JP2007014010A - Image color correction parameter computation system, color correction method, and color correction apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color correction parameter calculation apparatus capable of automatically calculating color correction parameters for color image instruments of which the color characteristics are different from a criteria color image instrument, without implementing re-evaluation experimentation. <P>SOLUTION: A color correcting means 11 computes a target color by applying color correction processing to a criteria side input color, a criteria side color sensing quantity computing means 13 computes color sensing quantities of the criteria side input color and a target color, and a reference side color sensing quantity computing means 15 computes a color sensing quantity of a reference side input color. A minimum color difference color searching means 16 searches for a criteria side input color with a minimum color difference from a reference side input color, out of data in a color sensing quantity storage memory 14 for input color and target color. A reference color image instrument depending device color computing means 17 computes device depending color data of a target color of a reference color image device from the sensing quantity of the target color, and a color correction parameter calculating means 8 calculates color correction parameters. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a color correction parameter calculation device, an image color correction device, a color correction parameter calculation method used therefor, and a program thereof, and more particularly to a reference color image device based on a color correction parameter adjusted on a reference color image device. When calculating color correction parameters for a reference color image device with different color characteristics, the effect of color appearance by color correction on the standard color image device and the color appearance by color correction on the reference color image device The present invention relates to a method for calculating a color correction parameter for a reference color image device so that the effect of the above is the same.

With the development of color image equipment, high image quality technology for color images has become an important factor. In particular, color is sensitive, and colors reproduced by color image equipment have a great influence on image quality. For example, in the case of a natural image, skin color, greenery and blue sky are said to be important objects for human beings, and image quality can be improved by reproducing these objects with preferable colors.

For example, as a technique for correcting the color of a specific object such as skin color, greenery of plants, and blue sky to a color that humans feel preferable, hue disclosed in Japanese Patent Laid-Open No. 10-198795 (Patent Document 1) Another special color correction calculation algorithm can be used. By using this method, it is possible to add color correction processing to only a specific hue without affecting other than the target hue to be corrected.

The RGB correction formula by the special color correction by hue is
(R ′, G ′, B ′) = (R, G, B) + hx · (r, g, b) (1)
It is expressed by the formula. Here, (R, G, B) is an arbitrary input RGB value in the input image, (R ′, G ′, B ′) is an RGB value after correction, and (r, g, b) is an RGB correction amount. To express.

Hx represents the distance between (Rc, Gc, Bc), which is the color that is the center of correction, and (R, G, B) of the above-mentioned arbitrary input color, and controls the intensity of correction. Parameter (spot color),
hx = {[pos (m− | Hue−h |)] / m} × s × v (2)
It is defined by the expression. Here, pos (x) is 0 when x <0, and x when x ≧ 0. In addition, m is an allowable hue angle, Hue (hue) is a correction center color (Rc, Gc, Bc), a HSV (specific hue correction method by hue), h, s, and v are arbitrary. HSV values (h, s, v) for input RGB values.

In order to realize preferable color reproduction, the RGB correction amount (r, g, b) in the equation (1) and the allowable hue angle m in the equation (2) according to the hue of the representative color to be corrected. It is necessary to give the optimum value to. In particular, among the two types of color correction parameters, the RGB correction amount (r, g, b), which is a color correction parameter for changing the correction target color to the target color, is important. In the method disclosed in Japanese Patent Laid-Open No. 10-198795, a person adjusts a color correction parameter while viewing an input image.

In addition to Japanese Patent Laid-Open No. 10-198795 (Patent Document 1), Japanese Patent Laid-Open No. 11-17969 (Patent Document 2) and Japanese Patent Laid-Open No. 6-133329 (Patent Document) can be used as color correction methods for target regions in an image. Document 3), Japanese Patent Application Laid-Open No. 6-121159, etc. (Patent Document 4) have also been proposed. The color correction parameters in these methods are adjusted until the correction target becomes a preferable color while confirming the target color in the image actually displayed (output) on the color image device. That is, manual color correction is assumed.

Now, if there are a large number of input color images, it takes a lot of labor and time to process them. Further, since the adjustment is performed manually, the quality of the image obtained varies depending on the skill level of the operator. In order to solve this problem, an automated process that does not require human intervention is required.

A method for automatically correcting the color of a specific target region to a desired color has also been proposed. For example, it is described in “Automatic Color Correction Method for Realizing Preferred Color Reproduction” (Masato Tsukada, Chisato Funayama, Joji Tajima, Color Forum Japan 2000 Proceedings, pp. 9-12, 2000.1.15: Non-Patent Document 1) There are methods that have been used.

Specifically, this method automatically extracts representative colors in the correction target area, assigns optimal color correction parameters according to the hue, brightness, and saturation of the extracted representative colors, and performs color correction processing. And a method to do this has been proposed.

Hereinafter, a method for calculating the optimum color correction parameter for the representative color disclosed in Japanese Patent Laid-Open No. 11-267937 (Patent Document 5) will be described. In the method described in Japanese Patent Laid-Open No. 11-267937 (Patent Document 5), for example, when the color correction method disclosed in Japanese Patent Laid-Open No. 10-198795 (Patent Document 6) is used, first, a large amount of learning is used. An image set is prepared, a representative color is selected for a correction target area in each image, and two types of color corrections of RGB correction amount (r, g, b) and allowable hue angle m in equation (1) are performed. The parameter is obtained by subjective evaluation, and a combination of the representative color and the color correction parameter is obtained.

Then, a hue distribution range that the correction target can take is determined from the hues of the representative colors, and the hue distribution range is created by dividing the hue distribution range at a certain interval. The color correction parameter assigned to each hue division area is obtained by calculating a representative color existing in the hue division area from the hue, obtaining a color correction parameter corresponding to the representative color, and statistically processing the color correction parameter. FIG. 10 shows a state in which color correction parameters are assigned to hue division regions obtained by dividing the hue distribution range that can be taken by the correction target.

The advantage of the method described in Japanese Patent Application Laid-Open No. 11-267937 is that the effect of color correction actually adjusted by a human is automatically and automatically applied to the color of an object important to humans such as skin color, green of plants, and blue sky. It can be effectively reflected.
JP-A-10-198795 Japanese Patent Laid-Open No. 11-17969 JP-A-6-133329 JP-A-6-121159 JP-A-11-267937 JP-A-10-198795 “Automatic Color Correction Method for Realizing Preferred Color Reproduction” (Masato Tsukada, Chisato Funayama, Joji Tajima, Color Forum Japan 2000 Proceedings, pp. 9-12, 2000.11.15

The color correction parameters in the above-described conventional color correction method are generally obtained by setting a calibrated reference color image device and performing statistical processing or the like from the result of a subjective evaluation experiment using the reference color image device. It is. In other words, since the color correction parameter depends on the color characteristics of the color image device, the above method can be applied as it is to a color image device having a color characteristic such as white different from that of the reference color image device. It is not guaranteed that the effect of color correction will be obtained.

