JP2006287584A - Image processing method, image processor and image processing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processing method, image processor and image processing system for performing color gamut compression with gradations maintained in order to realize common color reproduction between a first device and a second device having a color reproduction ranges different from each other. <P>SOLUTION: In a step S204, color gamut compression in which colors within color reproduction ranges between devices are made to correspond to each other is performed. In a step S207, a color distribution of outermost colors of the color reproduction range in a first device and a color distribution of outermost colors of the color reproduction range of a second device are set so as to make them show relatively similar color reproducibility, and color gamut compression in which the outermost colors of the color reproduction ranges between the devices is performed on the basis of the color distributions of the outermost colors. In a step S208, a color conversion table is prepared on the basis of respective color gamut compression results within the the color reproduction ranges and the outermost colors. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image processing method, an image processing apparatus, and an image processing system, and in particular, an image processing method and an image processing apparatus that perform color gamut conversion of an image to obtain similar color reproducibility between a plurality of apparatuses, and The present invention relates to an image processing system.

  Generally, in a device that handles a color image, the color gamut shape varies from device to device. For example, the color gamut of the monitor depends on the type of phosphor used, because color reproduction is performed by additive color mixing by the development of phosphors of the three primary colors of red (R), green (G), and blue (B). . On the other hand, the color gamut of the printer differs depending not only on the ink used but also on the type of paper. FIG. 16 shows an example of the color gamut of the sRGB monitor and the ink jet printer. The figure compares two color gamuts on the L * C * plane, which is converted from the color signal value L * a * b * in the CIELAB color space using the following equations (1) and (2). It is.

L * = L * (1)
C * = ((a *) 2+ (b *) 2) 1/2 ... (2)
In the hue shown in FIG. 16, in the color gamut of the inkjet printer, it can be seen that the peak of saturation (C *) is shifted in the lightness (L *) direction in the low lightness direction compared to the monitor color gamut.

  Thus, when the output color gamut is smaller than the input color gamut, it is impossible to accurately reproduce the input color information depending on the image. For example, when an image on a monitor is output by a printer, since the color gamut of the printer is generally smaller than that of the monitor, colors outside the color gamut of the printer cannot be reproduced as they are.

  Therefore, in such a case, it is necessary to perform color processing that keeps the original image information as much as possible and keeps colors outside the color gamut within the color gamut. In this way, pushing a color that cannot be reproduced in the device into a color gamut that can be reproduced by performing some kind of processing is generally called color gamut compression.

In addition, comparing the saturation range of the monitor and the printer in FIG. 16, it can be seen that the saturation range of the printer is narrower, but absorbing this difference in saturation range also has a large gamut compression. One of the challenges. Therefore, for example, a method of compressing colors with high saturation in high brightness and low brightness areas by making the convergence point for determining the compression direction in color gamut compression into a chromatic color (see, for example, Patent Document 1), etc. Various proposals have been made.
JP 2000-341548

  However, in the color gamut compression method shown in Patent Document 1, although high saturation is realized in the low lightness region and high lightness region, it is impossible to control the high saturation in the intermediate lightness region, so that gradation is lost as a result. There was a case. In addition, with only compression toward the convergence point, the reproduced color depends on the shape of the input color gamut and the output color gamut, so saturation adjustment cannot be performed and it is impossible to perform color adjustment desired by the user.

  The present invention has been made in order to solve the above-described problem, and in order to realize a common color reproduction between the first apparatus and the second apparatus having different color reproduction ranges, a color with gradation maintained. An object of the present invention is to provide an image processing method, an image processing apparatus, and an image processing system that perform area compression.

  It is another object of the present invention to provide an image processing apparatus and method capable of adjusting saturation at the time of color gamut compression.

  The present invention has been made in order to solve the above-described problem, and in order to realize a common color reproduction between the first apparatus and the second apparatus having different color reproduction ranges, a color with gradation maintained. An object of the present invention is to provide an image processing method, an image processing apparatus, and an image processing system that perform area compression.

  It is another object of the present invention to provide an image processing apparatus and method capable of adjusting saturation at the time of color gamut compression.

  As a technique for achieving the above object, the image processing method of the present invention includes the following steps.

