JP2003153020A - Color processor and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of color matching for modifying a color outside a color reproduced region to a color, having a maximum saturation with the same lightness and the same hue, gives a satisfactory result within the color reproduction region but loses image information of colors outside the color reproduced region due to loss of their gradation, etc. SOLUTION: Common color reproduced regions to an input signal and a device are extracted (S302) for mapping color reproduction regions of the input signal, to narrower color reproduction regions of the device, and non-common regions of the input signal, except its common regions, are mapped to remaining regions of the device from which its common regions are removed (S303).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color processing apparatus and method thereof, for example, to color profile creation and color matching.

[0002]

2. Description of the Related Art Color gamuts of color printers differ depending on recording media, and it is impossible to completely match the colors of color images printed on the respective recording media in a colorimetric sense. Therefore, when a human perceives a color image formed on each recording medium, a large difference is felt in the tint between the images.

Gamut compression or gamut compression is used as an image technique for absorbing the difference in perceptual tint of a color image formed between recording media having different color gamuts to achieve perceptual matching of tint. Color matching exists. Various proposals have been made regarding these technologies.
For example, in a uniform color space or HVC color space (a color space consisting of information about lightness, hue, and saturation), it is determined whether or not it is outside the color gamut of the target device / recording medium, There is a method to correct a color so that it has the same lightness and hue and the maximum saturation. In addition, there is also a method of compressing the entire color reproduction area and changing the compression rate according to the area of the color space under the condition that gradation is not lost as much as possible.

There are many color profile creation software programs that use the above techniques. A color profile generally refers to a color attribute file, and is data that is used for calibration of input and output devices and that defines the color attribute of each device.
The color profile of the color printer exists for each type of recording medium so that the same color reproducibility can be obtained regardless of the type of recording medium.

[0005]

However, the above-mentioned method of correcting a color outside the color reproduction range to a color having the same lightness and hue and the maximum saturation gives good results within the color reproduction range. However, with respect to colors outside the color reproduction range, image information is significantly impaired due to loss of gradation and the like.

Further, in the method of compressing the entire color gamut so as not to lose the gradation property as much as possible, colorimetric color difference (color difference) occurs for all colors, so that it is formed on each recording medium. The colors of the color image are observed to be significantly different.

Further, the method of changing the compression rate depending on the area of the color space has a problem that the method of setting the compression rate of each area is complicated.

Furthermore, with existing color profile creation software, in order to obtain information indicating the color reproducibility of the recording medium, it is necessary to print several thousand color patches and measure the color, which is a very laborious task. Required.

The present invention is to solve the above-mentioned problems individually or collectively, and measures the tint of a color image formed on a recording medium of a different type by measuring the color within the color reproduction range of the recording medium. It is an object of the present invention to provide color matching in which a color outside the color reproduction range of the recording medium does not have a loss in gradation and is a color that is perceptually approximate to a color that is approximately similar to a color.

Another object is to easily create a color profile.

[0011]

The present invention has the following structure as one means for achieving the above object.

A color processing apparatus according to the present invention is a color processing apparatus for mapping a first color gamut to a narrower second color gamut, wherein the first and second color gamuts are common. An extraction unit that extracts a region and a mapping unit that maps the first color gamut to a second color gamut, the mapping unit removing the common region from the first color gamut The other area is mapped to the area excluding the common area from the second color reproduction area.

A color processing apparatus for creating a color profile, wherein selection means for selecting an existing color profile as a reference, input means for inputting colorimetric data, selected color profile and input The color gamut of the color profile, and the mapping means for mapping the color gamut of the color profile to the color gamut of the color measurement data, the mapping means, An area excluding the common area from the color reproduction area of the color profile is mapped to an area excluding the common area from the color reproduction area of the colorimetric data.

A color processing method according to the present invention is a color processing method for mapping a first color gamut to a narrower second color gamut, wherein the first and second color gamuts are common. When extracting a region and mapping the first color gamut to the second color gamut, a region excluding the common region from the first color gamut is extracted from the second color gamut. It is characterized in that the area is mapped to an area excluding the common area.

