JP2005269200A - Image processor, image processing method, storage medium and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize same color reproduction between different output devices. <P>SOLUTION: An image processor applies color space compression to an input image and output the image to an output device (DEV2). The processor is provided with a color space compressing II part (216) for applying color space compression to sRGB data acquired by converting into a color space independent from the device into a color reproduction range of an output device (DEV1) of a kind different from the output device (DEV2), and a color space compressing III part (217) for applying color space compression to the sRGB data subjected to the color space compression by the compressing II part (216) into a color reproduction range of the output device (DEV2). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a color matching processing technique.

  Conventionally, various color matching processes have been performed in an apparatus having an image processing function such as a PC in order to realize appropriate color reproduction in an output device such as a printer. FIG. 1 shows a flow of a general color matching process in a PC.

  As shown in the figure, input RGB data is converted into XYZ data in a color space independent of a device by an input profile 101. Here, since the output device cannot express colors outside the color reproduction range, all the colors included in the data must be within the color reproduction range of the output device. Therefore, the output profile 103 performs color space compression processing on the XYZ data, further converts the color space independent of the device into CMYK data that is a color space dependent on the output device, and outputs the data to the output device.

  In order to express a color outside the device color reproduction range with a color within the device color reproduction range, it is necessary to perform color space compression at the expense of one or more of brightness, saturation, and hue. For this reason, it is difficult to provide a standard color space compression algorithm that gives optimum color space compression for all input images.

For this reason, the ICC (International Color Consortium)
・ Perceptual
・ Media-Relative Colormetric
・ Saturation
・ ICC-Absolute Colormetric
And providing a framework capable of switching the color space compression algorithm according to the application (for example, mapping while maintaining the hue while maintaining the hue as much as possible).

  In general, in the output profile (B2Ax tag) 103, a color space compression step (from a device-independent color space (a color space including outside the color reproduction range of the output device) to a device-independent color space (within the color reproduction range of the output device). And a faithful color reproduction step (a step of mapping from an output device independent color space (a color space within the color reproduction range of the output device) to an output device dependent color space). Color space compression processing is performed in steps (see 103 ′).

Conventionally, the color space compression step is processed according to a color space compression algorithm generated so as to correspond to the application based on the color reproduction range of the output device.
JP 2001-45310 A

  However, even if there is an output profile with a good color space compression algorithm, if the output profile is output to a different output device, the same color reproduction is caused by the difference in the color reproduction range of the device. There was a problem that could not be realized. On the other hand, as a method for performing the same color reproduction between different devices, for example, a method of color space compression to a color reproduction range that can be reproduced in common by a plurality of output devices is conceivable. It is necessary to match the output device with a narrow range, and the capability of each output device cannot be fully utilized.

  If you are not satisfied with the color reproduction by the output profile, you need to fine tune the parameters of the output profile, but the output profile of the specific output device obtained in this way can be used as it is for the output of a different output device. There was also a problem that the profile could not be reused.

  The present invention has been made in view of the above problems, and a first object thereof is to realize the same color reproduction between different output devices. Furthermore, a second object is to make it possible to reuse the output profile of one output device while realizing the same color reproduction between different output devices.

In order to achieve the above object, an image processing apparatus according to the present invention comprises the following arrangement. That is,
An image processing apparatus that compresses an input image in color space and outputs the compressed image to an output device,
First color space compression means for color space compressing the input image converted into a device-independent color space within a color reproduction range of an output device of a type different from the output device;
And second color space compression means for color space compressing the input image color space compressed by the first color space compression means within a color reproduction range of the output device.

  The same color reproduction is realized between different output devices, and the output profile can be reused.

  First, an outline of processing (processing in an output profile) of the image processing apparatus in each embodiment of the present invention will be described. FIG. 10 shows a basic concept of processing in the image processing apparatus (here, different output devices are DEV1 and DEV2, respectively, and the same color reproduction as DEV1 is realized in DEV2, which is a color space. The case where the input to the compression II is sRGB will be described).

  As shown in the figure, the processing in the image processing apparatus has three color space compression steps of color space compressions I to III. In color space compression I, colors outside the sRGB color reproduction range are displayed in the sRGB color reproduction range. Color space compression is performed to map to the surface or in the vicinity of the surface and to reproduce the color within the sRGB color reproduction range faithfully or as faithfully as possible. Further, in the color space compression II, based on the correspondence (details will be described later) between the sRGB value and the reference color (color output in DEV1), the color in the sRGB color reproduction range is within the DEV1 color reproduction range (reference color). Compress the color space within the reproduction range. In color space compression III, a color outside the output device color reproduction range (a color outside the DEV2 color reproduction range) is mapped to the surface of the output device color reproduction range or in the vicinity of the surface without changing the color as much as possible. In addition, color space compression is performed so that colors within the output device color reproduction range are reproduced faithfully or as faithfully as possible.

  Here, the correspondence relationship between the sRGB values and the reference colors in the color space compression II is obtained by printing out the reference colors for the sRGB values from the reference output device (DEV1) and measuring the colors. This is because the sRGB value is a value that can be converted into a PCS value such as XYZ or Lab, and the correspondence between the sRGB value and the reference color is an output in which the input color reproduction range is sRGB and the output color reproduction range is a reference. This is because it can be regarded as color space compression information limited to the color reproduction range of the device (DEV1).

  As described above, the output profile is color space compression I for color space compression of the input image to a color within the sRGB color reproduction range, and color for color space compression within the color reproduction range of DEV1 based on the color space compression information of DEV1. The color reproduction is the same as that of the reference output device (DEV1) by including the space compression II and the color space compression III for performing color reproduction compression on colors within the color reproduction range of DEV2, and having these functions in order. Can also be realized in other output devices (DEV2) (that is, the same color space compression (including fine adjustment within the color reproduction range) as that of the printer (DEV1) realizing desired color reproduction) It can be realized on the printer (DEV2)).

  As a method for acquiring the color space compression information of the output device (DEV1) that realizes the desired color reproduction, in each of the following embodiments, print output is performed by applying a defined color space such as sRGB or AdobeRGB. The case of using the color patch, the case of using the color patch printed from the RGB / CMYK color space of the ICC profile, and the case of using the output profile of the output device as the “reference”, respectively. I decided to.

  According to each method shown in the following embodiments, the color space compression information can be easily acquired. Therefore, the color space compression information of the plurality of output devices (DEV1) (the color space compression information of the output device serving as a reference) ) Can be easily stored as a color space compression DB in advance. If these pieces of information can be stored as a color space compression DB, the same color reproduction can be easily realized even if the information is output to different output devices simply by reading the color space compression DB. (That is, the output profile can be reused).

  In the following embodiments, the case where the output device (DEV1) serving as a reference and the other output device (DEV2) are printers will be described. However, the present invention is not limited to this, and an output device such as a monitor may be used. .

[First Embodiment]
As the first embodiment of the present invention, color space compression information (information indicating a correspondence relationship between a reference color and an sRGB value) created based on a color patch for a defined color space such as sRGB or AdobeRGB is used. A case where color space compression is performed will be described.

<Functional configuration of image processing apparatus>
2 shows a functional configuration of an output profile of the image processing apparatus according to the first embodiment of the present invention.