  That is, color conversion using a table is performed on the image signal input from the first device between the first device and the second device having different color reproduction ranges, and the second device is subjected to color conversion. An image processing method for output, the color gamut compression step for performing color gamut compression in which a color in the color reproduction range in the first device is associated with a color in the color reproduction range in the second device; The first outermost color distribution setting step for setting the color distribution of the outermost color in the color reproduction range in the first device, and the color distribution of the outermost color in the color reproduction range in the second device are set. Based on the color distribution of the respective outermost colors set in the second outermost color distribution setting step and the first and second outermost color distribution setting steps, the maximum color reproduction range in the first device. Outer color and the second device The outermost color gamut compression step for performing color gamut compression corresponding to the outermost color in the color reproduction range, and the table based on the color gamut compression results obtained by the intra-gamut compression step and the outermost color gamut compression step. And a table creation step to be created.

  More specifically, in the second outermost color distribution setting step, the color distribution of the outermost color in the second device is the first outer color set in the first outermost color distribution setting step. It is characterized in that the color reproducibility is set relatively similar to the color distribution of the outermost color in the apparatus.

  Furthermore, it has a saturation adjustment step of changing the brightness and saturation in the second device based on a user instruction, and in the second outermost color distribution setting step, the brightness adjusted in the adjustment step again The color distribution of the outermost color in the color reproduction range in the second apparatus is set based on the saturation and the saturation.

  Further, the image processing apparatus further includes a color gamut shape determining step for determining a size ratio of a color reproduction range in the first device and the second device, and in the second outermost color distribution setting step, the size ratio is set to the size ratio. Based on this, the color distribution of the outermost color of the color reproduction range in the second apparatus is set.

  According to the present invention, between the first device and the second device having different color reproduction ranges, gradation is taken into consideration within the color reproduction range, and the outermost color is emphasized in saturation, so that gradation can be obtained. It is possible to easily create a table for performing color gamut conversion while maintaining common color reproduction.

  Further, by providing a function for adjusting the color distribution of the outermost color, it is possible to easily adjust the saturation.

  Hereinafter, the present invention will be described in detail based on preferred embodiments with reference to the accompanying drawings.

<First Embodiment>
Image Processing System FIG. 1 is a block diagram showing the configuration of an image processing apparatus that is an embodiment according to the present invention. In the figure, 1 is an image processing apparatus according to the present embodiment, 2 is an image display apparatus for displaying an image such as a monitor, and 3 is an image output apparatus for outputting an image such as a printer.

  In the image processing apparatus 1, 4 is an image display unit that generates a signal for display on the image display apparatus 2, and 5 is a gradation conversion process for outputting the color displayed on the image display apparatus 2 to the image output apparatus 3. An image processing unit 6 that performs the above and the like is a target color storage unit that stores printer gamut information that is stored in the printer profile 13 and that is a target for printer color reproduction. In the present embodiment, a color reproducible range (color reproduction range) is referred to as a color gamut. 7 is an in-gamut color compression processing unit that performs gamut compression on the in-gamut colors among the target colors stored in the target color storage unit 6, and 8 is a target color stored in the target color storage unit 6. A color gamut outermost compression processing unit that performs color gamut compression on the color gamut outermost color, and 9 sets the color signal distribution of the color gamut outermost color among the color signal values output by the image output device 3. This is a color gamut outermost color distribution setting unit.

  Further, 10 is an image output unit that generates a signal to be output by the image output device 3, 11 is a data buffer that temporarily stores data for data processing, and 12 is a monitor profile of the image display device 2 or the like. Monitor profile to be stored, 13 is a printer profile storing a printer profile such as the image output device 3, 14 is a UI unit for the user to operate using the image processing device 1, and 15 is the image output device 3 A color conversion processing unit that performs color conversion processing for output to the LUT using a LUT, 16 is a color that creates a color matching LUT between the color displayed on the image display device 2 and the color output on the image output device 3 LUT creation part. In the present embodiment, the color conversion processing unit 15 refers to the LUT created by the color LUT creation unit 16.

Overall Processing Hereinafter, the color gamut compression processing performed in the image processing apparatus 1 of the present embodiment will be described with reference to FIGS. FIG. 2 is a flowchart showing color gamut compression processing performed in the image processing apparatus 1, and FIG. 3 is a diagram showing an example of a user interface (UI) for the processing.