A color processing method for creating a color profile, in which an existing color profile serving as a reference is selected, color measurement data is input, and color reproduction of the selected color profile and the input color measurement data is performed. When extracting a common area of the gamut, when mapping the color gamut of the color profile to the color gamut of the colorimetric data,
An area excluding the common area from the color reproduction area of the color profile is mapped to an area excluding the common area from the color reproduction area of the colorimetric data.

[0016]

DETAILED DESCRIPTION OF THE INVENTION An image processing apparatus according to an embodiment of the present invention will be described in detail below with reference to the drawings.

[0017]

First Embodiment In the first embodiment, an example in which the color matching method of the present embodiment is applied when a color profile is created on each recording medium by a color printer will be described. The type of the color printer is not limited, but the following description will be made assuming that the color printer is an inkjet type color printer.

[Structure] FIG. 1 is a block diagram for explaining image processing, and is a diagram for explaining general image processing performed by a printer driver when a color printer forms a color image on a recording medium. .

The RGB signal converter 101 converts the RGB signal of the input image data into a device RGB signal unique to the printer. The conversion from the input RGB to the device RGB is performed by a three-dimensional lookup table (hereinafter referred to as "3DLUT").

The color separation processing unit 102 separates the device RGB signals into CMYK signals corresponding to the inks of the color printer. Conversion from device RGB to ink CMYK (multi-valued data) is also performed by the 3D LUT.

The binarization processing unit 103 binarizes the CMYK signal (multi-valued data) for each color (channel). CM after binarization
The YK signal (binary data) is transferred to the printer and printing is executed.

[3DLUT] 3D used in the color separation processing unit 102
The LUT exists for each type of recording medium and print mode of the printer, and the 3D LUT is selected according to the information (type of recording medium and print mode) set by the user.

Further, the 3DLU used in the RGB signal converter 101
T is present for each type of recording medium, print mode, matching mode color importance (perceptual), vividness importance (saturation) and faithful reproduction (colorimetric), and information set by the user (recording medium type, 3D LUT is selected according to the print mode and matching mode).

The color profile described in this embodiment is a 3D LUT used in the RGB signal conversion unit 101. Hereinafter, the 3D LUT used in the RGB signal conversion unit 101 is referred to as the “pre-stage LUT”, and the 3D LUT used in the color separation processing unit 102 is referred to as the “post-stage L”.
UT ". FIG. 2 is a diagram schematically showing the pre-stage LUT. For example, when the data is 8 bits, it is a table having N ³ representative points (lattice points) obtained by dividing each RGB axis (0 to 255) into N steps. is there.

Ideally, a color image printed by a color printer should be perceived almost the same regardless of the type of recording medium and the print mode. However, different matching modes have different colors. A device-independent color space (for example, L * a * b *) is used to obtain almost the same color tone regardless of the type of recording medium and print mode.
Set the target value on the color space) and adjust the pre-stage LUT so that the final output approaches the target value.

[Preparation Method of Pre-stage LUT] The preparation method of the pre-stage LUT will be described. First, its preconditions will be described. (1) Target data

A target value (L * a * b * value) corresponding to the RGB value of each grid point is set to each grid point of the preceding LUT. The color reproduction range of this target value is preferably wider than the color reproduction range of any recording medium. (2) Color gamut of recording medium

Information indicating the color gamut of the recording medium for which a color profile is to be created is present in advance.
In order to obtain the color gamut, the front-stage LUT is used as a through-pass, and only the rear-stage LUT is used to print a color patch on the target recording medium for color measurement. Then, the colorimetric data is plotted on the L * a * b * color space, and data representing the color gamut is obtained by interpolation calculation from the data located on the outermost side of the L * a * b * color space. At that time, K ³ color patches in which each RGB axis is divided into K steps are prepared, but it is empirically known that sufficient color matching accuracy can be obtained if K ≧ 9.

FIG. 3 is a flow chart showing a procedure for creating a color profile (pre-stage LUT), and FIG. 4 is a diagram showing an example of brightness compression of target data, where the horizontal axis is the L * value of the target data before compression and the vertical axis is the compression. The L * value of the target data after is shown.