  In the figure, reference numeral 212 denotes an sRGB inside / outside determination unit, which converts input RGB data into a PCS value (XYZ, Lab, etc.) in a color space that does not depend on a device in the input profile 211, and then inputs it to the output profile 220. The sRGB inside / outside determination unit 212 determines whether the PCS value is within the sRGB color reproduction range. In the sRGB inside / outside determination unit (212), the input PCS value (D50 reference) is converted into an XYZ value (D50 reference), and then converted into an XYZ value (D65 reference) by Bradford conversion or the like as shown in Expression (1). After the conversion, determination is made based on whether or not the value of each channel to which the sRGB inverse matrix shown in Expression (2) is applied is within the range of 0.0 to 1.0 (Expression (2a), Expression (2b)). Does not affect range determination).

Reference numeral 213 denotes a color space compression I section, which maps colors outside the sRGB color reproduction range to the surface of the sRGB color reproduction range or in the vicinity of the surface, and reproduces colors within the sRGB color reproduction range as faithfully or as faithfully as possible. Color space compression is performed. FIG. 25 shows an outline (one example) of processing in the color space compression I section (213) on the Lab color space. Note that the color space used for the color space compression I need not be limited to Lab, and may be a color space such as Luv or JCH.
As shown in the figure, first, a point P0 on the achromatic color axis that is a target when color space compression is performed on the color P1 outside the sRGB color reproduction range is determined. Here, the target point P0 has the same brightness as the point P2 having the maximum saturation Cmax on the surface of the sRGB color reproduction range having the same hue as the color P1 outside the sRGB color reproduction range.

  Next, as shown in FIG. 26, the midpoint P1 ′ between the point P1 and the target point P0 is moved along the locus on the equal hue connecting the point P1 and the point P0, and the intersection point with the surface of the color reproduction range is obtained. Let point P3 after color space compression. At this time, for the movement of the point along the locus on the same hue, for example, in the sRGB inside / outside determination unit (212), the inside point of the point P0 and the point P1 is determined as the moving point P1 ′, and the color reproduction range is determined. If it is within the range, processing is performed so that the midpoint of the points P1 ′ and P1 is a new moving point, and if it is outside the color reproduction range, the midpoint of the points P0 and P1 ′ is the new moving point.

  Returning to FIG. A PCS-sRGB conversion unit 214 converts a PCS value that has been color space compressed within the sRGB color reproduction range into an XYZ value, and then converts it into an sRGB value.

  Reference numeral 216 denotes a color space compression II unit, and based on the correspondence between sRGB values and reference colors (details will be described later), the colors in the sRGB color reproduction range are within the color reproduction range of DEV1 (202) (within the reference color reproduction range). ) To perform color space compression. 215 is used in the color space compression II section (216) based on the color space compression information read from the color space compression DB (205) in which the relationship between sRGB values and reference colors (color space compression information) is stored. This is a white point / black point correction unit that performs white point / black point correction to create an LUT (lookup table).

  Reference numeral 217 denotes a color space compression part III, and the color outside the color reproduction range of DEV2 (207) (outside the output device color reproduction range) is moved to the surface of the output device color reproduction range or in the vicinity of the surface without changing the color as much as possible. A color space compression process is performed so as to map and faithfully reproduce colors within the output device color reproduction range as faithfully as possible. 218 is used in the color space compression III unit (217) based on the colorimetric value file read from the colorimetric value file (210) in which the relationship between the device color of DEV2 (207) and the PCS value is stored. The white point / black point correction unit performs white point / black point correction to generate the LUT used in the LUT and the faithful color reproduction unit (219).

  Reference numeral 219 denotes a faithful color reproduction unit that performs processing for converting the sRGB values after color space compression output from the color space compression unit III (217) into CMYK values.

<Flow of processing in image processing apparatus>
Next, the flow of processing in the output profile (220) will be described with reference to FIG.

  First, in step S1801, a color space compression II part (216) LUT is generated. To generate the LUT of the color space compression II part (216), first, the color space compression information is read from the color space compression DB (205) in which the relationship between the sRGB values and the reference color is stored, and the following equation (4) is applied. Then, white point / black point correction (215) is performed (at this time, the white point and black point in the color space compression DB (205) are used as the media white point and media black point before correction), and then sRGB This is done by storing the relationship between the value and the corrected PCS value in the 3D LUT. The reason why the input color space of the LUT of the color space compression II section (216) is left as sRGB is that the accuracy in the sRGB space can be maintained rather than using other color spaces such as Lab. is there.

In step S1802, an LUT used in the faithful color reproduction unit (219) is generated. The LUT used in the faithful color reproduction unit (219) reads the colorimetric value file (210) in which the relationship between the device color of DEV2 (207) and the PCS value is stored, and applies the above equation (4). After correcting the white point / black point (218) (at this time, using the white point and black point in the colorimetric value file (210) as the media white point and media black point before correction, the corrected media Based on the relationship between the device color of the DEV2 and the corrected PCS value based on the relationship between the device color reproduction range and the corrected PCS value based on the relationship between the corrected PCS value of DEV2 ( 207) is converted into the device color. Here, for calculating the device color of DEV2 for an arbitrary corrected PCS value, a method for optimizing the matrix model color masking coefficient by an iterative method or the like, or a color difference for a neighboring color of an arbitrary corrected PCS value as a parameter. Or the like can be used. If the relationship between the corrected PCS value and the calculated device color of DEV2 is stored in the 3D LUT, an LUT used in the faithful color reproduction unit (219) can be created.
The B2A0 tag 3D LUT is created using the LUT of the color space compression II part (216) and the LUT of the faithful color reproduction part (219) obtained by the above processing. Then, the following processing is performed for each PCS value corresponding to the lattice point of the 3D LUT.

  First, in step S1803, an input color (PCS value) is acquired, and in step S1804, the sRGB inside / outside determination unit (212) determines whether the sRGB color reproduction range is inside or outside.

  If it is determined that the PCS value is within the sRGB color reproduction range, the process advances to step S1805 to apply the color space compression I unit (213). Note that when the defined color space is XYZ or Lab, the input color space of the color space compression II (216) is XYZ or Lab, so that the processing of the color space compression I (213) can be omitted. .

  After the color space compression I part (213) is applied in step S1805, or if it is determined in step S1804 that the input PCS value is within the sRGB color reproduction range, the process proceeds to step S1806. In step S1806, in order to apply the LUT of the color space compression II section (216), the PCS values that fall within the sRGB color reproduction range are converted into sRGB values. Here, in the conversion (214) from the PCS value to the sRGB value, the PCS value (D50 standard) is converted into the XYZ value (D50 standard), and then the XYZ value (Brazford conversion as shown in the equation (1)) is performed. D65 standard), and further by converting from XYZ values (D65 standard) represented by the equations (2), (2a), and (2b) to sRGB values.

  In step S1807, the color space compression II part (216) LUT is applied. The application of the color space compression II part (216) is performed by tetrahedral interpolation of a 3D LUT or the like. As a result, the PCS value after LUT interpolation falls within the color reproduction range of the output device (DEV1) serving as a reference.

  Next, in step S1808, it is determined whether or not it is within the color reproduction range of the output device (DEV2). If it is determined that it is not within the color reproduction range, the process proceeds to step S1809 and the color space compression III part ( 217) is applied. In the color space compression part III (217), a color outside the output device color reproduction range is mapped to the surface of the output device color reproduction range or near the surface without changing the color as much as possible, and within the output device color reproduction range. Color space compression is performed so that colors are reproduced faithfully or as faithfully as possible.