  The flowchart shown in FIG. 2 is started when the UI 501 shown in FIG. 3 is operated. Specifically, the following operations are performed on the UI 501.

  First, the user operates pull-down menus 502 and 503 to perform desired output device settings and output paper settings. Next, the user presses the reference button 504 to set the target color, selects a target color file that is a target of color reproduction of the LUT created in the present embodiment, and sets it in the target color storage unit 6 .

  Here, the target color is set as an Lab value for each of the 9 levels of RGB data (total 729 colors) used in the image processing of the present embodiment.In this embodiment, as shown in FIG. As a file, it is prepared in advance in HD (not shown). In this embodiment, since an example of creating an LUT having nine grid points as a color matching LUT will be described, the target color file selected here has target color data for nine stages of RGB (729 colors). Suppose you are. That is, here, the target color file may be selected according to the scale of the LUT to be created.

  Finally, when the user presses the LUT creation button 505, the color gamut compression processing of this embodiment is started.

  In FIG. 2, first, in step S201, the number of colors N as a counter is initialized to zero. In step S202, the target color data R of the Nth color is acquired from the target color file set in the UI shown in FIG. In step S203, it is determined whether or not the target color data R acquired in step S202 is the outermost contour of the target color. If it is the outermost contour, the process proceeds to step S205, and if not, the process proceeds to step S204. Here, the determination of whether or not the color gamut is the outermost contour of the target color is focused on the RGB value corresponding to the target color data R acquired in step S202, and at least one of the R, G, and B color signals Can be based on whether is 0 or 255. That is, if any one of the R, G, and B values is 0 or 255, the target color data R is determined to be the outermost contour.

  In step S204, the color gamut compression processing of the color gamut is performed in the color gamut color compression processing unit 7, and in step S205, the outermost color is further sorted and stored in a predetermined buffer area on the predetermined data buffer 11. Details of each of these processes will be described later.

  When the in-gamut color compression processing in step S204 or the outermost color storage processing in S205 ends, it is determined in step S206 whether the number of colors N is less than 729. If the number of colors N is less than 729, step S208 is performed. If the number N of colors is 729 or more, the process proceeds to step S207. In the present embodiment, 729 is described as the threshold value for the number of colors N, but the present invention is not limited to this example, and the threshold value is determined according to the number of grid points of the LUT created in step S208.

  In step S207, the color gamut outermost compression processing unit 8 performs color gamut compression processing on the outermost color data stored in the buffer in step S205. This will be described in detail later.

  In step S208, the color LUT creation unit 16 creates color matching LUTs for all target colors based on the color gamut compression results in steps S204 and S207. Here, since the number of grid points of the LUT is 9 in the present embodiment, the calculation result of the L * a * b * value after color gamut compression in step S204 and the color in step S207 for each of nine stages of RGB (729 colors) Table data is created based on the L * a * b * value calculation results after area compression.

Outermost Color Storage Processing Hereinafter, the outermost color storage processing in step S205 will be described in detail using FIG. 4 and FIG. FIG. 4 is a flowchart showing the outermost color storing process, and FIG. 5 is a diagram showing a WP-Bk (white-primary-black) line. In this embodiment, in the color gamut compression between the compression source target color R and the compression destination output media reproduction color X, the hue angle of the compression destination reproduction color X is the hue of the compression source target color R. The corner shall be used as it is.

  First, in step S301, it is determined whether or not the compression target color data R is a color signal value on the W-P-Bk line. Here, the WP-Bk line is a line indicating the color transition of white-primary color-black on the lightness-saturation plane, and is indicated by the L * a * b * values for the RGB values as shown in FIG. . In FIG. 5, j indicates each primary color, and for example, a column of j = 0 indicates a red (red phase) W-P-Bk line. Similarly, j = 1 represents green, j = 2 represents blue, j = 3 represents cyan, j = 4 represents magenta, and j = 5 represents yellow. That is, in step S301, it is determined more strictly whether the target color data R is the outermost color by determining whether the target color data R is on the W-P-Bk line.

  If the target color data R is the outermost color on the W-P-Bk line in step S301, the process proceeds to step S302, and the target color data R is written in the buffer area B provided in the data buffer 11. Hereinafter, the target color data written in the buffer area B is referred to as W-P-Bk line data. On the other hand, if the target color data R is not on the W-P-Bk line, the process proceeds to step S303, and the target color data R is written in the buffer area A provided in the data buffer 11. Hereinafter, the target color data written in the buffer area A is referred to as W-P-Bk out-of-line data.