First, the brightness of the target data is compressed according to the color reproduction range of the target recording medium (S301). Specifically, the L * values of the white and black points of the target data are
Make the L * value of the white point and black point of the target recording medium. However, in order to improve the color matching accuracy, the halftone area is not compressed as much as possible. For example, as shown in FIG. 4 as an example, the white point and the black point of the target data indicated by ◯ and ● are divided into six equal parts, and only the two sections of the highest brightness and the lowest brightness of the divided sections are compressed.

Next, a common area of the color reproduction area of the target data and the color reproduction area of the target recording medium is extracted (S30).
2). The extraction method will be described later.

Next, the target data of the area (hereinafter referred to as "non-common area") excluding the common area from the color reproduction area of the target data is compressed (mapped) (S303). The mapping method will be described later. Through the above processing, all target data is mapped within the color reproduction area of the target recording medium.

Subsequently, for all target data, the device RGB value that minimizes the color difference is calculated from the data of the color patch output to the target recording medium (S304).

Extraction Method of Common Area First, target data is classified. The target data exists at N ³ grid points obtained by dividing each RGB axis into N steps, which are classified into (N / 2) groups. To simplify the explanation, the data is 8 bits and each RGB axis is 6
A case where the steps are equally divided will be described. In this case, each RGB value of the grid points is any one of {0, 51, 102, 153, 204, 255}, and the total number of grid points is 216. Such grid points are classified into three groups.

The first group is grid points located on the surface of a hexahedron having the following eight grid points as vertices (FIG. 5A).
reference). (0, 0, 0) (255, 0, 0) (0, 255, 0) (0, 0,
255) (255, 255, 255) (0, 255, 255) (255, 0, 255) (255,
255, 0)

The second group is grid points located on the surface of a hexahedron having the following eight grid points as vertices (FIG. 5B).
reference). (51, 51, 51) (204, 51, 51) (51, 204, 51) (51, 51
51, 204) (204, 204, 204) (51, 204, 204) (204, 51, 204) (20
4, 204, 51)

The third group is grid points located on the surface of a hexahedron having the following eight grid points as vertices (FIG. 5C).
reference). (102, 102, 102) (153, 102, 102) (102, 153, 102) (1
02, 102, 153) (153, 153, 153) (102, 153, 153) (153, 102, 153) (1
53, 153, 102)

As described above, the entire lattice points are regarded as layered hexahedrons. When the grid points are classified as shown in FIG. 5A to FIG. 5C, the target data is located at the position on the L * a * b * color space as shown in FIG.
Note that FIG. 6 (a) shows a state in which the L * a * plane is cut at a certain b * value, and FIG. 6 (b) shows a state in which the a * b * plane is cut at a certain L * value.

Next, it is determined for each classified group whether the target data at each grid point is inside or outside the color reproduction range of the target recording medium. The determination is performed from the outermost side (first group), and a group in which all lattice points of the group are within the color reproduction area (hereinafter referred to as “Mth group”) is searched. When the M-th group is known, it is clear that the area inside the M-th group is within the color reproduction area, so the area inside the M-th group is determined to be the common area.

FIG. 7 is a diagram showing the relationship between the color gamut, the M-th group, and the common area of the target recording medium, with the a * b * plane cut by a certain L * value.

Mapping of Target Data in Non-Common Area Mapping of target data in the non-common area is performed in two steps. The first stage maps the outermost group (first group).

For each target data of the first group, a color having the smallest color difference from the color reproduction range of the target recording medium is calculated, and the L * a * b * value of the color is used as the compressed target data. To do. Normally, the target data of the first group is outside the color gamut of the target recording medium, but after mapping, it will be located on the boundary of the color gamut of the target recording medium.

In the second step, the target data belonging to the M-1th group (one outside the Mth group) from the second group (the second group from the outside) is mapped. This mapping is performed so that each target data is moved between the mapped target data of the first group and the common area while maintaining the positional relationship of each target data before mapping.

FIG. 8 is a flow chart for specifically explaining the second stage mapping.

A database consisting of target data existing in the common area and target data already mapped is created (S801). This database is
Holds the data pair of L * a * b * value before mapping and L * a * b * value after mapping.