The automatic color correction method for automatically correcting the color of a specific target area is an effective method for color correction of a specific target area in a natural image with respect to a reference color image device. Is not intended to calculate color correction parameters suitable for color image devices having different color characteristics.

The methods disclosed in JP-A-10-198795, JP-A-11-17969, JP-A-6-133329, and JP-A-6-121159, which are conventional color correction methods, are also described above. There are similar problems.

It is necessary to obtain a new color correction parameter in order to obtain the same color correction effect on the reference color image device every time the color characteristics of the color image device change. At present, there is no method for calculating a color correction parameter for a new color image device based on the color correction parameter adjusted for the reference color image device. It is necessary to conduct a subjective evaluation experiment to obtain correction parameters. This subjective evaluation experiment has a big problem that it takes a lot of labor and time.

Color correction parameters for obtaining the same effect as the color correction obtained on the standard color image device on the color image device having different color characteristics from the standard color image device, without using subjective evaluation experiments. A method of calculating well is desired.

Therefore, the object of the present invention is to solve the above-mentioned problems and automatically calculate color correction parameters for a reference color image device having a color characteristic different from that of a standard color image device without performing a re-evaluation experiment. An object of the present invention is to provide a color correction parameter calculation device, an image color correction device, a color correction parameter calculation method used therefor, and a program thereof.

A color correction parameter calculation apparatus according to the present invention calculates a color correction parameter for a reference color image device having a color characteristic different from that of the reference color image device based on a color correction parameter set for the reference color image device. A calculation device, a means for calculating a target color after color correction from an input color in the reference color image device given in advance and a color correction parameter for each color of the input color, the calculated target color and the reference Means for calculating a color perception amount of each input color in the color image device and a color perception amount of the input color in the reference color image device, and a color difference between the input color in the reference color image device based on the calculation result is minimized A minimum color difference color search means, and the reference color corresponding to the minimum color difference color searched by the minimum color difference color search means. Means for obtaining a target color in the reference color image device based on a color perception amount of the target color in the image device, and a color in the reference color image device based on the obtained target color and an input color in the reference color image device Means for calculating a correction parameter.

An image color correction apparatus according to the present invention calculates a color correction parameter for calculating a color correction parameter of a reference color image device having a color characteristic different from that of the reference color image device based on a color correction parameter set in the reference color image device. An image color correction apparatus for correcting a color of a color image of the reference color image device, the color correction from an input color and a color correction parameter for each color of the input color given in advance in the reference color image device Means for calculating a later target color, means for calculating the calculated target color and the color perception amount of each input color in the reference color image device, and the color perception amount of the input color in the reference color image device; Means for searching for a minimum color difference color having a minimum color difference from the input color in the reference color image device based on the calculation result; and Means for obtaining a target color in the reference color image device based on a color perception amount of the target color in the standard color image device corresponding to the color difference minimum color searched by the small color search means; and the obtained target color and the The color correction parameter calculating device includes means for calculating a color correction parameter in the reference color image device based on an input color in the reference color image device.

The color correction parameter calculation method according to the present invention is a color correction parameter for calculating a color correction parameter of a reference color image device having a color characteristic different from that of the reference color image device based on a color correction parameter set in the reference color image device. A calculation method, the step of calculating a target color after color correction from an input color in the reference color image device given in advance and a color correction parameter for each color of the input color, and the calculated target color and the reference A step of calculating a color perception amount of each input color in the color image device; a step of calculating a color perception amount of the input color in the reference color image device; and a step in the reference color image device from the input color in the reference color image device. A step of searching for a minimum color difference color having a minimum color difference from the input color, and the searched color Setting a color perception amount of the target color in the reference color image device corresponding to the minimum color as a color perception amount of the target color corresponding to the input color in the reference color image device; and color perception of the set target color Calculating a target color in the reference color image device by converting the quantity into a device-dependent color from the reference color image device; and a color in the reference color image device from an input color and a target color in the reference color image device Calculating a correction parameter.

The color correction parameter calculation method program according to the present invention calculates a color correction parameter for a reference color image device having color characteristics different from those of the reference color image device, based on the color correction parameter set for the reference color image device. A correction parameter calculation method program for calculating a target color after color correction from an input color and a color correction parameter for each color of the input color given to the computer in advance in the reference color image device, and the calculation Processing for calculating the perceived color of each of the target color and the input color in the reference color image device, processing for calculating the color perception amount of the input color in the reference color image device, and input color in the reference color image device The minimum color difference color with the minimum color difference from the input color in the reference color image device is searched from And a process of setting a color perception amount of the target color in the reference color image device corresponding to the searched color difference minimum color as a color perception amount of the target color corresponding to the input color in the reference color image device, A process for calculating a target color in the reference color image device by converting the set color perception amount of the target color into a device-dependent color to the reference color image device; and an input color and a target color in the reference color image device; To the process of calculating the color correction parameter in the reference color image device.

That is, the color correction parameter calculation apparatus according to the present invention calculates a color correction parameter for a reference color image device having a color characteristic different from that of the reference color image device based on the color correction parameter set in the reference color image device. In the parameter calculation device, a plurality of color correction parameters are given in advance for each of the input color in the reference color image device and the input color in the reference color image device. From the input color and the color correction parameter in the reference color image device, Color correction means for calculating a target color after color correction, an input color / target color storage memory for storing an input color and a target color in the standard color image device, and a reference color image from the input color and the target color in the standard color image device Color perception amount calculation means for calculating the color perception amount of the input color in the device, and a reference color Color perception amount storage memory for storing color perception amount of input color and target color in image device, and minimum color difference color of input color in reference color image device from input color in standard color image device stored in color perception amount storage memory The color difference minimum color search means for finding the color difference and the color perception amount of the target color corresponding to the minimum color difference color are set as the color perception amount of the target color corresponding to the input color in the reference color image device, and the device dependent color of the reference color image device The color correction parameter in the reference color image device is calculated from the reference color image device dependent device color calculation means for obtaining the target color in the reference color image device by converting the input color in the reference color image device, And a color correction parameter calculation means for calculating.