  As described above, according to the outermost color storage process in step S205, the data on the WP-Bk line and the data outside the WP-Bk line are further added to all target color data determined as the outermost color in step S203. Sorting is performed. The sorted outermost data is a processing target in the outermost color compression processing in step S207.

Outermost Color Compression Processing Hereinafter, the outermost color compression processing in step S207 will be described in detail with reference to FIG. 6 and FIG. FIG. 6 is a flowchart showing outermost color compression processing, and FIG. 7 is a diagram for explaining a color gamut compression method in the outermost color gamut.

  The data on the W-P-Bk line and the data outside the W-P-Bk line are allocated to the buffer area B and the buffer area A, respectively, by the outermost storage process in step S205 described above. Here, color gamut compression processing is first performed on the data on the WP-Bk line stored in the buffer area B in steps S304 to S310.

  First, in step S304, a variable j as a counter indicating the primary color is initialized to zero. As can be seen from FIG. 5 described above, in this embodiment, j takes a value from 0 to 5. By setting this counter j, the L * a * b * value for a specific RGB value can be acquired from the target color data R input to the outermost color compression processing in step S205. Specifically, as shown in FIG. 5, for example, by setting j = 0, it is possible to perform processing for the outermost color in the red phase in the outermost target color data R.

  In step S305, the color distribution information of the outermost color of the target color is calculated using the data on the W-P-Bk line stored in the buffer area B. Details of this processing will be described with reference to FIGS. FIG. 7 shows a lightness-saturation plane at a certain hue angle, and particularly shows the outermost color (C0 to C16) of the input medium and the outermost color (A0 to A16) of the output medium. Also, the outermost color connecting the primary color (C8) of the input media and paper white (C0) is the white-primary line (hereinafter referred to as WP line) of the input media, and the line connecting the primary color (C8) and black (C16). Is the primary-black line (hereinafter referred to as P-Bk line) of the input medium. The outermost color distribution of the target color is calculated by dividing it into two types: W-P line and P-Bk line.

  First, the color distribution of the W-P line is calculated using the path Sc from C0 to C8. Sc can be expressed as a sum of distances between adjacent color signal values such as C0 and C1. Further, for example, in the case of Sc2, the path Sci in each color signal value is obtained as the sum of the distance between C0 and C1 and the distance between C1 and C2. Specifically, the color distribution of the WP line can be expressed as a distance from C0 in each color signal value (distance is normalized so that Sc8 is 1) as shown in FIG.

  Note that the color distribution of the P-Bk line is also calculated using the color signal values of C8 to C16, as in the above-described method for calculating the color distribution of the WP line.

  Next, in step S306, the color distribution of the outermost color of the output medium for outputting the target color is calculated. As for the outermost color of the output media, the outermost color connecting the primary color (A8) and paper white (A0) shown in FIG. The line connecting the primary color (A8) and black (A16) is defined as the P-Bk line of the output medium.

  Details of the outermost color distribution calculation process of the output medium in step S306 will be described with reference to FIG. Figure 9 shows the color distribution of the output media that should correspond to the input media, that is, the color distribution of the target color (the distance from the primary color (C8) of the input media to paper white (C0) is normalized to 1). The distance from the primary color (A8) to the paper white (A0) is normalized to 1). In the present embodiment, as shown in the figure, the outermost color distribution of the output medium is calculated so that the color distribution of the output medium shows a similar reproducibility relative to the color distribution of the input medium.

  Next, in step S307, the primary color of the output medium is calculated. That is, a color that minimizes the distance in the lightness and saturation direction of the primary color of the input medium with respect to the outermost color of the output medium obtained in step S306 is set as the primary color of the output medium.

  In step S308, a reproduction color in the outermost contour of the output medium is calculated based on the color distribution of the outermost contour color of the output medium obtained in step S306 and the primary color of the output medium obtained in step S307.

  Through the processes in steps S305 to S308 described above, the outermost reproduced color of the output medium in j = 0, that is, the red phase is calculated.

  In step S309, the value of j is determined. If j is less than 6, it is determined that there is an unprocessed hue, the process proceeds to step S310, the variable j is incremented, the process returns to step S305, and the process for the next hue is started. On the other hand, if j is 6 or more in step S309, it is determined that the processing for all hues has been completed, and the process proceeds to step S311.