The color space compression method in the color space compression part III (217) may be the same method as that shown in FIGS. 25 and 26 for mapping the surface of the output device color reproduction range, or may be a different color space compression method. . At this time, the output device color reproduction range inside / outside determination is performed using a corrected PCS value obtained by applying white point correction / black point correction (218) to the colorimetric value file (210). For example,
Red (C: 0%, M: 100%, Y: 100%, K: 0%)
Yellow (C: 0%, M: 0%, Y: 100%, K: 0%)
Green (C: 100%, M: 0%, Y: 100%, K: 0%)
Cyan (C: 100%, M: 0%, Y: 0%, K: 0%)
Blue (C: 100%, M: 100%, Y: 0%, K: 0%)
Magenta (C: 0%, M: 100%, Y: 0%, K: 0%)
White (C: 0%, M: 0%, Y: 0%, K: 0%)
Black (C: 100%, M: 100%, Y: 100%, K: 100%)
It is also possible to determine from approximation by a dodecahedron as shown in FIG. However, when there is a paste amount limitation for Black or the like, the corrected PCS value for the CMYK value after the paste amount limitation is used.

  After the color space compression III part (217) is applied in step S1809, or when it is determined that it is within the color reproduction range of the output device (DEV2), the process proceeds to step S1810 and the faithful color reproduction part (219). Apply the LUT to get the desired device color. Here, the LUT application of the faithful color reproduction unit (219) is performed by tetrahedral interpolation of the 3D LUT or the like.

  In step S1811, it is determined whether or not processing has been completed for all input colors. If it is determined that processing has not been completed, the process returns to step S1803. On the other hand, if it is determined that the process has been completed, the process ends.

  As described above, the B2A0 tag can be created by storing the device color obtained using each PCS value corresponding to the 3D LUT lattice point as an input color in the 3D LUT. The number of output channels of the 3D LUT is 3 when the data format of the output device is RGB, and 4 when the data format of the output device is CMYK.

<Generation method of color space compression DB>
Next, a method for creating a color space compression DB storing color space compression information (information relating to the correspondence between reference colors and sRGB values) used for LUT generation in the color space compression II section (216) will be described.

  The flow of processing when creating a color space compression DB including color space compression information of the output device (DEV1) serving as a reference from the color patches for the defined color space is shown in FIG. The defined color space may be a color space that can be converted into XYZ or Lab and can determine whether the color reproduction range is inside or outside, such as sRGB or Adobe RGB, and may be XYZ or Lab itself. Hereinafter, a case where the defined color space is sRGB will be described as an example.

  First, an application, a driver, and a controller are set so that an RGB image on the PC (201) is output in sRGB, and a color patch (203) in the sRGB device color space is prepared (step S1401). Here, the sRGB color patch (203) is a color patch such as 9 × 9 × 9 or 17 × 17 × 17 in which each channel is equally divided.

  Next, as shown in FIG. 14, the sRGB color patch (203) is printed out to the printer (DEV1 (202)) to be used as the “reference” (step S1402), and colorimetry is performed by the colorimeter (204) ( Step S1403). Then, the relationship between the sRGB values on the sRGB color patch (203) and the PCS values (XYZ or Lab) is stored in the color space compression DB (205) as color space compression information (step S1404).

  An example of the color space compression information constituting the color space compression DB (205) is shown in FIG. The data format to be stored may be an ASCII format or a binary format. GMDB Type (color space compression type) 1201 is “when using a color patch for a defined color space”, “when using a color patch for a device color space of an ICC profile” (details will be described later), and “reference and This is a type used to distinguish acquisition information for acquiring color space compression information, such as “when using an ICC profile of a device” (details will be described later). Here, “when using a color patch for a defined color space” is type 1.

  The Input Color Space (input color space) 1205 and the Output Color Space (output color space) 1206 are, for example, when the defined color space is sRGB, the input color space 1205 is “sRGB”, and the output color space 1206 is For example, “Lab”.

  White Point 1202 is an XYZ value for sRGB (100%, 100%, 100%), and Black Point 1203 is an XYZ value for sRGB (0%, 0%, 0%).

  Patch Information (patch information) 1204 indicates the configuration of the color patch, and stores information such as RGB 9x9x9, RGB 17x17x17, CMYK 9x9x9x5, CMYK IT8.7 / 3, Lab 17x17x17, and the like. When the input color space 1205 is sRGB, RGB 9x9x9, RGB 17x17x17, or the like is used. Here, the configuration of the color patch is not limited to a patch in which each channel of the “input color space” is equally divided, and may be non-uniform. The colorimetric value stores a value measured based on the configuration of the color patch, and its color space matches the “output color space” (1206).

<Creation of colorimetric value file>
On the other hand, it is necessary to obtain a colorimetric value (210) in order to realize faithful color reproduction of the printer (DEV2 (207)) that is actually used, apart from the printer (DEV1 (202)) that is to be set as the “reference”. . Hereinafter, a method for obtaining the colorimetric value will be described.

  First, a color patch (208) having the same color space as the device color space of the printer (DEV2 (207)) to be actually used is prepared, and the color patch (208) is output as it is from the PC (206). , Driver and controller settings. For example, when the device color space of the printer (207) is CMYK, a color patch such as CMYK 9x9x9x5 or CMYK IT8.7 / 3 is prepared.

  Next, the CMYK color patch (208) is printed out to the printer (207) that actually uses the same work flow as when the color space compression DB (205) is created, and measured by the colorimeter (209). To color. Then, the relationship between the CMYK value on the CMYK color patch (208) and the PCS value (XYZ or Lab) is stored as a colorimetric value file (210).

  An example of internal data of the colorimetric value file (210) is shown in FIG. The data format to be stored may be an ASCII format or a binary format. For example, when the device color space of the printer (207) to be actually used is CMYK, the input color space (input color space) 1301 and the output color space (output color space) 1302 are “ CMYK ”and the output color space (1302) is, for example,“ Lab ”.

  White Point 1303 is an XYZ value for CMYK (0%, 0%, 0%, 0%), and Black Point 1304 is an XYZ for CMYK (100%, 100%, 100%, 100%). Value.

  The Patch Information (patch information) 1305 indicates the configuration of the color patch, and stores information such as RGB 9x9x9, RGB 17x17x17, CMYK 9x9x9x5, CMYK IT8.7 / 3, Lab 17x17x17, etc., similar to the creation of the color space compression DB. To do. When the input color space (1301) is CMYK, CMYK 9x9x9x5, CMYK IT8.7 / 3, or the like is used. Here, the configuration of the color patch is not limited to a patch in which each channel of the “input color space” (1301) is equally divided, and may be non-uniform. The colorimetric value stores a value measured based on the configuration of the color patch, and its color space matches the “output color space” (1302).

<Output profile generation method>
Next, using the information of the color space compression DB (205) and the colorimetric value file (210), the same color space compression as that of the “reference” printer (DEV1) is realized on another printer (DEV2). A processing procedure of the profile creation software for creating the output profile (220) will be described. The output profile has an A2Bx tag for storing the conversion from the device color to the PCS value and a B2Ax tag for storing the conversion from the PCS value to the device color. Here, in the case of the A2B0 tag and B2A0 tag, each tag is It will be described as being created.