The L * a * b * color space is divided into the following eight areas around the target data to be processed (S802). The L * a * b * value of the target data is (Lt, at, bt). Divided area 1: L * ≧ Lt, a * ≧ at, b * ≧ bt Divided area 2: L * ≧ Lt, a * ≧ at, b * <bt Divided area 3: L * ≧ Lt, a * <at, b * ≧ bt Divided area 4: L * ≧ Lt, a * <at, b * <bt Divided area 5: L * <Lt, a * ≧ at, b * ≧ bt Divided area 6: L * <Lt, a * ≧ at, b * <bt Division area 7: L * <Lt, a * <at, b * ≧ bt Division area 8: L * <Lt, a * <at, b * <bt

Data with the smallest color difference from the target data to be processed is searched for in each of the above-mentioned divided areas by referring to the database (S803). That is, eight data surrounding the target data to be processed are searched. However, the color difference is calculated with the L * a * b * value before mapping of the data contained in the database.

When data is searched for in eight divided areas
(S804), the target value after mapping is calculated by interpolation calculation using these eight data (S805). Further, if data is not searched in all of the eight divided areas, interpolation calculation cannot be performed, so the target value after mapping is not set for the time being (S806), and the next target data to be processed is processed.

When the above processing is completed for all target data to be processed (S807) and there is target data for which the target value after mapping is not set (S808), interpolation processing using adjacent target data (mapped) is performed. , Calculate the target value after mapping (S80
9), the process ends.

FIGS. 9A to 9C are diagrams showing a state of mapping of target data, showing a state in which the a * b * plane is cut by a certain L * value. 9A shows before mapping, FIG. 9B shows after first stage mapping, and FIG. 9C shows after second stage mapping.

As described above, according to the first embodiment, the grid points (target data) are classified into layered groups, and the color reproduction area of the target data and the color reproduction area of the target recording medium are classified by the classified groups. Judge the common area,
The target data in the non-common area is moved to the color reproduction area of the target recording medium. Therefore, it is possible to perform color matching in which the colorimetrical matching is performed in the common area and the non-common area is perceptually approximated without crushing the gradation.

[0052]

[Second Embodiment] An image processing apparatus according to a second embodiment of the present invention will be described below. In the present embodiment,
About the same configuration as that of the first embodiment, the same reference numerals are given and the detailed description thereof is omitted.

The second embodiment is a modification of the common area extraction method of the first embodiment. In the first embodiment, the grid points (target data) of the 3DLUT are classified into layered groups to extract the common area. Therefore, 3DLUT
If the grid points of are coarsely spaced, there is a possibility that the common area, which should originally be a little wider, becomes narrower. In such cases,
Even in the area where colorimetric matching is originally possible, the target data is mapped, resulting in a decrease in color matching accuracy. Therefore, in the second embodiment, the common area is extracted so that the widest common area is extracted.

[Extraction of Common Area] Up to the step of obtaining the M-th group of common areas is the same as in the first embodiment,
The description is omitted.

FIG. 10 is a flow chart showing a method of extracting a common area that is as wide as possible and that is similar in part or in whole to the shape of the color reproduction area of the target data. The largest group in the common area (Mth group)
Group) is called the Max layer, and the group with the smallest width in the non-common area (M-1th group) is called the Min layer.

First, it is judged whether or not the Max layer and the Min layer can be divided (S1001). If the division is possible, a new layer (group, "Neo layer") is provided between the Max layer and the Min layer. Is called) (S1002). The Neo layer has the same number of target data as the Min layer.

Next, it is determined whether all the target data of the Neo layer are within the color reproduction range of the target recording medium (S
1003), if all of the target data is within the color reproduction range of the target recording medium, the Neo layer indicates the common area, and since it is the layer with the maximum width within the common area, the Neo layer is the Max layer (S10
04), and returns the process to step S1001. The previous Max layer (group) is the M + 1th group.

On the other hand, when the target data is outside the color reproduction range of the target recording medium, the Neo layer is the layer with the smallest non-common area, so the Neo layer is set as the Min layer (S1005), and the processing is performed. Return to S1001. The previous Min layer (group)
Will be group M-2.

If the Max layer and the Min layer cannot be divided, the current Max layer is set as the largest layer in the common area, and the inside of the Max layer is set as the common area (S1006).