  With the above processing, the outermost reproduced color of the output medium is calculated for the data on the W-P-Bk line for all hues, that is, the target for color gamut compression is calculated.

  In step S311, data outside the W-P-Bk line, which is target color data that is not on the W-P-Bk line, stored in the buffer area A is read, and a reproduced color on the output medium is calculated. In other words, the data outside the WP-Bk line is reproduced by interpolation processing based on the relationship between the outermost color reproduction of the output media on the WP-Bk line calculated in step S308 and the target color on the WP-Bk line of the input media. Calculate the color.

  With the above processing, the reproduction color in the output medium is calculated for the data on the WP-Bk line and the data outside the WP-Bk line, that is, the outermost color is determined in step S203, and either buffer area A or B is determined in step S205. With respect to all the target color data distributed to each other, reproduced colors after color compression are calculated. By performing such color compression for all the target colors in the outermost contour, color reproduction with improved saturation is possible.

Intra-gamut Color Compression Processing Hereinafter, intra-gamut color compression processing in step S204 will be described in detail with reference to FIG. 10 and FIG. FIG. 10 is a flowchart showing the color gamut color compression processing, and FIG. 11 is a diagram for explaining a color gamut compression method in the color gamut. In the intra-gamut color compression process, as in the outermost color compression process described above, the hue angle of the reproduction color X to be compressed uses the hue angle of the target color R as the compression source as it is.

  First, in step S401, the outermost line Po in the color gamut of the output medium is obtained from the printer profile 13, and in step S402, the outermost line Ro of the target color data R (W-P-Bk line shown in FIG. 5) is obtained.

  In step S403, a line segment lc connecting the target color data R and the fixed point Lst (in this embodiment, L * = 50.0 on the L * axis) is calculated, and in step S404, the line segment lc and The intersection point Q with the outermost line Ro of the target color is calculated. In step S405, the intersection point P between the line segment lc and the output printer color gamut outermost line Po is calculated. In step S406, the distance Sin_max between the fixed point Lst and the intersection point Q is calculated. The distance Sin with the data R is calculated.

  Next, in step S408, Sstd_in obtained by normalizing Sin with Sin_max is calculated using the following equation (3).

Sstd_in = Sin / Sin_max (3)
In step S409, a distance Sout_max between the fixed point Lst and the intersection point P is calculated, and in step S410, a distance Sout between the fixed point Lst and the reproduction color data X of the output printer is calculated.

  In step S411, Sstd_out_max obtained by normalizing Sout_max using Sout and Sin_max is calculated. In step S412, Sstd_out obtained by normalizing Sout using Sin_max is calculated based on equations (4) and (5). .

When Sin <Sin_max x 0.8
Sstd_out = Sstd_in (4)
When Sin ≧ Sin_max × 0.8
Sstd_out = T × std_in + 0.8 × (1-T) (5)
Where T = (Sstd_out_max-0.8) / (1-0.8)
FIG. 12 shows a specific example of Sstd_out calculated in step S412. According to the figure, it can be seen that the slope of Sstd_out changes with Sstd_in = 0.8 as a boundary. This is because the above equation (4) is applied while Sstd_in <0.8, and the above equation (5) is applied when Sstd_in ≧ 0.8. In this embodiment, “0.8” is used for the case classification of Sin (Sstd_in) when calculating Sstd_out. However, the present invention is not limited to this and can be changed as necessary.

  When the normalized Sstd_out is obtained as described above, in step S413, the distance Sout between the fixed point Lst and the reproduced color X of the output printer is calculated by the following equation (6).

Sout = Sstd_out × Sin_max (6)
Finally, in step S414, the reproduction color X of the output printer is calculated using Sout and the line segment lc.

  With the above processing, for all target color data input to the in-gamut color compression processing in step S204, reproduced colors after color compression are calculated. By performing such color compression on the target color in the color gamut, color reproduction considering gradation can be performed.

As described above, according to the present embodiment, the target color is divided into the in-gamut color and the outermost color, and the color compression processing is performed. In the outermost color, saturation can be increased.