Further, another color correction parameter calculation apparatus of the present invention calculates a color correction parameter of a reference color image device having a color characteristic different from that of the standard color image device, based on the color correction parameter set in the standard color image device. In the color correction parameter calculation apparatus, a plurality of color correction parameters are given in advance for each of the input color in the reference color image device and the input color in the reference color image device, and the input color and the color correction parameter in the reference color image device The color correction means for calculating the target color after color correction from the above, the reference side color perception amount calculation means for calculating the input color and the color perception amount of the target color in the reference color image equipment, and the input color in the reference color image equipment Corresponding color calculation means for calculating the corresponding color in the reference color image device, and a color perception meter for calculating the color perception amount of the corresponding color And a color difference minimum color search means for searching for a minimum color difference color of the corresponding color from input colors in the reference color image device, and a target color corresponding to the minimum color difference color is set as a target color corresponding to the corresponding color. A reference-side device color calculation means for obtaining a target color in the reference color image device by converting a target color corresponding to the reference color into a device-dependent color in the reference color image device, and an input color in the reference color image device and a target color in the reference color image device And color correction parameter calculation means for calculating color correction parameters in the reference color image device.

Furthermore, another color correction parameter calculation apparatus according to the present invention calculates a color correction parameter of a reference color image device having a color characteristic different from that of the standard color image device based on the color correction parameter set in the standard color image device. In the color correction parameter calculation apparatus, a plurality of color correction parameters are given in advance for each of the input color in the reference color image device and the input color in the reference color image device, and the input color and the color correction parameter in the reference color image device Correction means for calculating the target color after color correction from the above, a corresponding color calculation means for calculating the input color in the standard color image device and the corresponding color in the reference color image device of the target color, and the input color in the standard color image device -Side color knowledge to calculate color perception amount of corresponding color in reference color image equipment of target and target colors An amount calculation means; a color perception amount calculation means for calculating a color perception amount of an input color in a reference color image device; and an input color in a reference color image device from a corresponding color in a reference color image device in a reference color image device. The color difference minimum color search means for searching for the minimum color difference color, the corresponding color in the reference color image device of the target color corresponding to the minimum color difference color is set as the target color corresponding to the input color in the reference color image device, and the reference color image device Reference-side device color calculation means for obtaining a target color in the reference color image device by calculating a device-dependent color on the reference color image device from the target color corresponding to the input color, and the input color and the reference color image in the reference color image device The color correction parameters for the reference color image device are determined from the target color in the device. It is characterized in that it comprises a color correction parameter calculating means for calculation.

The image color correction apparatus of the present invention is an image color correction apparatus for correcting the color of a color image, to which a reference color image apparatus is connected, and color characteristics of the reference color image apparatus and reference-side observation environment data are given. A color information storage memory on the reference side for storing color information, observation environment information, input color, and color correction parameters of the reference color image device, one of the color correction parameter calculation devices, and a color correction parameter A color correction parameter set for the reference color image device output by the calculation device and an image color correction unit that performs color correction on the input image, an output image storage memory that stores an output image of the image color correction unit, and an output image And an image display means for displaying or outputting to the reference color image device.

The color correction parameter calculation method of the present invention is a method for calculating a color correction parameter of a reference color image device having a color characteristic different from that of the reference color image device based on the color correction parameter set in the reference color image device. A plurality of color correction parameters are given in advance for each color of the input color in the color image device and the input color in the reference color image device, and the target color after color correction from the input color and color correction parameter in the reference color image device Calculating a color perception amount of the input color and the target color in the standard color image device, calculating a color perception amount of the input color in the reference color image device, and an input color in the standard color image device To find the minimum color difference color of the input color in the reference color image device from Setting the color perception amount of the corresponding target color as the color perception amount of the target color corresponding to the input color in the reference color image device, and the reference color from the color perception amount of the target color corresponding to the input color in the reference color image device The color correction parameters in the reference color image device are calculated from the steps of calculating the target color in the reference color image device by converting the device-dependent color into the image device, and the input color in the reference color image device and the target color in the reference color image device. And a calculating step.

According to another color correction parameter calculation method of the present invention, a color correction parameter of a reference color image device having a color characteristic different from that of the standard color image device is calculated based on the color correction parameter set in the standard color image device. In the method, a plurality of color correction parameters are given in advance for each of the input color in the reference color image device and the input color in the reference color image device, and color correction is performed from the input color and the color correction parameter in the reference color image device. Calculating a later target color; calculating an input color in the reference color image device and a color perception amount of the target color; calculating a corresponding color in the reference color image device of the input color in the reference color image device; Calculating the color perception amount of the corresponding color and the input color in the reference color image device The step of searching for the minimum color difference of the corresponding color, the step of setting the target color corresponding to the minimum color difference color as the target color corresponding to the corresponding color, and the target color corresponding to the corresponding color as the device-dependent color in the reference color image device Converting and calculating a target color in the reference color image device, and calculating a color correction parameter in the reference color image device from the input color in the reference color image device and the target color in the reference color image device. It is a feature.

Further, according to another color correction parameter calculation method of the present invention, a color correction parameter of a reference color image device having a color characteristic different from that of the standard color image device is calculated based on the color correction parameter set in the standard color image device. In the method, a plurality of color correction parameters are given in advance for each of the input color in the reference color image device and the input color in the reference color image device, and color correction is performed from the input color and the color correction parameter in the reference color image device. A step of calculating a later target color, a step of calculating a corresponding color in the reference color image device of the input color and the target color in the standard color image device, and a step in the reference color image device of the input color and the target color in the standard color image device Calculating the color perception amount of the corresponding color; and Calculating a color perception amount of a force color, searching a minimum color difference color of an input color in a reference color image device from a corresponding color in a reference color image device of an input color in a standard color image device, and corresponding to a minimum color difference color Setting a target color corresponding to the reference color image device as a target color corresponding to the input color in the reference color image device, and a device on the reference color image device from the target color corresponding to the input color in the reference color image device Calculating a dependent color and calculating a target color in the reference color image device; and calculating a color correction parameter in the reference color image device from the input color in the reference color image device and the target color in the reference color image device. It is characterized by including.

By configuring as described above, a reference color image having color characteristics different from that of the standard color image device based on the color correction parameter adjusted for the standard color image device without performing a re-evaluation experiment. Color correction parameters for equipment can be automatically calculated.

In addition, re-evaluation experiments can be omitted when obtaining color correction parameters for reference color image devices that have different color characteristics from the standard color image device, based on the color correction parameters adjusted for the standard color image device. Therefore, the time and labor for obtaining the color correction parameter for the reference color image device can be reduced.
Furthermore, based on the color correction parameters adjusted for the standard color image device, the color correction parameters calculated for the reference color image device having different color characteristics from the standard color image device can be used for reference. The same color correction effect as that of the reference color image device can be obtained.