  An example of generating an A2B0 tag of the output profile (220) is shown in FIG. The colorimetric values stored in the colorimetry value file (210) are absolute values, and the white point and black point indicate the media white point and media black point. When creating an ICC profile, it is necessary to use a colorimetric value relative to the media white point, so correction (218) needs to be performed in consideration of the media white point and the media black point.

  Here, FIG. 11 compares the result (a) of correction using only the media white point and the result (b) of correction using the media white point and the media black point. The left side shows the source side, and the right side shows the destination side. When the correction is performed only with the media white point, the corrected black point may float too much, and it is understood that it is better to perform the correction in consideration of the media black point.

  Media white point before correction is MW1 (Xmw1, Ymw1, Zmw1), media black point before correction is MK1 (Xmk1, Ymk1, Zmk1), media white point after correction is MW2 (Xmw2, Ymw2, Zmw2), and after correction If the media black point is MK2 (Xmk2, Ymk2, Zmk2), conversion from the colorimetric values (X1, Y1, Z1) in the colorimetric value file to the corrected colorimetric values (X2, Y2, Z2) For example, the equation is expressed by the above equation (4) using Bradford conversion as a chromatic adaptation model.

  Here, the chromatic adaptation model does not need to be limited to the Bradford conversion, and Von Kries conversion, CIECAM97s, or the like may be used instead.

  Returning to FIG. Read the colorimetric value file (210), for example, the white point in the colorimetric value file (210) as the media white point before correction, the black point of the colorimetric value file (210) as the media black point before correction, and correction If D50 is set as the subsequent media white point and the uncorrected media black point is set as the corrected media black point, and equation (4) is applied (218), the black point floats relative to the media white point. The suppressed colorimetric values (X2, Y2, Z2) can be obtained.

  Finally, if the relationship between the device color of DEV2 and the corrected colorimetric values (X2, Y2, Z2) is stored in the multidimensional LUT, an A2B0 tag LUT can be created (step S1701). Here, the multidimensional LUT is a 3D LUT when the device color space is RGB, and a 4D LUT when the device color space is CMYK.

<User interface for color space compression DB generation>
An example of a user interface for creating a color space compression DB is shown in FIG. “From Defined Color Space Patches (when creating color space compression information of a reference output device from a color patch for a defined color space)” (2801), “From ICC Profile Color Space Patches (ICC Profile Device Color Space) (When creating color space compression information of reference output device from color patch) ”(2802, details will be described later),“ From Reference ICC Profile (creating color space compression information of reference output device from ICC profile) Case) ”(2803, details will be described later), the user can select one.

  When “when creating color space compression information of a reference output device from a color patch for a defined color space” (2801) is selected, “Defined Color Space (definition) set at the time of print output is selected. Color space) ”(2801-1),“ Color Patches Type ”(2801-2) used for print output,“ PCS ”(2801-3) obtained from colorimetric values, and the like can be selected. .

  When “when generating color space compression information of reference output device from color patch for device color space of ICC profile” (2802) is selected, the color space of the image is defined when printing. “Source Profile (source profile)” (2802-1), “Color Patches Type (patch information)” (2802-2) used for print output, “PCS” (2802-3) obtained from colorimetric values, etc. You can choose.

  When “Creating a reference from an ICC profile” (2803) is selected, “Reference Profile (reference profile)” (2803-1) as a reference and “Rendering Intent” (2803-) to be extracted from the profile are selected. 2) can be set. When two or more Rendering Intents are selected, it is stored as a type 0 color space compression DB.

<User interface for output profile generation>
An example of a user interface for the output profile is shown in FIG. As settings for the color space compression DB, a color space compression DB file can be selected (2901) and white point / black point correction can be selected (2902). As settings for the colorimetric values, a colorimetric value file can be selected (2903) and white point / black point correction can be selected (2904).

  As is clear from the above description, according to the present embodiment, the color space of the output device serving as a reference using the color patch printed out from DEV1 by applying a defined color space such as sRGB or AdobeRGB. By creating the compression information and configuring the color space compression II based on the information, the same color reproduction as that of the printer (DEV1) realizing the desired color reproduction can be realized in the DEV2.

[Second Embodiment]
In this embodiment, a case will be described in which color space compression is performed using color space compression information of a reference output device created based on a color patch for a device color space of an ICC profile.

<Flow of processing in image processing apparatus>
The flow of processing in the output profile (313) will be described with reference to 313 in FIG. 3 and FIG.

  In step S1901, a color space compression II part (312) LUT is created. In creating the LUT of the color space compression II section (312), first, the color space compression DB (305) storing the relationship between the CMYK values and PCS values corresponding to the SWOP is read, and the A2B0 tag is generated. As in the case, white point / black point correction (311) is performed by applying the equation (4). At this time, the white point and black point in the color space compression DB (305) are used as the media white point and media black point before correction.

  Next, if the relationship between the CMYK value and the corrected PCS value is stored in the 4D LUT, the LUT of the color space compression II section (312) can be created. The advantage of leaving the input color space of the LUT of the color space compression II section (312) as CMYK is that the accuracy in the CMYK space can be maintained rather than using other color spaces such as Lab.

  In step S1902, an LUT for the faithful color reproduction unit (219) is created. In creating the LUT of the faithful color reproduction unit (219), the colorimetric value file (210) in which the relationship between the device color of DEV2 and the PCS value is stored is read, and “the color patch for the defined color space is used. The LUT of the faithful color reproduction unit (219) is created by the same processing as in “Case”. In step S1903, the SWOP profile (306) is acquired.

  The B2A0 tag 3D LUT is created using the LUT of the color space compression II section (312) and the LUT of the faithful color reproduction section (219) obtained by the above processing. The following processing is performed for each PCS value corresponding to the grid point of the 3D LUT.

  First, an input color (PCS value) is acquired in step S1904, and a SWOP inside / outside determination (308) is performed on the PCS value in step S1905. If it is determined that the color is outside the SWOP color reproduction range, the color space compression I unit (309) is applied (step S1906). Here, the SWOP inside / outside determination unit (308) can use the gammut tag of the source side SWOP profile (306) stored in the color space compression DB (305).

  In the color space compression I section (309), colors outside the SWOP color reproduction range are mapped to the surface of the SWOP color reproduction range or in the vicinity of the surface, and colors within the SWOP color reproduction range are faithfully or as faithfully reproduced as possible. Color space compression is performed.

  FIG. 25 shows an example of color space compression on the Lab color space. Here, the color space used for color space compression need not be limited to Lab, and may be a color space such as Luv or JCH. First, a point P0 on the achromatic color axis that is a target when color space compression is performed on the color P1 outside the SWOP color reproduction range is determined. Here, the target point P0 has the same brightness as the point P2 having the maximum saturation Cmax on the surface of the SWOP color reproduction range having the same hue as the color P1 outside the SWOP color reproduction range.

  Next, as shown in FIG. 26, the midpoint P1 ′ between the point P1 and the target point P0 is moved along the locus on the equal hue connecting the point P1 and the point P0, and the intersection point with the surface of the color reproduction range is obtained. Let point P3 after color space compression. At this time, the movement of the point along the locus on the same hue is performed, for example, when the midpoint of the point P0 and the point P1 is set as the movement point P1 ′ and the SWOP inside / outside determination unit (308) is applied to be within the color reproduction range. Performs processing so that the midpoint of the points P1 ′ and P1 is a new moving point, and if it is outside the color reproduction range, the midpoint of the points P0 and P1 ′ is the new moving point. If the device color space of the ICC profile is XYZ or Lab, the input color space in the color space compression II section (312) is XYZ or Lab, and therefore the application of the color space compression I section (309) is omitted. be able to.