  Therefore, it is possible to easily create a color conversion table in which saturation is emphasized while maintaining gradation, and by performing color conversion using the color conversion table, a common gradation is maintained between the input medium and the output medium. Color reproduction can be realized.

Second Embodiment
Hereinafter, a second embodiment according to the present invention will be described. The system configuration in the second embodiment is the same as that of the first embodiment described above, and a description thereof will be omitted.

  In the first embodiment described above, in the outermost color compression processing described using the flowchart of FIG. 4, the relationship between the color distribution of the outermost color in the target color and the color distribution of the outermost color in the output medium is relatively equal. An example was given. The second embodiment is characterized in that saturation adjustment is realized by allowing the user to arbitrarily set the color distribution relationship.

  In the second embodiment, a UI as shown in FIG. 13 is provided in addition to the first embodiment described above, and the user arbitrarily adjusts the saturation by operating the mouse. FIG. 13 shows the relationship of the color distribution of the WP line of the output medium with respect to the color distribution of the target color of the WP line, and corresponds to FIG. 9 shown in the first embodiment. In the second embodiment, in the UI of FIG. 13, when the user operates the mouse to make the graph shape convex downward, the saturation is emphasized, and when the graph shape is convex upward, the saturation is suppressed. It becomes possible to manipulate the degree arbitrarily.

  As described above, according to the second embodiment, in addition to the first embodiment described above, by providing a function for adjusting the color distribution of the outermost color, it is easy to adjust the saturation as desired by the user. It can be carried out.

<Third Embodiment>
The third embodiment according to the present invention will be described below. The system configuration in the third embodiment is the same as that in the first embodiment described above, and a description thereof will be omitted.

  In the first embodiment described above, in the outermost color compression processing described using the flowchart of FIG. 4, the relationship between the color distribution of the outermost color in the target color and the color distribution of the outermost color in the output medium is relatively equal. An example was given. In the third embodiment, as shown in FIG. 14, the ratio of the color gamut size (Ai) of the input medium to the color gamut size (Bi) of the output medium (C = {(A1 / B1 + A2 / B2 + ... An / Bn) / n} (hereinafter referred to as color gamut ratio C)), the outermost color distribution of the input media and the outermost color distribution of the output media are automatically set. And

  Here, the relationship between the outermost color distribution X of the input medium and the outermost color distribution Y of the output medium is expressed by the following equation (7) using the γ value.

Y = γX (7)
FIG. 15 shows the γ value according to the equation (7) with respect to the color gamut ratio C set in the third embodiment. According to the figure, based on the color gamut ratio C between the input medium and the output medium, a γ value indicating the relationship between the color distribution of the input medium and the color distribution of the output medium can be easily calculated. That is, in the third embodiment, the relationship between the outermost color distribution of the input medium and the output medium can be set by the γ value determined based on the color gamut ratio C.

  As described above, according to the third embodiment, the γ value indicating the relationship between the outermost color distributions can be automatically set based on the size ratio C of the color gamut of the input medium and the output medium. That is, the saturation adjustment based on the γ value can be automatically set.

<Modification>
Hereinafter, modifications to the above-described first to third embodiments will be described.

  Although the example in which the number of grid points of the color matching LUT created in step S207 in FIG. Needless to say, the score can be changed.

  Although the color space used for color gamut compression has been described by taking CIELAB as an example, it goes without saying that this color space may be changed in accordance with the accuracy and purpose for which it is desired.

  Further, in the UI shown in FIG. 3, the selection method using the button and the selection method using the pull-down format are illustrated, but it goes without saying that the UI of the present invention is not limited to this example. For example, the menu format may be selected by the user or the keyword may be directly input by the user. In other words, any UI configuration that enables the setting desired by the user may be used.

  In the present invention, a color using a table for an image signal input from a first apparatus between a first apparatus (for example, a monitor) and a second apparatus (for example, a printer) having different color reproduction ranges. This is effective when image processing is performed such that the image is converted and output to the second device. It is also effective when inputting / outputting color image data between different media / devices, such as when you want to reproduce images output from a printer using glossy paper on plain paper without gloss. It goes without saying that it applies.

<Other embodiments>
Although the embodiments have been described in detail above, the present invention can take embodiments as, for example, a system, an apparatus, a method, a program, or a storage medium (recording medium). The present invention may be applied to a system composed of a single device or an apparatus composed of a single device.