According to the processing shown in FIG. 10, a new layer is created between the Min layer and the Max layer, and a new group (New layer) lattice is added to the common area group or the non-common area group. The process of adding points (target data) is Min
Iterate until the layers and Max layers become indivisible.

As described above, according to the second embodiment, a layer having the largest width in the common area and a layer having the smallest width in the non-common area are divided to create a new layer. In other words, by recursively creating a new layer and updating the common area, it is possible to extract a common area that is as wide as possible and that is partially or wholly similar to the shape of the color reproduction area of the target data. Therefore, it is possible to perform more accurate color matching.

[0062]

Third Embodiment An image processing apparatus according to the third embodiment of the present invention will be described below. In the present embodiment,
About the same configuration as that of the first embodiment, the same reference numerals are given and the detailed description thereof is omitted.

[Color Profile Creation Software] FIG. 11 is a diagram showing an example of a user interface (screen) of the color profile creation software.

When the standard color profile button 301 is pressed, a file selection dialog is displayed, and the standard color profile stored in a memory such as a hard disk can be selected. Then, the display unit 302 displays the file name of the selected reference color profile.

When the color measurement file button 303 is pressed, a file selection dialog is displayed, and a color measurement data file stored in a memory such as a hard disk can be selected. Then, the display unit 304 displays the file name of the selected color measurement data file. The colorimetric data is recorded on the recording medium for which the color profile is created.
This is data obtained by printing a color patch having a specified RGB value by using the front LUT as a through-pass and using the rear LUT, and measuring the color of the printed color patch with a colorimeter. This data is device-independent color space data, here L * a *
b * Color space data. As mentioned above, RGB
It is known that if there are 9 or more step K dividing each axis, it is enough to grasp the color reproducibility, so 9 ³ = 729
We will print out individual color patches and measure them.

When the create profile button 305 is pressed, a file save dialog is displayed, and a path name or file name for saving the created color profile in a memory such as a hard disk can be selected or designated. Then, the display unit 306 displays the designated (selected) path name and file name.

When the create button 307 is pressed, creation of the color profile is started, and when the end button 308 is pressed, the color profile creating software is ended.

[Color Profile Creating Process] FIG. 12 is a flowchart showing an example of the color profile creating process, which is a process executed by the above-mentioned color profile creating software.

First, the color gamut of the recording medium for which a color profile is to be created is calculated (S401). That is, the color measurement data read from the selected color measurement data file is L * a * b *
Data indicating the color gamut of the recording medium is calculated by plotting in the color space and performing interpolation calculation using the outermost data.

The following processing is performed in step S301 shown in FIG.
Since it is the same as the process from S304 to S304, detailed description thereof will be omitted, but as described in the first embodiment, common area extraction, and by mapping the target data of the non-common area, for all target data, The device RGB value that minimizes the color difference is calculated from the data of the color patch output to the target recording medium (S304).

As described above, according to the third embodiment, the grid points (target data) of the reference color profile are classified into layered groups, and the color reproduction area of the target data and the target recording medium are classified according to the classified groups. The common area of the color reproduction area is determined, and the target data of the non-common area is moved to the color reproduction area of the target recording medium. Therefore, it is possible to easily create a color profile that retains the color reproducibility of the selected reference color profile and has no gradation loss even in the high saturation region.

If the common area extraction method described in the second embodiment is used so that the widest common area can be extracted, the widest common area and
It is possible to create a high-accuracy color profile by extracting a common region that is partially or wholly similar to the shape of the color reproduction area of the target data and has a wider area in which colorimetric matching is possible.

[0073]

[Fourth Embodiment] An image processing apparatus according to a fourth embodiment of the present invention will be described below. In the present embodiment,
The same components as those in the first to third embodiments are designated by the same reference numerals, and detailed description thereof will be omitted.

In the fourth embodiment, a matching accuracy setting function of a color profile to be created is added to the user interface shown in FIG. 11, and target data is divided into layers according to the set matching accuracy. Change the interval.

FIG. 13 is a diagram showing an example of a user interface (screen) of the color profile creation software of the fourth embodiment, in which a radio button 309 for setting the matching accuracy is added. FIG. 13 shows an example in which either “standard” or “high accuracy” can be selected as the matching accuracy, but “highest accuracy” or the like may be selected.