  After the color space compression I section (309) is applied in step S1906 or when it is determined in step S1905 that the SWOP is within the color reproduction range, the process proceeds to step S1907. In step S1907, in order to apply the LUT of the color space compression II section (312), the PCS values that fall within the SWOP color reproduction range are converted into CMYK values. Here, the conversion (310) from the PCS value to the CMYK value is performed by using the B2A1 tag of the source side profile (306) stored in the color space compression DB (305).

  In step S1908, the LUT of the color space compression II part (312) is applied. Application of the color space compression II part (312) is performed by tetrahedral interpolation of a 4D LUT or the like. Here, the PCS value after LUT interpolation falls within the color reproduction range of the reference device.

  In step S1909, it is determined whether or not the output device (DEV2) is within the color reproduction range. If it is determined that the output device (DEV2) is not within the color reproduction range, “use color patch for defined color space is used. In the same manner as in the case of “Yes”, the process proceeds to step S1910, and after applying the color space compression part III (217), the desired device color is obtained by applying the LUT of the faithful color reproduction part (219) in step S1911. be able to.

  On the other hand, if it is determined in step S1909 that it is within the color reproduction range, the process advances to step S1911 to apply the LUT of the faithful color reproduction unit (219). Here, the application of the LUT of the faithful color reproduction unit (219) is performed by tetrahedral interpolation of the 3D LUT or the like.

  In step S1912, it is determined whether or not processing has been completed for all input colors. If it is determined that processing has not been completed, the process returns to step S1904. On the other hand, if it is determined that the process has been completed, the process ends.

  In this way, the B2A0 tag can be created by storing the device color obtained using each PCS value corresponding to the 3D LUT lattice point as the input color in the 3D LUT. Here, the number of output channels of the 3D LUT is 3 when the output device is RGB, and 4 when the output device is CMYK.

<Generation method of color space compression DB>
The flow of processing when creating a color space compression DB including the color space compression information of the output device as a reference from the color patch for the device color space of the ICC profile is shown in 314 of FIG. 3 and FIG. Here, the device color space of the ICC profile of DEV1 as a reference may be any of RGB, CMYK, XYZ, and Lab. Hereinafter, a case where the device color space is SWOP (CMYK) will be described as an example.

  First, the application, driver, and controller are set so that the CMYK image on the PC (301) is output by SWOP. At this time, SWOP (306) is set as the source side profile, and the profile (307) of the output device serving as a reference is set as the destination side profile (step S1501). Then, a color patch (303) of the CMYK device color space which is the same device color space as the source side profile is prepared. Here, the CMYK color patch (303) is, for example, a color patch such as 9 × 9 × 9 × 5 in which each channel is equally divided or IT8.7 / 3 used as a standard chart.

  Next, the CMYK color patch (303) is printed out to the printer (DEV1 (302)) to be used as the “reference” (step S1502), and the colorimetry (304) is used for colorimetry (step S1503). Then, the relationship between the SWOP value on the CMYK color patch (303) and the PCS value (XYZ or Lab) is stored in the color space compression DB (305) as color space compression information (step S1504).

  An example of the internal configuration of the color space compression information stored in the color space compression DB (305) is shown in FIG. The data format at the time of storing may be an ASCII format or a binary format. GMDB Type (color space compression type) 1201 is “when using a color patch for a defined color space”, “when using a color patch for a device color space of an ICC profile”, or “an ICC profile of a reference device” Is a type used to distinguish an acquisition method for acquiring color space compression information, such as Here, “when using a color patch for the device color space of the ICC profile” is type 2.

  For example, when the device color space of the ICC profile is CMYK, the input color space 1205 and the output color space (output color space) 1206 are “CMYK”, and the output color space 1206 is the output color space 1206. Is, for example, “Lab”.

  White Point 1202 is an XYZ value for CMYK (0%, 0%, 0%, 0%), and Black Point 1203 is an XYZ for CMYK (100%, 100%, 100%, 100%). Value.

  Patch Information (patch information) 1204 indicates the configuration of the color patch, and stores information such as RGB 9x9x9, RGB 17x17x17, CMYK 9x9x9x5, CMYK IT8.7 / 3, Lab 17x17x17, and the like.

  When the Input Color Space (input color space) 1205 is CMYK, CMYK 9x9x9x5, CMYK IT8.7 / 3, or the like is used. Here, the configuration of the color patch is not limited to a patch in which each channel of the “input color space” is equally divided, and may be non-uniform. Measurement Data (colorimetric value) 1207 stores a value measured based on the configuration of the color patch, and the color space thereof coincides with the “output color space” (Output Color Space 1206).

  In addition, in the case of “using a color patch for the device color space of the ICC profile” (type 2), the source side profile (SWOP in the example) when the color patch is output is also stored (ICC Profile 1208). Here, the stored source side profile is the ICC profile itself or a file name indicating the ICC profile.

<Creation of colorimetric value file>
On the other hand, apart from the printer (DEV1 (302)) to be used as the “reference”, in order to realize faithful color reproduction of the printer (DEV2 (207)) that is actually used, “color patches for the defined color space are used. Similarly to the case (see the first embodiment), a colorimetric value file (210) is created.

<Output profile generation method>
Next, using the information in the color space compression DB (305) and the colorimetric value file (210), the same color space compression as that of the “reference” printer (DEV1 (302)) is applied to another printer (DEV2 (207)). ) Processing of the profile creation software for creating the output profile (313) as realized above will be described (FIG. 3). The output profile has an A2Bx tag for storing the conversion from the device color to the PCS value and a B2Ax tag for storing the conversion from the PCS value to the device color. Here, in the case of the A2B0 tag and B2A0 tag, each tag is It will be described as being created.

  For the A2B0 tag of the output profile (313), a multi-dimensional LUT is generated from the colorimetric value file (210) by the same processing (FIG. 17) as “when using a color patch for the defined color space”. Store it.

  As is clear from the above description, according to the present embodiment, the color space compression information of the output device serving as a reference is created using the color patch printed out from DEV1 by applying the device color space of the ICC profile. By configuring the color space compression II based on the information, the same color reproduction as that of the printer (DEV1) realizing the desired color reproduction can be realized also in the DEV2.

[Third Embodiment]
In the present embodiment, a case will be described in which color space compression is performed using color space compression information created based on an ICC profile of a reference output device.

<Flow of processing in image processing apparatus>
A processing flow in the output profile (406) will be described with reference to 406 in FIG. 4 and FIG.

  First, in step S2001, a color space compression II part (405) LUT is generated. In creating the LUT of the color space compression II section (405), the expression (in the same way as when the color space compression DB (403) storing the relationship between the PCS value and the PCS value is read and the A2B0 tag is generated. Applying 4), white point / black point correction (404) is performed. At this time, the white point and black point in the color space compression DB (403) are used as the media white point and media black point before correction. Normally, in the case of “when using the ICC profile of the device serving as a reference”, the white point and the black point after correction match each other, and this process can be skipped. If the relationship between the PCS value and the PCS value is stored in the 3D LUT, the color space compression II part (405) LUT can be created. At this time, the color reproduction range of the PCS value on the input side is limited by the color reproduction range such as “when using a color patch for a defined color space” or “when using a color patch for a device color space of an ICC profile”. Therefore, processing such as the color space compression I section (213 or 309) is not necessary.