  In the present invention, a software program (in the embodiment, a program corresponding to the flowchart shown in the figure) that realizes the functions of the above-described embodiment is directly or remotely supplied to the system or apparatus, and the computer of the system or apparatus Is also achieved by reading and executing the supplied program code.

  Accordingly, since the functions of the present invention are implemented by computer, the program code installed in the computer also implements the present invention. In other words, the present invention includes a computer program itself for realizing the functional processing of the present invention.

  In that case, as long as it has the function of a program, it may be in the form of object code, a program executed by an interpreter, script data supplied to the OS, or the like.

  As a recording medium for supplying the program, for example, floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, MO, CD-ROM, CD-R, CD-RW, magnetic tape, nonvolatile memory card , ROM, DVD (DVD-ROM, DVD-R).

  As another program supply method, a client computer browser is used to connect to an Internet homepage, and the computer program of the present invention itself or a compressed file including an automatic installation function is downloaded from the homepage to a recording medium such as a hard disk. Can also be supplied. It can also be realized by dividing the program code constituting the program of the present invention into a plurality of files and downloading each file from a different homepage. That is, a WWW server that allows a plurality of users to download a program file for realizing the functional processing of the present invention on a computer is also included in the present invention.

  In addition, the program of the present invention is encrypted, stored in a storage medium such as a CD-ROM, distributed to users, and key information for decryption is downloaded from a homepage via the Internet to users who have cleared predetermined conditions. It is also possible to execute the encrypted program by using the key information and install the program on a computer.

  In addition to the functions of the above-described embodiments being realized by the computer executing the read program, the OS running on the computer based on the instructions of the program is a part of the actual processing. Alternatively, the functions of the above-described embodiment can be realized by performing all of them and performing the processing.

  Furthermore, after the program read from the recording medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion board or The CPU or the like provided in the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are also realized by the processing.

It is a block diagram which shows the structure of the image processing apparatus in one Embodiment which concerns on this invention. It is a flowchart which shows the color gamut compression process in this embodiment. It is a figure which shows the example of UI with respect to the color gamut compression process of this embodiment. It is a flowchart which shows the outermost outline color storage process in this embodiment. It is a figure which shows the WP-Bk line in this embodiment. It is a flowchart which shows the outermost color compression process in this embodiment. It is a figure explaining the color gamut compression method in the outermost outline of a color gamut. It is a figure which shows the color distribution of the WP line of the outermost color. It is a figure which shows the relationship between the color distribution of an input medium, and the color distribution of an output medium. It is a flowchart which shows the color compression process in a color gamut in this embodiment. It is a figure explaining the color gamut compression method in a color gamut. It is a figure explaining the concept of the saturation in the color gamut compression in a color gamut. FIG. 10 is a diagram illustrating a UI example for adjusting the relationship between color distributions of input media and output media in the second embodiment. FIG. 10 is a diagram illustrating a method for calculating a color gamut ratio between an input medium and an output medium in the third embodiment. In the third embodiment, it is a diagram showing the relationship between the color gamut ratio and γ value of the input medium and the output medium. FIG. 6 is a diagram illustrating a difference between a monitor color gamut and a printer color gamut.

Claims (15)