As described above, according to the present invention, the color correction parameter for calculating the color correction parameter of the reference color image device having different color characteristics from that of the reference color image device based on the color correction parameter set in the reference color image device. In the calculation device, the target color after color correction is calculated from the input color in the reference color image device given in advance and the color correction parameter for each color of the input color, and each of the calculated target color and the input color in the reference color image device The color perception amount of the input color in the reference color image device and the color perception amount of the input color in the reference color image device are calculated, and the minimum color difference with the minimum color difference from the input color in the reference color image device is searched based on this calculation result. Target color in reference color image equipment based on color perception amount of target color in standard color image equipment corresponding to minimum color difference And calculating the color correction parameter in the reference color image device based on the obtained target color and the input color in the reference color image device. There is an effect that it is possible to automatically calculate color correction parameters for a reference color image device having different characteristics.

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a color correction parameter calculation apparatus according to an embodiment of the present invention. In FIG. 1, a color correction parameter calculation apparatus 1 includes a color characteristic 2 of a standard color image apparatus, a color characteristic 3 of a reference color image apparatus, a color correction parameter set 4, an input color set 5, an observation environment data 6 on the reference side, and a reference side. Each of the observation environment data 7 is required to be input.

The color correction parameter calculation apparatus 1 includes a color correction unit 11, an input color / target color storage memory 12, a reference side color perception amount calculation unit 13, an input color / target color perception amount storage memory 14, and a reference side The color perception amount calculation means 15, the color difference minimum color search means 16, the reference color image device dependent device color calculation means 17, and the color correction parameter calculation means 18 are configured. Each of the above means is stored in the recording medium 101. The program is executed to output the color correction parameter set 8 for the reference color image device.

The color correction means 11 receives as input an input color set 5 composed of a plurality of color data before color correction and a color correction parameter set 4 composed of color correction parameters corresponding to each input color. The target color is calculated by performing color correction processing, and the input color and the target color are combined and recorded in the input color / target color storage memory 12 sequentially.

The reference color perception amount calculation means 13 receives as input the color characteristics 2 of the reference color image device, the reference observation environment data 6, and the input color and target color stored in the input color / target color storage memory 12. The color perception amounts of all input colors and target colors are calculated and recorded in the color perception amount storage memory 14 of the input colors and target colors.

The reference side color perception amount calculation means 15 receives the color characteristic 3 of the reference color image device, the input color set 5, and the observation environment data 7 on the reference side, and calculates the color perception amount of the input color on the reference side.

The color difference minimum color search means 16 uses the input side / target color color perception amount storage memory 14 for the reference side input color calculated by the reference side color perception amount calculation means 15 and having the minimum color difference from the reference side input color. The corresponding input color and its target color are obtained by searching from the data stored in.

The reference color image device dependent device color calculation unit 17 calculates device dependent color data of the target color in the reference color image device from the perceived amount of the target color obtained by the minimum color difference color search unit 16, and the color correction parameter calculation unit 18 Color correction parameters are calculated from the input color data and the device-dependent color data of the target color.

2 is a flowchart showing the operation of the color correction parameter calculation apparatus 1 according to an embodiment of the present invention, and FIG. 3 is a diagram showing a configuration example of the input color / target color storage memory 12 of FIG. FIG. 2 is a diagram illustrating a configuration example of a color perception amount storage memory 14 of the input color / target color in FIG. 1. A specific operation of the color correction parameter calculation apparatus 1 according to an embodiment of the present invention will be described with reference to FIGS. 2 is realized by executing the program stored in the recording medium 101 by each of the above means.

Hereinafter, a reference color image device (not shown) having a color characteristic different from that of the standard color image device (not shown) is required to reproduce the same effect as the color correction in the standard color image device. A specific method for calculating the color correction parameter for the reference color image apparatus will be described. In order to make the description easier to understand, the color correction processing targeted by the color correction parameter calculation apparatus 1 is the color correction method and color described in Japanese Patent Laid-Open No. 10-198795 described in the related art. A case where a correction parameter is used and a monitor is used for the color image apparatus will be described.

In addition, in order to calculate a color correction parameter set of a reference monitor (hereinafter referred to as a reference monitor) (not shown), the color of a reference monitor (hereinafter referred to as a reference monitor) (not shown) and the reference monitor The characteristics, the observation environment data on the standard monitor side, the observation environment data on the reference monitor side, the input color set extracted from the correction target area, and the color correction parameter set corresponding to the input color set are respectively input to the color correction parameter calculation apparatus 1 It is assumed that it is obtained as data. In this case, the color correction parameter calculation apparatus 1 shows an embodiment in which a color appearance model is used.

The color correction parameter calculation device 1 calculates the target color after color correction using the input color and its color correction parameter in the reference monitor (step S1 in FIG. 2), and calculates the color perception amount of the input color and the target color in the reference monitor. Calculation is performed using the color appearance model (step S2 in FIG. 2).

Similarly to the above, the color correction parameter calculation apparatus 1 calculates the color perception amount of the input color on the reference monitor (step S3 in FIG. 2), and the color perception amount of the input color on the reference monitor from the input color set on the standard monitor. An input color that is closest to, i.e., having the smallest color difference is found (step S4 in FIG. 2).

Thereafter, the color correction parameter calculation apparatus 1 sets the color perception amount of the target color corresponding to the input color obtained in step S4 as the color perception amount of the target color corresponding to the input color of the reference monitor (step S5 in FIG. 2). . Further, the color correction parameter calculation apparatus 1 obtains the target color on the reference monitor by converting the color perception amount of the target color on the reference monitor obtained in step S5 into the device-dependent color on the reference monitor (step S6 in FIG. 2). Further, the color correction parameter calculation device 1 calculates a color correction parameter in the reference monitor from the input color and the target color in the reference monitor (step S7 in FIG. 2).

The color correction parameters to be obtained for the reference monitor are the RGB correction amounts (r, g, b) in the equation (1) described in the prior art and the allowable hue angle m in the equation (2). Here, the RGB correction amount (r, g, b) is an important parameter that greatly influences the result of color correction, but the allowable hue angle m is corrected uniformly only in the correction target region due to the nature of the parameter. The color correction parameters are set so as to be rough, and are not very severe color correction parameters. In this case, it has been empirically confirmed that even if the same allowable hue angle m set on the standard monitor is used on the reference monitor, there is no adverse effect. Therefore, for the allowable hue angle m, the value set for the standard monitor can be used for the reference monitor.

Further, the input color (R _c , G _c , B _c ) extracted from the correction target area in the input color set 5 and the RGB correction amount (r, g, b) corresponding to each input color in the color correction parameter set 4 Is obtained in advance from a subjective evaluation experiment or the like. Specifically, the input color (R _c , G _c , B _c ) is arbitrarily extracted from the correction target area in the natural image, and after adjusting the allowable hue angle m, the RGB correction amount (r, g, b) ).