FIG. 14 is a flowchart showing an example of the color profile creation processing of the fourth embodiment, which is the processing executed by the above-mentioned color profile creation software.

First, the target data of the reference color profile is recreated (S501). However, the target data to be recreated differs depending on the set matching accuracy. The data is 8 bits.

When "standard" is selected as the matching accuracy, 16 ³ = 4096 grid points, which are obtained by equally dividing each RGB axis into 16 steps, are created as grid points of the 3DLUT. Then, the target data to be recreated is calculated by the interpolation calculation using the target data of the reference color profile. In this case, the RGB value of the grid point is {0, 17, 34, 51, 68, 85,10
It will be one of 2, 119, 136, 153, 170, 187, 204, 221, 238, 255}. Since it is divided into 16 steps, the target data is divided into 8 groups (layers).

On the other hand, when “high accuracy” is selected as the matching accuracy, 33 ³ = 35937 grid points are created as grid points of the 3DLUT by equally dividing each RGB axis into 33 steps. Then, the target data to be recreated is calculated by the interpolation calculation using the target data of the reference color profile. In this case, the RGB value of the grid point is {0, 8, 16, 24,3
2, 40, 48, 56, 64, 72, 80, 88, 96, 104, 112, 120,
128, 136, 144, 152, 160, 168, 176, 184, 192, 200, 2
It will be one of 08, 216, 224, 232, 240, 248, 255}.
Since it is divided into 33 steps, the target data is divided into 16 groups (layers), and the spacing between layers is narrower than in the case of “standard”.

The following processing is performed in step S401 shown in FIG.
Since it is the same as the processing from S301 to S304, detailed description thereof will be omitted. However, as described in the first embodiment, by extracting the common area and mapping the target data in the non-common area, all target data For, the device RGB value that minimizes the color difference is calculated from the data of the color patch output to the target recording medium (S304).

As described above, according to the fourth embodiment, the interval between layers for dividing the target data is changed according to the matching accuracy of the color profile that is set.

When "high precision" is set, the space between layers can be narrowed to extract the common region more accurately, and as a result, a color profile capable of highly accurate color matching can be created. It However, if "high accuracy" is set, the number of divisions increases, and naturally, the number of data also increases, the data size of the color profile increases, and the creation time also increases. So in a short time, and /
Alternatively, if you want to create a color profile with a small data size, you can set "standard".

[0083]

Other Embodiments Even when the present invention is applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), an apparatus including one device (for example, a copying machine). Machine, facsimile machine, etc.).

The object of the present invention is to supply a storage medium (or recording medium) recording a program code of software for realizing the functions of the above-described embodiments to a system or apparatus, and to supply the computer of the system or apparatus ( Needless to say, this can also be achieved by the CPU or MPU) reading and executing the program code stored in the storage medium. 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. Also,
By executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an operating system (OS) running on the computer based on the instructions of the program code.
Needless to say, this also includes the case where the above-mentioned processes perform part or all of the actual processing and the functions of the above-described embodiments are realized by the processing.

Further, after the program code read from the storage medium is written in the memory provided in the function expansion card inserted into the computer or the function expansion unit connected to the computer, based on the instruction of the program code. Needless to say, this also includes a case where a CPU or the like included in the function expansion card or the function expansion unit performs a part or all of the actual processing and the processing realizes the functions of the above-described embodiments.

When the present invention is applied to the above storage medium, the storage medium stores the program code corresponding to the above-described flowchart.

[0087]

As described above, according to the present invention,
Color tones of color images formed on recording media of different types are colorimetrically similar to those in the color reproduction range of the recording medium, and colors outside the color reproduction range of the recording medium have no loss of gradation. In addition, it is possible to provide color matching that makes the colors perceptually similar.

Also, a color profile can be easily created.