Between the first apparatus and the second apparatus having different color reproduction ranges, the image signal input from the first apparatus is subjected to color conversion using a table and is output to the second apparatus. An image processing method comprising:
A color gamut compression step for performing color gamut compression corresponding to a color within the color reproduction range of the first device and a color within the color reproduction range of the second device;
A first outermost color distribution setting step for setting a color distribution of an outermost color in a color reproduction range in the first device;
A second outermost color distribution setting step for setting a color distribution of the outermost color in the color reproduction range in the second device;
Based on the color distribution of each outermost color set in the first and second outermost color distribution setting steps, the outermost color of the color reproduction range in the first device and the color reproduction in the second device. An outermost color gamut compression step for performing color gamut compression corresponding to the outermost color of the range;
A table creation step of creating the table based on a color gamut compression result obtained by the intra-gamut compression step and the outermost color gamut compression step;
An image processing method comprising:   In the second outermost color distribution setting step, the color distribution of the outermost color in the second device is the outermost color in the first device set in the first outermost color distribution setting step. 2. The image processing method according to claim 1, wherein the image processing method is set so as to exhibit a color reproducibility that is relatively similar to the color distribution. Furthermore, a target color setting step for setting a target color group to be subjected to color conversion,
A first assigning step of assigning the set target color group to a color within the color reproduction range of the first device and an outermost color of the color reproduction range;
In the first outermost color distribution setting step, the color distribution of the outermost color in the first device is set based on the target color distributed as the outermost color in the first distribution step. The image processing method according to claim 2. Further, the target color assigned as the outermost color in the first assigning step is not on the line on the line on the white-primary black color transition line of the color reproduction range in the first device. A second distribution step for distributing to out-of-line values;
4. The image according to claim 3, wherein in the first outermost color distribution setting step and the second outermost color distribution setting step, a color distribution of the outermost color is set based on the on-line value. Processing method.   5. The image processing method according to claim 4, wherein, in the outermost color compression step, the color gamut compression result of the out-of-line value is interpolated based on the color gamut compression result of the above-line value.   6. The image processing method according to claim 1, wherein a color reproduction range in the first and second devices is set on a lightness-saturation plane. And a saturation adjustment step of changing brightness and saturation in the second device based on a user instruction,
In the second outermost color distribution setting step, the color distribution of the outermost color of the color reproduction range in the second device is set based on the lightness and saturation adjusted in the adjustment step again. The image processing method according to claim 2, wherein the image processing method is an image processing method.   The image processing method according to claim 7, wherein, in the saturation adjustment step, a relationship between color distributions of outermost colors in the first device and the second device is changed. And a color gamut shape determining step for determining a size ratio of a color reproduction range in the first device and the second device,
7. The color distribution of the outermost color in the color reproduction range in the second device is set based on the size ratio in the second outermost color distribution setting step. An image processing method according to claim 1. The second device is connected between a first device and a second device having different color reproduction ranges, and color conversion using a table is performed on the image signal input from the first device, and the second device An image processing apparatus for outputting to an apparatus,
In-gamut color compression means for performing color gamut compression in which a color in the color reproduction range in the first device and a color in the color reproduction range in the second device correspond to each other;
First outermost color distribution setting means for setting a color distribution of the outermost color of the color reproduction range in the first device;
Second outermost color distribution setting means for setting the color distribution of the outermost color in the color reproduction range in the second device;
Based on the color distribution of each outermost color set by the first and second outermost color distribution setting means, the outermost color of the color reproduction range in the first device and the color reproduction in the second device Outermost color gamut compression means for performing color gamut compression corresponding to the outermost color of the range;
Table creating means for creating the table based on a color gamut compression result by the in-gamut compression means and the outermost color gamut compression means;
An image processing apparatus comprising:   The second outermost color distribution setting unit sets the color distribution of the outermost color in the second device to the color distribution of the outermost color in the first device set by the first outermost color distribution setting unit. The image processing apparatus according to claim 10, wherein the image processing apparatus is set so as to exhibit a color reproducibility that is relatively similar to a color distribution. A first device and a second device having different color reproduction ranges are connected, and color conversion using a table is performed on an image signal input from the first device, and output to the second device. An image processing system that performs color matching when
In-gamut color compression means for performing color gamut compression in which a color in the color reproduction range in the first device and a color in the color reproduction range in the second device correspond to each other;
First outermost color distribution setting means for setting a color distribution of the outermost color of the color reproduction range in the first device;
Second outermost color distribution setting means for setting the color distribution of the outermost color in the color reproduction range in the second device;
Based on the color distribution of each outermost color set by the first and second outermost color distribution setting means, the outermost color of the color reproduction range in the first device and the color reproduction in the second device Outermost color gamut compression means for performing color gamut compression corresponding to the outermost color of the range;
Table creating means for creating the table based on a color gamut compression result by the in-gamut compression means and the outermost color gamut compression means;
An image processing system comprising:   The second outermost color distribution setting unit sets the color distribution of the outermost color in the second device to the color distribution of the outermost color in the first device set by the first outermost color distribution setting unit. 13. The image processing system according to claim 12, wherein the image processing system is set so as to exhibit a color reproducibility relatively similar to the color distribution.   By controlling the information processing apparatus, the information processing apparatus is operated so that the image processing method according to any one of claims 1 to 9 is realized on the information processing apparatus. program.   15. A recording medium on which the program according to claim 14 is recorded.

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