First, the color correction unit 11 corresponding to the processing in step S1 will be described. The target colors (R _t , G _t , B _t ) after the correction of the input colors (R _c , G _c , B _c ) by the equations (1) and (2) of the color correction process in the color correcting unit 11 are
( _Rt , _Gt , _Bt )
= (R _c , G _c , B _c )
+ {[Pos (m− | Hue−h |)] / m} × s × v
・ (R, g, b) (3)
It is calculated from the formula. Here, Hue is the hue value H when the input color (R _c , G _c , B _c ) is converted to HSV, and h is the hue value of the input value (R _c , G _c , B _c ). Therefore, Hue = h, and equation (3) becomes
( _Rt , _Gt , _Bt )
= (R _c , G _c , B _c ) + s′v ′ (r, g, b) (4)
It becomes.

The color (R _c , G _c , B _c ) on the reference monitor is converted into the desired target color (R _t , G _t , B _t ) by the RGB correction amount (r, g, b) in the equation (4). The input color / target color is stored in the storage memory 12. Here, an example of the configuration of the input color / target color storage memory 12 is shown in FIG. 3. However, the present invention is not limited to this as long as the target color can be read from the input color.

Now, consider that a reference monitor having color characteristics (white and RGB phosphor chromaticities) different from those of the standard monitor obtains the same effect as the color correction on the standard monitor. As described above, since (Rt, Gt, Bt) and (r, g, b) in the equation (4) are all device-dependent, it is meaningless to apply the values as they are to the reference monitor (same It does not become a color).

Thus, reproducing the same color between color image devices having different color characteristics can be directly applied to the problem of color management. On the reference monitor, (R ₁ , G ₁ , B ₁ ) that are the center colors (input colors) to be corrected and (tR ₁ , tG ₁ , tB ₁ ) of the target colors are obtained. The color appearance model can be applied to calculate an unknown color correction parameter so that the same correction result can be obtained on the reference monitor. Here, as a color appearance model or a chromatic adaptation model, CIELab, CIECAM97s2, etc. proposed by CIE (International Lighting Commission) can be used.

First, it is assumed that the input color set 5 before correction on the reference monitor as many as the color distribution space of the correction target region is provided and the color correction parameter set 4 corresponding to the input color set are given. By performing color correction processing using the input color set 5 and the color correction parameter set 4 in the reference monitor, a corrected output color set is calculated.

Now, arbitrary input RGB values (R ₂ , G ₂ , B ₂ ) existing in the color distribution area of the correction target area are displayed on the reference monitor. At this time, since the color characteristics of the standard monitor and the reference monitor are different, even if the RGB values are the same, the color displayed on the reference monitor is apparently different from the color on the standard monitor. Here, arbitrary input RGB values (R ₂ , G ₂ , B ₂ ) existing in the color distribution area of the correction target area displayed on the reference monitor use the input color obtained in advance for the reference monitor as it is. May be. This is because the input color previously obtained for the standard monitor is arbitrarily extracted from the correction target area in the natural image, and even if this image is displayed on the reference monitor, the input color is corrected. This is because there is no change in the color on the target area.

Calculate target colors (tR ₂ , tG ₂ , tB ₂ ) on the reference monitor corresponding to arbitrary input colors (R ₂ , G ₂ , B ₂ ) existing in the color distribution area of the correction target area on the reference monitor As an example of calculating the RGB correction amount from the set of the input color and the target color, a case where the CIELab model is used as the color appearance model will be described. The white XYZ of the standard monitor is ( _Xw1 , _Yw1 , _Zw1 ), the white XYZ of the reference monitor is ( _Xw2 , _Yw2 , _Zw2 ), and the RGB → XYZ conversion matrix RX1 of the standard monitor and the reference It is assumed that the RGB → XYZ conversion matrix RX2 of the monitor and the inverse XYZ → RGB conversion matrix XR2 are calculated in advance.

First, the color perception amount of the input color and target color stored in the input color / target color storage memory 12 is calculated by the reference side color perception amount calculation means 13. The perceived amount Lab is calculated for the i-th input color (R _1i , G _1i , B _1i ) and the target color (tR _1i , tG _1i , tB _1i ) after color correction in the reference monitor. In Lab calculation, white (X _w 1, Y _w1 , Z _w1 ) is designated.

The color perception amount (L _1i , a _1i , b _1i ) of the i-th input color (R _1i , G _1i , B _1i ) in the reference monitor is

……（５）

...... (5)

……（６）
という式から求められる。ここで、関数Ｆ（）は、ＸＹＺ→Ｌａｂ変換を表す関数である。

...... (6)
It is calculated from the formula. Here, the function F () is a function representing XYZ → Lab conversion.

The color perception amount (tL _1i , ta _1i , tb _1i ) of the target color corresponding to the i-th input color is

……（７）

...... (7)

……（８）
という式から求められる。

...... (8)
It is calculated from the formula.

The color perception amount of the input color and the target color calculated by the reference side color perception amount calculation means 13 is recorded in the input color / target color perception amount storage memory 14. FIG. 4 shows a configuration example of the color perception amount storage memory 14 for the input color and the target color. However, as long as the color perception amount of the input color and the color perception amount of the target color can be read out as a set, this is the limit. is not.

The reference side color perception amount calculation means 15 calculates the color perception amount (L ₂ , a ₂ , b ₂ ) of the input color (R ₂ , G ₂ , B ₂ ) in the reference monitor.

……（９）

...... (9)

……（１０）
という式から計算する。

...... (10)
Calculate from the formula.

The color difference minimum color search means 16 calculates the color difference from the color perception amount (L ₂ , a ₂ , b ₂ ) from the input color set of the reference monitor recorded in the color perception amount storage memory 14 of the input color / target color. Select the color that is the smallest (the difference in perceptual amount is the smallest). The target color perception amount (tL ₁ , ta ₁ , tb ₁ ) corresponding to the input color of the reference monitor having the smallest color difference from the color perception amount (L ₂ , a ₂ , b ₂ ) is input to the reference monitor. The perceived amount (tL, ta, tb) of the target color corresponding to (R2, G2, B2). The perceived amount (tL, ta, tb) of this target color is
(TL, ta, tb) = (tL ₁ , ta ₁ , tb ₁ ) (11)
It is.

In the reference color image device dependent device color calculation means 17, the RGB values (tR ₂ , tG ₂ , tB ₂ ) on the reference monitor corresponding to the perceived amount (tL, ta, tb) of the target color are calculated.

……（１２）

(12)

……（１３）
という式から計算する。ここで、白色は（Ｘw₂，Ｙw₂，Ｚw₂）を指定する。また、逆関数Ｆ-1（）はＬａｂ→ＸＹＺ変換を表す関数である。

(13)
Calculate from the formula. Here, for white, (Xw ₂ , Yw ₂ , Zw ₂ ) is designated. The inverse function F-1 () is a function representing Lab → XYZ conversion.

