart of FIG. 6 will be described.

  FIG. 7 is a flowchart showing the flow of recognition of the dominant hue on the page background, which is executed in step S200 in the flowchart of FIG.

  When the process shown in this flowchart is started, an image object is deleted from one page acquired in the process of step S100 in the flowchart of FIG. 6, thereby acquiring the background of that one page (step S201). Here, at the time when the processing shown in this flowchart starts, the above one page is described in the above PDL, and the image object and the background can be distinguished from each other. The image object is deleted based on this PDL description. Then, the background remaining after the image object is deleted is roughly rasterized at a low resolution (step S202). Next, statistical processing is performed on the rough rasterized background color, and the following histogram is created (step S203).

  FIG. 8 is a diagram showing an example of the background color histogram created in step S203 in the flowchart of FIG.

  In the histogram H shown in FIG. 8, when the colors of a plurality of pixels constituting the background are assigned to the five hue ranges H1,..., H5, how many pixels are assigned to each hue range. It represents. In this histogram H, the horizontal axis represents hue, and the vertical axis represents frequency as an index indicating how much color is distributed. In the present embodiment, the base colors are five hues each having a central hue of five colors of red, magenta (RM), yellow / red (YR), yellow (Y), green (G), and blue (B). A histogram H is created by allocating to the ranges H1,..., H5.

  Returning to FIG. 7, the description will be continued.

  When the background color histogram H shown in FIG. 8 is created by the processing in step S203, the central hue in the hue range having the highest frequency among the five hue ranges H1,..., H5 of the histogram H (FIG. 8). In this example, YR) is recognized as the dominant hue in the background (step S204), and the process of recognizing the dominant hue in the background shown in this flowchart ends.

  According to the processing described with reference to FIGS. 6 and 7, for example, when the background is filled with a single color, the colors of all of the plurality of pixels constituting the background are the single color. The colors of all the pixels are distributed to the hue range corresponding to the single color among the above five hue ranges H1,..., H5. Then, the central hue of the assigned hue range is recognized as the dominant hue in the background. If the background has a plurality of colors such as patterns and gradations, the color of each pixel constituting the background is distributed to the five hue ranges H1,... The central hue of the hue range to which the most is assigned is recognized as the dominant hue in the background. As described above, according to the present embodiment, the dominant hue in the background can be easily recognized even if the background is not only a single color but also a plurality of colors. .

  As described above, in the color correction apparatus 650 of the present embodiment, the color of the image object on each page is applied to the page background by the color correction processing described with reference to FIGS. 6, 7, and 8. It is automatically corrected to the preferred color accordingly. In other words, according to the color conversion device 650 of the present embodiment, the hue of an image object arranged on a page having an arbitrary background color can be easily corrected to a preferable hue.

  In the above description, as an example of the recognition unit according to the present invention, the colors of each of a plurality of pixels constituting the background are allocated to five hue ranges, and the central hue in the hue range in which the pixel colors are most frequently distributed is Although the recognition unit 652 that recognizes the dominant hue in the background has been described, the present invention is not limited to this. For example, the colors of a plurality of pixels constituting the background are allocated to a number of hue ranges other than five. It may be a thing. In addition, the recognition unit of the present invention, for example, finely distributes the colors of each of the plurality of pixels constituting the background into a large number of hue ranges, and then one hue having a relatively high frequency such as the second or third. For example, the range may be determined, and the central hue of the one hue range may be recognized as the dominant hue. In addition, for example, after a hue range is determined, the recognizing unit of the present invention determines a hue that is perceived as a dominant hue for humans in addition to the central hue. It may be something that is recognized.

1 is a diagram illustrating a printing system to which an embodiment of a color correction apparatus of the present invention is applied. It is a hardware block diagram of the workstation shown in FIG. 1 is a block diagram showing an image processing system to which an embodiment of a color correction apparatus of the present invention is applied. It is a conceptual diagram which shows CD-ROM in which one Embodiment of the color correction program of this invention was memorize | stored. FIG. 5 is a functional block diagram showing functions when the color correction program shown in FIG. 4 is installed in the workstation shown in FIGS. 1 and 2 and this workstation operates as an embodiment of the color correction apparatus of the present invention. 6 is a flowchart showing a flow of color correction processing executed in the color correction apparatus shown in FIGS. 3 and 5. It is a flowchart which shows the flow of recognition of the dominant hue in the background of a page performed by step S200 in the flowchart of FIG. It is a figure which shows an example of the histogram of the base color created by step S203 in the flowchart of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Print system 100 Workstation 110 Main body apparatus 111 CPU
112 Main Memory 113 Hard Disk Device 114 FD Drive 115 CD-ROM Drive 116 Input Interface 117 Output Interface 120 Image Display Device 120a Display Screen 130 Keyboard 140 Mouse 150 Bus 210, 220, 230 Personal Computer 310 Back End Processor 320 Color Printer 410 CD- ROM
420 flexible disk 500 image processing system 510 input unit 520 RIP
530 Compression unit 540 Output unit 600 Primer 610 Color management system 620 Other processing device 650 Color correction device 651 Page acquisition unit 652 Recognition unit 653 Correction unit 660 Color conversion device 700 Color correction program 710 Page acquisition unit 720 Recognition unit 730 Correction unit

Claims (5)

A page acquisition unit for acquiring a page on which an image is arranged;
A recognizing unit for recognizing a dominant hue in an area excluding the image of the page acquired by the page acquiring unit;
A color correction apparatus comprising: a correction unit configured to correct the color of the image so that the hue of the color approaches the dominant hue.   Frequency at which the recognizing unit assigns colors of each part in the area other than the image on the page to each of a plurality of predetermined hue ranges, and how much color is assigned to the hue range for each hue range The color correction apparatus according to claim 1, wherein the dominant hue is recognized based on the calculated frequency.   3. The color correction according to claim 2, wherein the recognition unit recognizes a hue representing the hue range having the highest frequency among the plurality of predetermined hue ranges as the dominant hue. apparatus.   2. The color correction apparatus according to claim 1, wherein the correction unit maintains a color for a highlight portion in the image when correcting the color of the image. Embedded in a computer, on the computer,
A page acquisition unit for acquiring a page on which an image is arranged;
A recognizing unit for recognizing a dominant hue in an area excluding the image of the page acquired by the page acquiring unit;
A color correction program that constructs a correction unit that corrects the color of the image so that the hue of the color approaches the dominant hue.

Images