  In step S2002, an LUT for the faithful color reproduction unit (219) is created. The LUT of the faithful color reproduction unit (219) reads the color measurement value file (210) in which the relationship between the device color of DEV2 and the PCS value is stored, and “when using a color patch for a defined color space” It is created by similar processing.

  A BD2 tag tag 3D LUT is created using the LUT of the color space compression II section (405) and the LUT of the faithful color reproduction section (219) obtained by the above processing. The following processing is performed for each PCS value corresponding to the grid point of the 3D LUT.

  In step S2003, an input color (PCS value) is acquired. In step S2004, the LUT of the color space compression II unit (405) is applied to the input PCS value. The application of the color space compression II part (405) is performed by tetrahedral interpolation of a 3D LUT or the like. Here, the PCS value after LUT interpolation falls within the color reproduction range of the reference device (DEV1).

  In step S2005, it is determined whether or not the output device (DEV2) is within the color reproduction range. If it is determined that the output device (DEV2) is not within the color reproduction range, “when a color patch for a defined color space is used” is determined. Similarly, the desired device color can be obtained by applying the LUT of the color space compression III part (217) and the faithful color reproduction part (219) (steps S2006 and S2007). On the other hand, if it is determined that it is within the color reproduction range, the LUT of the faithful color reproduction unit (219) is applied in step S2007. Here, the application of the LUT of the faithful color reproduction unit (219) is performed by tetrahedral interpolation of the 3D LUT or the like.

  In this way, the B2A0 tag can be created by storing the device color obtained using each PCS value corresponding to the 3D LUT lattice point as the input color in the 3D LUT. Here, the number of output channels of the 3D LUT is 3 when the output device is RGB, and 4 when the output device is CMYK.

<Generation method of color space compression DB>
FIG. 4 and FIG. 16 show the flow of processing when creating a color space compression DB from the ICC profile of the reference device (DEV1). The device color space of the reference ICC profile device (DEV1) may be RGB or CMYK.

  First, as shown in FIG. 16, the profile (401) of the printer (DEV1) to be set as “reference” is acquired (step S1601), and it is confirmed whether or not the Preview tag exists (step S1602). If the Preview tag exists, the conversion of the Preview tag is used as it is. If the Preview tag does not exist, the conversion from the B2Ax tag to the A2Bx tag is performed, and the PCS value (XYZ or Lab) and the PCS value after color space compression are performed. Are stored in the color space compression DB (403) (steps S1603 and S1604). Here, the Rendering Intent used in the Preview tag, the B2Ax tag, and the A2Bx tag is specified by the user through the user interface (FIG. 28).

  An example of internal data of the color space compression DB (403) is shown in FIG. The data format to be stored may be an ASCII format or a binary format. GMDB Type (color space compression type) 1201 is “when using a color patch for a defined color space”, “when using a color patch for a device color space of an ICC profile”, or “an ICC profile of a reference device” This is a type used to distinguish "when using". Here, “when using an ICC profile of a device serving as a reference” is type 3.

  The Input Color Space (input color space) 1205 and the Output Color Space (output color space) 1206 are, for example, when the PCS of the ICC profile is Lab, the input color space 1205 is “Lab”, and the output color space 1206 is also “ Lab ".

  White Point (white point) 1202 is the XYZ value of D50, which is the white point of PCS, and Black Point (black point) 1203 is the XYZ value (0, 0, 0), which is the black point of PCS.

  Patch Information (patch information) 1204 indicates the configuration of the color patch, and stores information such as RGB 9x9x9, RGB 17x17x17, CMYK 9x9x9x5, CMYK IT8.7 / 3, Lab 17x17x17, and the like. When the input color space is PCS, Lab 17x17x17, XYZ 33x33x33, or the like is used. Here, the configuration of the color patch is not limited to a patch in which each channel of the “input color space” is equally divided, and may be non-uniform. The color patch configuration of “when using the ICC profile of the reference device (DEV1)” is a configuration of lattice points generated using the Preview tag, the B2Ax tag, and the A2Bx tag. The colorimetric value stores a value measured based on the configuration of the color patch, and its color space matches the “output color space”.

<Creation of colorimetric value file>
On the other hand, in addition to the ICC profile (401) of the output device that becomes the “reference”, in order to realize faithful color reproduction of the printer (DEV1 (207)) that is actually used, “use color patches for the defined color space” In the same manner as in “When to do”, a colorimetric value file (210) is created.

<Output profile generation method>
An output profile that realizes the same color space compression on the other printer (DEV2) as the “reference” printer (DEV1) using the information of the color space compression DB (403) and the colorimetric value file (210). The process of the profile creation software for creating (406) will be described (FIG. 4). The output profile has an A2Bx tag for storing the conversion from the device color to the PCS value and a B2Ax tag for storing the conversion from the PCS value to the device color. Here, in the case of the A2B0 tag and B2A0 tag, each tag is It will be described as being created.

  For the A2B0 tag of the output profile (406), a multidimensional LUT is generated from the colorimetric value file (210) by the same processing (FIG. 17) as “when using a color patch for the defined color space”. Store it.

  As is apparent from the above description, according to the present embodiment, a printer (DEV1) that realizes a desired color reproduction by configuring the color space compression II based on a reference created from the ICC profile of DEV1. It is possible to realize the same color reproduction even in DEV2. Further, the output profile (ICC profile) of the printer (DEV1) that realizes the desired color reproduction can be reused for DEV2 color reproduction.

[Fourth Embodiment]
In the first to third embodiments, the color space compression I part to the color space compression III part (or the color space compression II part and the color space compression III part) are used as one output profile (220, 313, 406). Although configured, the present invention is not limited to this, and may be configured as two modules. In the following embodiments, a case will be described in which the color space compression I part and the color space compression II part are configured as a part of a CMM (color management module) and the color space compression III part is configured as a part of an output module.

<Flow of processing in image processing apparatus>
FIG. 5 and FIG. 21 show an example of CMM processing that uses the color space compression DB (205) to realize the same color space compression on the other printer (DEV2) as the “reference” printer (DEV1). .

  First, the color space compression DB (205) in which the relationship between sRGB values and PCS values is stored is read, and white point / black point correction (215) is performed by applying equation (4). Next, the relationship between the sRGB value and the corrected PCS value is stored in the 3D LUT, and the LUT of the color space compression II part (216) is created (step S2101).

  In step S2102, the input profile (211) is applied to the device input color to obtain an input PCS value. Next, in step S2103, the sRGB color reproduction range inside / outside determination (212) is performed on the input PCS value, and if it is outside the sRGB color reproduction range, the process proceeds to step S2104, and the color space compression I unit (213) is applied. On the other hand, if it is within the sRGB color reproduction range, the process proceeds to step S2105. If the defined color space is XYZ or Lab, the input color space in the color space compression II section (216) is XYZ or Lab, and therefore the processing of the color space compression I section (213) is omitted. Can do.

  In step S2105, the PCS values that fall within the sRGB color reproduction range are converted (214) into sRGB values by applying Equation (1), Equation (2), Equation (2a), and Equation (2b). The LUT of the space compression II part (216) is applied (step S2106). Here, the PCS value obtained by tetrahedral interpolation or the like falls within the color reproduction range of the reference device.