In the color correction parameter calculation means 18, the reference monitor's input color (R ₂ , G ₂ , B ₂ ) and the corresponding color-corrected target color (tR ₂ , tG ₂ , tB ₂ ) are used. The RGB correction amount (r ′, g ′, b ′) in the device-dependent RGB space is
(R ′, g ′, b ′)
= ((TR ₂ , tG ₂ , tB ₂ ) − (R ₂ , G ₂ , B ₂ )) / s ₂ / v ₂ (14)
Calculate from the formula. Here, s ₂ and v ₂ are the s value and v value when the input color (R ₂ , G ₂ , B ₂ ) in the reference monitor is RGB → HSV converted.

For all input colors, the color correction parameters in the reference color image device are calculated and output as a color correction parameter set 8 for the reference color image device. In addition to CIELab, a model for predicting the same color on the reference monitor, the RGB phosphor, and the reference monitor having different white chromaticities may use the color appearance models of CIECAM97s2, RLab, Nayatani, and Llab. it can. Since these models can calculate the amount of human color perception, the color correction parameters in the reference monitor can be calculated in the same manner as CIELab.

FIG. 5 is a block diagram showing the configuration of a color correction parameter calculation apparatus according to another embodiment of the present invention. In FIG. 5, the basic configuration of a color correction parameter calculation apparatus 9 according to another embodiment of the present invention is the same as that of the color correction parameter calculation apparatus 1 according to the embodiment of the present invention shown in FIG. Are denoted by the same reference numerals. The operation of the same component is the same as that of the embodiment of the present invention. However, the color correction parameter calculation device 9 according to another embodiment of the present invention uses a chromatic adaptation model instead of the color appearance model used in the color correction parameter calculation device 1.

The color correction parameter calculation device 9 includes color characteristics 2 of the standard color image device, color characteristics 3 of the reference color image device, color correction parameter set 4, input color set 5, reference side observation environment data 6, and reference side observation environment data. 7 Each input is required.

The color correction parameter calculation device 9 includes a reference side color information integration unit 19, a reference side color information integration unit 20, a color correction unit 11, an input color / target color storage memory 12, and a reference side color perception amount calculation unit 13. Input color / target color color perception amount storage memory 14, corresponding color calculation means 21, color difference minimum color search means 16, color perception amount calculation means 22, reference-side device color calculation means 23, color correction The parameter calculation means 18 is configured to execute the program stored in the recording medium 102 and output the color correction parameter set 8 for the reference color image device.

FIG. 6 is a flowchart showing the operation of the color correction parameter calculation apparatus 9 according to another embodiment of the present invention. The operation of the color correction parameter calculation device 9 using the chromatic adaptation model will be described with reference to FIGS. Note that the processing shown in FIG. 6 is realized by executing the program stored in the recording medium 102 by each of the above-described means.

The color correction parameter calculation device 9 calculates the target color after color correction using the input color and its color correction parameter in the reference monitor (step S11 in FIG. 6), and calculates the color perception amount of the input color and target color in the reference monitor. Calculation is performed using the appearance model (step S12 in FIG. 6).

The color correction parameter calculation device 9 calculates the corresponding color of the reference color on the reference monitor on the reference monitor using the chromatic adaptation model (step S13 in FIG. 6), and calculates the color perception amount of the calculated corresponding color as a color appearance model. This is used for calculation (step S14 in FIG. 6).

Thereafter, the color correction parameter calculation device 9 finds an input color having the smallest color difference from the corresponding color from the input color set on the reference monitor (step S15 in FIG. 6), and the color difference obtained in step S15 is the smallest. The target color corresponding to the input color is set as the target color corresponding to the corresponding color (step S16 in FIG. 6).

The color correction parameter calculation device 9 calculates a device-dependent color on the reference monitor from the target color obtained in step S16 to obtain a target color on the reference monitor (step S17 in FIG. 6). Color correction parameters in the reference monitor are calculated from the input color in the reference monitor and the target color obtained in step S17 (step S18 in FIG. 6).

First, the reference side color information integration means 19 inputs the color characteristic 2 of the reference color image device and the observation environment data 6 on the reference side, and integrates the respective information. The reference-side color information integration unit 20 inputs the color characteristic 3 of the reference color image device and the reference-side observation environment data 7 and integrates the respective information.

The color correction means 11 inputs an input color set 5 composed of a plurality of color data before color correction and a color correction parameter set 4 composed of color correction parameters corresponding to each input color, and for all input colors. Then, color correction processing is performed to calculate the target color, and the input color and the target color are combined and recorded in the input color / target color storage memory 12 sequentially.

The reference-side color perception amount calculation means 13 inputs the color characteristics 2 of the reference color image device and the reference-side observation environment data 6 and the input color and target color stored in the input color / target color storage memory 12. The color perception amount on the reference side of all input colors and target colors is calculated and recorded in the color perception amount storage memory 14 of the input color / target color.

The corresponding color calculation means 21 inputs the input color set 5, the color characteristics 2 of the standard color image device and the reference side observation environment data 6, and the color characteristics 3 of the reference color image device and the reference side observation environment data 7. The corresponding color on the reference side of the input color of the color image device on the reference side is calculated. The color perception amount calculation means 22 inputs the color characteristics 2 of the reference color image device and the observation environment data 6 on the reference side, and calculates the color perception amount of the corresponding color calculated by the corresponding color calculation means 21.

The color difference minimum color searching means 16 searches the input color on the reference side having the smallest color difference from the corresponding color from the data stored in the color perception amount storage memory 14 of the input color / target color, and the corresponding input color. And its target color.

The reference-side device color calculation means 23 inputs the color characteristic 2 of the standard color image device and the observation environment data 6 on the standard side, the color property 3 of the reference color image device, and the observation environment data 7 on the reference side, and the minimum color difference color The target color obtained by the search means 16 is converted into device-dependent color data of the target color in the reference color image device. The color correction parameter calculation means 18 calculates a color correction parameter from the input color and the device-dependent color data of the target color.

In the color correction parameter calculation apparatus 9, the operations of the color correction means 11 corresponding to the process of step S11 and the reference side color perception amount calculation means 13 corresponding to the process of step S12 are the same as those of the color correction parameter calculation apparatus 1 described above. Therefore, the explanation is omitted.

The reference side color information integration means 19 supplies a signal obtained by combining the color characteristic 2 of the reference color image device and the observation environment data 6 on the reference side, and the reference side color information integration means 20 provides the color characteristic 3 of the reference color image device. A signal obtained by combining the observation environment data 7 on the reference side is supplied. Here, in the present embodiment, in order to make the configuration of the color correction parameter calculation device 9 simpler and easier to understand, only the reference side color information integration unit 19 and the reference side color information integration unit 20 are incorporated. There is no need for the two means.