[Brief description of drawings]

FIG. 1 is a block diagram for explaining image processing,

FIG. 2 is a diagram schematically showing a pre-stage LUT,

FIG. 3 is a flowchart showing a procedure for creating a color profile (pre-stage LUT),

FIG. 4 is a diagram showing an example of lightness mapping of target data;

FIG. 5 is a diagram illustrating classification of grid points;

FIG. 6A is a diagram illustrating classification of grid points;

FIG. 6B is a diagram illustrating classification of grid points;

FIG. 6C is a diagram illustrating classification of grid points;

FIG. 7 is a diagram showing a relationship between a color gamut, a Mth group, and a common area of a target recording medium,

FIG. 8 is a flowchart specifically illustrating a second-stage mapping,

FIG. 9A is a diagram showing how target data is mapped,

FIG. 9B is a diagram showing how target data is mapped;

FIG. 9C is a diagram showing how target data is mapped,

FIG. 10 is a flowchart showing a method for extracting a common area,

FIG. 11 is a diagram showing an example of a user interface of color profile creation software;

FIG. 12 is a flowchart showing an example of color profile creation processing,

FIG. 13 is a diagram showing an example of a user interface of color profile creation software;

FIG. 14 is a flowchart illustrating an example of color profile creation processing.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takuya Shimada             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation (72) Inventor Hirochika Matsuoka             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation (72) Inventor Yuji Akiyama             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation (72) Inventor Makoto Torigoe             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation F-term (reference) 2C262 AA02 AA24 AB12 BA02 BC01                       BC13 BC19 EA13                 5B057 AA11 CA01 CA08 CA12 CA16                       CB01 CB08 CB12 CB16 CE17                       CE18 DA17 DB02 DB06 DB09                       DC25                 5C077 LL01 MP08 PP32 PP33 PP36                       PP37 PQ23 RR02 TT02                 5C079 HB01 HB03 HB08 HB12 LA23                       LB02 MA04 NA03

Claims (10)

[Claims] 1. A color processing device for mapping a first color gamut to a narrower second color gamut, and an extraction means for extracting a common area of the first and second color gamuts. A mapping unit that maps the first color gamut to a second color gamut, wherein the mapping unit is an area obtained by removing the common area from the first color gamut to the second color gamut. A color processing apparatus, wherein the color reproduction area is mapped to an area excluding the common area. 2. A color processing apparatus for creating a color profile, comprising: selecting means for selecting an existing color profile as a reference; input means for inputting colorimetric data; and the selected color profile and the input Extraction means for extracting a common area of the color gamut of the colorimetric data, mapping means for mapping the color gamut of the color profile to the color gamut of the colorimetric data, the mapping means, A color processing apparatus, wherein an area excluding the common area from a color reproduction area of a color profile is mapped to an area excluding the common area from the color reproduction area of the colorimetric data. 3. A color processing method for mapping a first color gamut to a narrower second color gamut, wherein a common area of the first and second color gamuts is extracted, When mapping one color gamut to the second color gamut, the area excluding the common area from the first color gamut, the area excluding the common area from the second color gamut To the color processing method. 4. A color processing method for creating a color profile, wherein an existing color profile serving as a reference is selected, color measurement data is input, and the color reproduction of the selected color profile and the input color measurement data is performed. When extracting the common area of the color profile and mapping the color reproduction area of the color profile to the color reproduction area of the colorimetric data, the area excluding the common area from the color reproduction area of the color profile is measured. A color processing method, wherein mapping is performed from a color reproduction area of color data to an area excluding the common area. 5. The shape of the boundary of the common area is partially or wholly similar to the shape of the boundary of the first color gamut. Color processing method. 6. The common area is extracted by dividing the first color gamut into a plurality of layered areas and comparing the divided layered areas with the second color gamut. 6. The color processing method according to any one of claims 3 to 5. 7. The mapping is performed by dividing an area obtained by removing a common area from the first color reproduction area into one or a plurality of layered areas and adaptively dividing the divided layered areas into the second color. 4. Mapping within the reproduction range
7. The color processing method according to claim 6. 8. The common area is recursively divided between a layered area determined to be located on the outermost side of the common area and a layered area adjacent to the layered area and located on the outer side. The color processing method according to claim 3, wherein the color processing method is updated. 9. A program which controls an information processing device to execute the color processing according to claim 3. Description: 10. A recording medium on which the program according to claim 9 is recorded.