  In step S2107, it is determined whether or not the processing has been completed for all input colors. If not, the process returns to step S2102. On the other hand, if completed, the CMM internal processing is terminated.

  The output profile (502) can then be applied to obtain the desired device color. Here, unlike the profile creation software, the color space compression part III (217) uses the B2Ax tag of the output profile, and therefore does not need to be performed as an internal process of the CMM.

<User interface>
An example of the setting of the color management module is shown in FIGS. FIG. 30 shows an example of a UI when color matching is performed using two profiles on the source side (3001) and the destination side (3004). Rendering Intent selection (3002) and color space compression DB file Selection (3003) is possible. When the color space compression DB is type 0, the Rendering Intent in the color space compression DB and the Rendering Intent of the destination side profile are synchronized with the Rendering Intent (3002). When the color space compression DB is other than type 0, only the Rendering Intent of the destination side profile is synchronized with the Rendering Intent.

  Similarly, FIG. 31 shows a UI when color matching is performed using three profiles of the source side (3101), the target side (3102), and the destination side (3103).

  As is clear from the above description, if the processing of FIG. 21 is applied using each PCS value corresponding to the 3D LUT lattice point as an input color and the obtained PCS value is stored in the 3D LUT in advance, Since processing can be performed only for 3D LUT interpolation processing, CMM internal processing can be speeded up.

[Fifth Embodiment]
In the fourth embodiment, the case where the color space compression information of the output device as a reference created based on the color patch for the defined color space such as sRGB or AdobeRGB is used has been described. A case where the color space compression information of the output device serving as a reference created based on the color patch for the device color space of the ICC profile is used will be described.

<Flow of processing in image processing apparatus>
6 and 22 show the flow of CMM processing that uses the color space compression DB (305) to realize the same color space compression on the other printer (DEV2) as the “reference” printer (DEV1). .

  First, in step S2201, a color space compression II part (216) LUT is created. In creating the LUT of the color space compression II section (216), the color space compression DB (305) storing the relationship between CMYK values and PCS values corresponding to SWOP is read, and the white space is applied by applying equation (4). Point / black point correction (311) is performed. Next, the relationship between the CMYK value and the corrected PCS value is stored in the 4D LUT, thereby creating the LUT of the color space compression II section (312).

  In step S2202, a SWOP profile is acquired from the SWOP profile (306).

  In step S2203, the input profile (211) is applied to the device input color to obtain an input PCS value. In step S2204, the SWOP color reproduction range inside / outside determination (308) is performed by applying the gamut tag of the source-side SWOP profile (306) stored in the color space compression DB (305) to the input PCS value. If it is determined that the color is outside the SWOP color reproduction range, the color space compression I unit (309) is applied (step S2205). When the device color space of the ICC profile is XYZ or Lab, the input color space of the color space compression II unit (312) is XYZ or Lab, and therefore the color space compression I unit (309) may be omitted. it can.

  In step S2206, the PCS value within the SWOP color reproduction range is converted to a CMYK value by applying the B2A1 tag of the source-side SWOP profile (306) stored in the color space compression DB (305). (310), and the LUT of the color space compression II part (312) is applied (step S2207). Here, the PCS value obtained by tetrahedral interpolation or the like falls within the color reproduction range of the reference device (DEV1).

  In step S2208, it is determined whether or not the processing has been completed for all input colors. If not, the process returns to step S2203. On the other hand, if it is determined that the process has been completed, the CMM internal process is terminated.

  Thereafter, the output profile (502) on the destination side can be applied to obtain a desired device color. Here, unlike the profile creation software, the color space compression III part (217) uses the B2Ax tag of the destination profile, and therefore does not need to be performed as CMM internal processing.

  As is clear from the above description, if the PCS values corresponding to the 3D LUT lattice points are used as input colors and the processing of FIG. 22 is applied and the obtained PCS values are stored in the 3D LUT in advance, Since processing can be performed only for 3D LUT interpolation processing, CMM internal processing can be speeded up.

[Sixth Embodiment]
In the fourth and fifth embodiments, when using the color space compression information of the output device as a reference created based on the color patch for the defined color space such as sRGB or AdobeRGB, Although the case where the color space compression information of the reference output device created based on the color patch for the device color space is used has been described, in the present embodiment, the ICC profile of the reference device (DEV1) is used. Will be described.

<Flow of processing in image processing apparatus>
FIG. 7 and FIG. 23 show the flow of CMM internal processing that uses the color space compression DB (403) to realize the same color space compression on the other printer (DEV2) as the “reference” printer (DEV1). Show.

  In step S2301, a color space compression II part (405) LUT is created. In creating the LUT of the color space compression II section (405), first, the color space compression DB (403) in which the relationship between the PCS value and the PCS value is stored is read, and the white point / Black point correction (404) is performed. Normally, when using the ICC profile of the reference device, the white point and the black point before and after the correction are the same, so the white point / black point correction (404) is skipped. Is done. Then, by storing the relationship between the PCS value and the PCS value in the 3D LUT, a color space compression II part (LUT) LUT is created.

  In step S2302, the input profile (211) is applied to the device input color to obtain an input PCS value.

  In step S2303, the LUT of the color space compression II part (405) is applied. Here, the PCS value obtained by tetrahedral interpolation or the like falls within the color reproduction range of the reference device.

  In step S2304, it is determined whether or not processing has been completed for all input colors. If processing has not been completed, the process returns to step S2302. On the other hand, if it is determined that the process has been completed, the CMM internal process is terminated.

  The output profile (502) can then be applied to obtain the desired device color. Here, unlike the profile creation software, the color space compression III part (217) uses the B2Ax tag of the destination profile, and therefore does not need to be performed as CMM internal processing.

[Seventh Embodiment]
In the first to sixth embodiments, one color space compression DB exists for each Rendering Intent. However, depending on each Rendering Intent, such as the B2A0 tag, B2A1 tag, and B2A2 tag of the ICC profile. The color space compression DB may be saved as one file. Therefore, in this embodiment, a case will be described in which processing is switched based on the GMDB type of the color space compression DB.

  FIG. 27 shows a file format for storing a plurality of color space compression DBs in one file. Here, the GMDB type (2701) is type 0. Offset (offset) 2702 to 2704 stores the head address of the color space compression DB corresponding to each Rendering Intent.

  As described above, different GMDB type information can be stored in the color space compression DB. FIG. 8 and FIG. 9 show the basic configuration when different types of GMDB types are automatically discriminated internally, and perform processing by type, and FIG.

  In step S2401, the color space compression DB selected by the user via the user interface is read in the profile creation software (801) or the CMM internal processing (501, 601, 701). In step S2402, the read GMDB type is determined (FIGS. 30 and 31). If it is determined in step S2402 that GMDB type = 0, the process proceeds to step S2403, and the offset of the desired color space compression DB is acquired by the rendering intent selected by the user via the user interface, and in accordance with the rendering intent. Extract the color space compression DB from the file. Then, the following processing is continued for the extracted color space compression DB.

  In step S2404, it is determined whether the GMDB type is 1. When the GMDB type is 1, it is determined whether or not the input color space is a supported color space (sRGB, Adobe RGB, WG RGB) in step S2405 (steps S2405 to S2406), and the supported color space. If so, processing corresponding to the input color space is performed (steps S2410, S2411, and S2412). On the other hand, if it is not supported, the process advances to step S2408 to output an error.