Next, the operation of the corresponding color calculation unit 21 corresponding to the process of step S13 will be described. First, the corresponding colors (X ′ ₂ , Y ′ ₂ , Z ′ ₂ ) on the reference monitor of the input colors (R ₂ , G ₂ , B ₂ ) on the reference monitor are

……（１５）

...... (15)

……（１６）
という式に基づいて計算する。ここで、関数ＣＡＭ（）は色順応モデルによる色変換を表す関数である。例えば、色順応モデルにｖｏｎ Ｋｒｉｅｓモデルや特開２０００−１１３１７４号公報に記載の手法を用いた場合には、変換元の白色のＸＹＺ値と変換先の白色のＸＹＺ値とを与える必要がある。この場合、（１６）式の右辺の関数ＣＡＭ内の第二引数が変換元の白色のＸＹＺ値であり、参照側色情報統合手段２０から得られ、関数ＣＡＭ内の第三引数が変換先の白色のＸＹＺ値であり、基準側色情報統合手段１９から得られる。

...... (16)
Calculate based on the following formula. Here, the function CAM () is a function representing color conversion by the chromatic adaptation model. For example, when the von Kries model or the method described in Japanese Patent Laid-Open No. 2000-113174 is used as the chromatic adaptation model, it is necessary to give the white XYZ value of the conversion source and the white XYZ value of the conversion destination. In this case, the second argument in the function CAM on the right side of equation (16) is the white XYZ value of the conversion source, obtained from the reference side color information integration means 20, and the third argument in the function CAM is the conversion destination. It is a white XYZ value and is obtained from the reference side color information integration means 19.

In the color perception amount calculation means 22, the color perception amount (L ₂ , a ₂ , b ₂ ) of the corresponding color (X ′ ₂ , Y ′ ₂ , Z ′ ₂ ) on the reference monitor obtained by the equation (16) is obtained. ,

……（１７）
という式から計算する。ここで、関数Ｆは（６）式における関数Ｆと同じである。

(17)
Calculate from the formula. Here, the function F is the same as the function F in the equation (6).

In the color difference minimum color search means 16, the color difference from (L ₂ , a ₂ , b ₂ ) calculated by the expression (17) is the minimum (the difference in the color perception amount is the minimum) from the input color set of the reference monitor. Select a color. Then, target colors (tR ₁ , tG ₁ , tB ₁ ) corresponding to the input color of the standard monitor having the smallest color difference are set as target colors for the corresponding color on the standard monitor of the input color of the reference monitor.

In the reference-side device color calculation means 23, the RGB values (tR ₂ , tG ₂ , tG ₂ , tG ₂ , tG ₂ , which are device-dependent colors on the reference monitor of the target colors (tR ₁ , tG ₁ , tB ₁ ) obtained by the color difference minimum color search means 16. tB ₂ ) is calculated.

First, target colors (tR ₁ , tG ₁ , tB ₁ ), which are device-dependent colors of the reference side device, are

……（１８）
という式で非デバイス依存色（ｔＸ₁ ，ｔＹ₁ ，ｔＺ₁ ）に変換する。

...... (18)
This is converted into non-device dependent colors (tX ₁ , tY ₁ , tZ ₁ ).

Next, the corresponding colors (tX ₂ , tY ₂ , tZ ₂ ) on the reference side corresponding to the target colors (tX ₁ , tY ₁ , tZ ₁ ) on the reference side device are

……（１９）
という式で色順応モデルを用いて計算する。

...... (19)
This is calculated using a chromatic adaptation model.

And (tX ₂ , tY ₂ , tZ ₂ ) which is a non-device dependent color,

……（２０）
という式で参照側デバイスにおけるデバイス依存色（ｔＲ₂ ，ｔＧ₂ ，ｔＢ₂ ）に変換する。この（２０）式の（ｔＲ₂ ，ｔＧ₂ ，ｔＢ₂ ）が参照モニタにおける入力色に対するターゲット色となる。

...... (20)
This is converted into device-dependent colors (tR ₂ , tG ₂ , tB ₂ ) in the reference side device. (TR ₂ , tG ₂ , tB ₂ ) in the equation (20) is the target color for the input color in the reference monitor.

Finally, in the color correction parameter calculation means 18, the color in the reference monitor for obtaining the target color (tR ₂ , tG ₂ , tB ₂ ) after color correction corresponding to the input color (R 2, G 2, B ₂ ) in the reference monitor. Correction parameter RGB correction amount (r ′, g ′, b ′)
(R ′, g ′, b ′)
_{= ((TR 2, tG 2} , tB2) - (R 2, G 2, B 2)) / s 2 / v 2 ...... (21)
Calculate with the following formula. As the chromatic adaptation model used in the color correction parameter calculation device 9, the von Kries model or the method described in Japanese Patent Laid-Open No. 2000-113174 can be used.

FIG. 7 is a block diagram showing the configuration of a color correction parameter calculation apparatus according to another embodiment of the present invention. In FIG. 7, the color correction parameter calculation device 10 uses a chromatic adaptation model, as in the other embodiments of the present invention. The color characteristic 2 of the standard color image device, the color property 3 of the reference color image device, and the color correction. Each of the parameter set 4, the input color set 5, the reference-side observation environment data 6, and the reference-side observation environment data 7 is required to be input.

The color correction parameter calculation apparatus 10 includes a reference side color information integration unit 19, a reference side color information integration unit 20, a color correction unit 11, an input color / target color storage memory 12, and a reference side color perception amount calculation unit 13. Input color / target color color perception amount storage memory 14, corresponding color calculation means 21, color difference minimum color search means 16, color perception amount calculation means 22, reference-side device color calculation means 23, color correction Each of the above-described units executes a program stored in the recording medium 103 and outputs a color correction parameter set 8 for the reference color image device.

FIG. 8 is a flowchart showing the operation of the color correction parameter calculation apparatus 10 according to another embodiment of the present invention. The operation of the color correction parameter calculation apparatus 10 according to another embodiment of the present invention will be described with reference to FIGS. Note that the processing shown in FIG. 8 is realized by executing the program stored in the recording medium 103 by each of the above means.

First, the color correction parameter calculation device 10 calculates the target color after color correction using the input color and its color correction parameter in the standard monitor (step S21 in FIG. 8), and in the reference monitor of the input color and target color in the standard monitor. The corresponding color is calculated (step S22 in FIG. 8).

The color correction parameter calculation apparatus 10 calculates the color perception amount of the input color and the target color corresponding to the reference monitor obtained in step S22 using the color appearance model (step S23 in FIG. 8), and calculates the input color of the reference monitor. A color perception amount is calculated using a color appearance model (step S24 in FIG. 8).

The color correction parameter calculation device 10 finds the color having the smallest color difference from the input color on the reference monitor from the corresponding color on the reference monitor of the input color of the standard monitor (step S25 in FIG. 8). The color correction parameter calculation apparatus 10 sets the corresponding color in the reference monitor of the target color corresponding to the input color having the smallest color difference obtained in step S25 as the target color corresponding to the input color in the reference monitor (step S26 in FIG. 8). .

The color correction parameter calculation apparatus 10 calculates a device-dependent color on the reference monitor from the target color obtained in step S26, and obtains a target color on the reference monitor (step S27 in FIG. 8). The color correction parameter calculation device 10 calculates a color correction parameter in the reference monitor from the input color in the reference monitor and the target color obtained in step S27 (step S28 in FIG. 8).

The color correction parameter calculation apparatus 10 has a configuration changed using the same means and memory as those constituting the color correction parameter calculation apparatus 9 according to another embodiment of the present invention. Therefore, the operation and role of each means are the same as those in the color correction parameter calculation device 9, and the description thereof is omitted.

FIG. 9 is a block diagram showing the configuration of an image color correction apparatus according to still another embodiment of the present invention. In FIG. 9, the image color correction device 30 receives the color characteristic 3 of the reference color image device, the reference-side observation environment data 7, and the input image 25, and a reference color image device 31 is connected thereto. The image color correction device 30 includes a reference-side color information storage memory 24, a color correction parameter calculation device 1, a color correction parameter set 8 for a reference color image device, an image color correction means 26, an output image storage memory 27, An image display means 28 is provided, and an image after color correction is displayed (output) on the reference color image device 31. Note that each device and means in the image color correction device 30 executes each program by executing a program stored in the recording medium 104.

First, the color information storage memory 24 on the reference side of the image color correction apparatus 30 is preliminarily assumed to have the color characteristics 2 of the reference color image apparatus, the observation environment data 6 on the reference side, the color correction parameter set 4, and the input. The color set 5 is stored in advance in the color information storage memory 24 on the reference side. The color characteristics 3 of the reference color image device and the viewing environment data 7 on the reference side, which are input information of the image color correction device 30, are sent to the color correction parameter calculation device 1 inside the image color correction device 30.

The color correction parameter calculation device 1 includes the color characteristics of the reference color image device, the reference side observation environment data, the color correction parameter set, and the input color set necessary for calculating the color correction parameter from the reference side color information storage memory 24. And the reference color image device color correction parameter set 8 is output.

The image color correction means 26 performs color correction processing on the input image 25 that is an input to the image color correction device 30, and stores the corrected image in the output image storage memory 27. At this time, the color correction parameter uses the color correction parameter set 8 for the reference color image device. The image display means 28 displays the image stored in the output image storage memory 27 on the reference color image device 31. In the image color correction device 30, the color correction parameter calculation device 1 may be replaced with the color correction parameter calculation device 9 or the color correction parameter calculation device 10 described above.

In this way, color correction for a reference color image device having color characteristics different from that of the standard color image device based on the color correction parameters adjusted for the standard color image device without performing a re-evaluation experiment. Parameters can be calculated automatically.

In addition, re-evaluation experiments are omitted when obtaining color correction parameters for reference color image devices having different color characteristics from the standard color image devices based on the color correction parameters adjusted for the standard color image devices. Therefore, it is possible to reduce time and labor for obtaining a color correction parameter for a reference color image device.

Furthermore, based on the color correction parameters adjusted for the standard color image device, the color correction parameters calculated for the reference color image device having different color characteristics from the standard color image device can be used for reference. Thus, the same color correction effect as that of the reference color image device can be obtained.

It is a block diagram which shows the structure of the color correction parameter calculation apparatus by one Example of this invention. It is a flowchart which shows operation | movement of the color correction parameter calculation apparatus by one Example of this invention. FIG. 2 is a diagram illustrating a configuration example of an input color / target color storage memory in FIG. 1. FIG. 2 is a diagram illustrating a configuration example of a color perception amount storage memory for input colors and target colors in FIG. 1. It is a block diagram which shows the structure of the color correction parameter calculation apparatus by the other Example of this invention. It is a flowchart which shows operation | movement of the color correction parameter calculation apparatus by other Example of this invention. It is a block diagram which shows the structure of the color correction parameter calculation apparatus by another Example of this invention. It is a flowchart which shows operation | movement of the color correction parameter calculation apparatus by another Example of this invention. It is a block diagram which shows the structure of the image color correction apparatus by another Example of this invention. It is a figure which shows the setting method of the color correction parameter by a prior art example.

Explanation of symbols

1, 9, 10 Color correction parameter calculation device 2 Color characteristic 3 of reference color image device Color characteristic 4 of reference color image device 4 Color correction parameter set 5 Input color set 6 Observation environment data 7 on the reference side Observation environment data 8 on the reference side Reference color image device color correction parameter set 11 Color correction means 12 Input color / target color storage memory 13 Reference side color perception amount calculation means 14 Input color / target color perception amount storage memory 15 Reference side color perception amount calculation means 16 color difference minimum color search means 17 reference color image device dependent device color calculation means 18 color correction parameter calculation means 19 reference side color information integration means 20 reference side color information integration means 21 corresponding color calculation means 22 color perception amount calculation means 23 reference side Device color calculation means 24 Reference side color information storage memory 25 Input image 26 Image color correction means 27 Output image storage Memory 28 Image display means 30 Image color correction device 31 Reference color image devices 101 to 104 Recording medium

Claims (4)

For a reference color image device having a color characteristic different from that of the reference color image device, the color correction parameters set in the reference color image device and the reproduction of the input color reproduced by the reference color image device and the reference color image device An image color correction parameter calculation system comprising means for calculating a color correction parameter of the reference color image device based on a difference in color perception amount with respect to a color. For a reference color image device having a color characteristic different from that of the reference color image device, the color correction parameters set in the reference color image device and the reproduction of the input color reproduced by the reference color image device and the reference color image device An image color comprising means for correcting a color image reproduced by the reference color image device using a color correction parameter of the reference color image device calculated based on a difference of a color perception amount with respect to a color Correction parameter calculation system. For a reference color image device having a color characteristic different from that of the reference color image device, the color correction parameters set in the reference color image device and the reproduction of the input color reproduced by the reference color image device and the reference color image device A color correction method for correcting a color image reproduced by the reference color image device using a color correction parameter of the reference color image device calculated based on a difference of a color perception amount with respect to a color. For a reference color image device having a color characteristic different from that of the reference color image device, the color correction parameters set in the reference color image device and the reproduction of the input color reproduced by the reference color image device and the reference color image device And a color correction unit that corrects a color image reproduced by the reference color image device using a color correction parameter of the reference color image device calculated based on a difference of a color perception amount with respect to a color. Color correction device.

Images