  If it is determined in step S2404 that the GMDB type is not 1, it is determined in step S2409 whether the GMDB type is 2. If the GMDB type is 2, the source side profile and the colorimetric value are extracted from the color space compression DB, and the ICC profile is processed for the device color space (step S2413). On the other hand, if the GMDB type is 3, the process for the reference ICC profile is performed (step S2414).

[Eighth Embodiment]
In each of the above embodiments, the case where the color space compression DB is used has been described. However, the output profile creation and color matching are performed based on the color space compression information in a memory (not shown) without using the color space compression DB. You can do it.

[Other Embodiments]
Note that the present invention can be applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, and a printer), and a device (for example, a copying machine and a facsimile device) including a single device. You may apply to.

  Another object of the present invention is to supply a storage medium recording a program code of software for realizing the functions of the above-described embodiments to a system or apparatus, and the computer (or CPU or MPU) of the system or apparatus stores the storage medium. Needless to say, this can also be achieved by reading and executing the program code stored in.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention.

  As a storage medium for supplying the program code, for example, a floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD-R, magnetic tape, nonvolatile memory card, ROM, or the like is used. be able to.

  Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (operating system) operating on the computer based on the instruction of the program code. It goes without saying that a case where the function of the above-described embodiment is realized by performing part or all of the actual processing and the processing is included.

  Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. It goes without saying that the CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

It is a figure which shows the flow of a general color matching process. It is a figure which shows the function structure of the output profile of the image processing apparatus concerning the 1st Embodiment of this invention. It is a figure which shows the flow of a process in the case of producing color space compression DB provided with the color space compression information of the output device used as a reference from the color patch with respect to the device color space of an ICC profile. It is a figure which shows the flow of a process in the case of producing color space compression DB from the ICC profile of the device (DEV1) used as a reference. It is a figure which shows an example of CMM processing which implement | achieves the same color space compression as the printer (DEV1) used as a "reference" on another printer (DEV2) using color space compression DB (205). FIG. 10 is a diagram showing a flow of CMM processing that uses the color space compression DB (305) to realize the same color space compression on the other printer (DEV2) as the “reference” printer (DEV1). FIG. 10 is a diagram illustrating a flow of CMM internal processing that uses the color space compression DB (403) to realize the same color space compression on the other printer (DEV2) as the “reference” printer (DEV1). It is a figure which shows the basic composition in case profile creation software processes a different type of color space compression DB. It is a figure which shows the basic composition in case CMM processes different types of color space compression DB. It is a figure which shows the basic concept of the process in the image processing apparatus concerning one Embodiment of this invention. It is a figure which shows the basic concept of white point and black point correction | amendment. It is a figure which shows an example of the internal data of color space compression DB. It is a figure which shows an example of the internal data of a colorimetric value file. It is a flowchart which shows the flow of a process in the case of producing the color space compression DB used as a reference from the color patch with respect to the defined color space. It is a flowchart which shows the flow of a process in the case of producing color space compression DB provided with the color space compression information of the output device used as a reference from the color patch with respect to the device color space of an ICC profile. It is a flowchart which shows the flow of a process in the case of producing color space compression DB from the ICC profile of the device (DEV1) used as a reference. It is a flowchart in the case of producing | generating an A2B0 tag. It is a flowchart which shows the flow of a process in the case of producing | generating a B2A0 tag from color space compression DB when the color patch with respect to the defined color space is made into a reference. It is a flowchart which shows the process example in the case of producing | generating a B2A0 tag from color space compression DB when the color patch with respect to the device color space of an ICC profile is made into a reference. It is a flowchart which shows the flow of a process in the case of producing | generating a B2A0 tag from color space compression DB at the time of making an ICC profile into a reference. It is a flowchart which shows the flow of a process in the case of performing color matching using color space compression DB when the color patch with respect to the defined color space is made into a reference. It is a flowchart which shows the flow of a process in the case of performing color matching using color space compression DB at the time of making the color patch with respect to the device color space of an ICC profile into a reference. It is a flowchart which shows the flow of a process in the case of performing color matching using color space compression DB at the time of making an ICC profile into a reference. It is a flowchart which shows the flow of a process in the case of automatically discriminating a different GMDB type internally, and performing a process according to type. It is a figure which shows an example of color space compression. It is a figure which shows an example of the mapping method of color space compression. It is a figure which shows the file format for storing several color space compression DB in one file. It is a figure which shows an example of the user interface in the case of creating color space compression DB. It is a figure which shows an example of the user interface in the case of producing a profile using color space compression DB. It is a figure which shows an example of the user interface in the case of performing color matching using color space compression DB. It is a figure which shows an example of the user interface in the case of performing color proofing using color space compression DB.

Claims (12)

An image processing apparatus that compresses an input image in color space and outputs the compressed image to an output device,
First color space compression means for color space compressing the input image converted into a device-independent color space within a color reproduction range of an output device of a type different from the output device;
An image processing apparatus comprising: a second color space compression unit that compresses the input image color space compressed by the first color space compression unit within a color reproduction range of the output device. . The first color space compression means includes
Look-up table generated based on color space compression information of different types of output devices obtained by measuring a color patch printed and output by the different types of output devices by applying a predetermined color space The image processing apparatus according to claim 1, wherein color space compression is performed using the image processing apparatus. The first color space compression means includes
A lookup table generated based on the color space compression information of the different types of output devices obtained by measuring the color patches printed out from the color spaces of the ICC profiles of the different types of output devices. The image processing apparatus according to claim 1, wherein color space compression is performed using the image processing apparatus. The first color space compression means includes
The image processing apparatus according to claim 1, wherein color space compression is performed using a lookup table generated based on output profiles of the different types of output devices. Color space compression information of the different types of output devices obtained by measuring the color patches printed out in the different types of output devices by applying a predetermined color space, and the different types of output devices Holding that holds the color space compression information of the different types of output devices obtained by measuring the color patches printed out from the color space of the ICC profiles that the ICC profile has, and the ICC profiles that the different types of output devices have The image processing apparatus according to claim 2, further comprising means. An image processing method for compressing an input image in color space and outputting it to an output device,
A first color space compression step for compressing the input image converted into a device-independent color space within a color reproduction range of an output device of a type different from the output device;
An image processing method comprising: a second color space compression step of compressing the input image color space compressed in the first color space compression step within a color reproduction range of the output device. . The first color space compression step includes
Look-up table generated based on color space compression information of different types of output devices obtained by measuring a color patch printed and output by the different types of output devices by applying a predetermined color space The image processing method according to claim 6, wherein color space compression is performed using an image. The first color space compression step includes
A lookup table generated based on the color space compression information of the different types of output devices obtained by measuring the color patches printed out from the color spaces of the ICC profiles of the different types of output devices. The image processing method according to claim 6, wherein color space compression is performed. The first color space compression step includes
The image processing method according to claim 6, wherein color space compression is performed using a look-up table generated based on output profiles of the different types of output devices. Color space compression information of the different types of output devices obtained by measuring the color patches printed out in the different types of output devices by applying a predetermined color space, and the different types of output devices Holding that holds the color space compression information of the different types of output devices obtained by measuring the color patches printed out from the color space of the ICC profiles that the ICC profile has, and the ICC profiles that the different types of output devices have The image processing method according to claim 7, further comprising a step. A storage medium storing a control program for realizing the image processing method according to claim 6 by a computer. A control program for realizing the image processing method according to claim 6 by a computer.

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