JP2002204368A - Creation method for color correction table, creation apparatus therefor and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a creation method for color correction table, a creation apparatus for color correction table and a record medium on which the favorite colors at each region are reflected. SOLUTION: According to the present invention that is the creation apparatus for color corrective table to perform desired color correction to input image data, color data transmitted from clients 10 is collected at each region through a creation part 24c for color correction table. Then, the creation part 24c creates the color correction table based on the collected result of the color data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to gray,
The present invention relates to a method, an apparatus, and a recording medium for sampling a memory color or the like and generating a color correction table reflecting color preference for each region.

[0002]

2. Description of the Related Art Various color correction processes are performed on digital image data. For example, color correction such as increasing contrast, correcting color tone, or correcting brightness.

[0003] These color correction processes are performed by converting the image data of each pixel based on a predetermined correspondence. That is, a color conversion table is prepared, and output data is generated with reference to the color conversion table using image data of a conversion source as input data. Thereby, gray balance adjustment and memory color correction such as skin color are performed.

[0004]

However, there are cases where the preference for memory colors such as gray and skin color differs depending on the region. For example, in the United States, there is a tendency to prefer a skin color with a stronger yellow color than in Japan. For this reason, an image output apparatus that outputs a color that is preferred in each area for each area is desired.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a method, an apparatus, and a recording medium for generating a color correction table reflecting a preference of a color in each area.

[0006]

SUMMARY OF THE INVENTION In view of the above problems, the invention according to claim 1 is a method for generating a color correction table for performing desired color correction on input image data,
It is provided with a color data collection step of collecting color data for each region, and a color correction table generation step of generating a color correction table based on the collection result in the color data collection step.

According to the method of generating a color correction table for performing desired color correction on input image data configured as described above, color data is collected for each region by the color data collection step, and color correction is performed. By the table generation process,
A color correction table is generated based on the collection result in the color data collection step.

[0008] The invention described in claim 2 is the first invention.
Wherein the color data is collected in the color data collecting step via the Internet.

Further, the invention according to claim 3 is the color correction table generating method according to claim 1 or 2,
The color data is configured to be gray or a memory color.

[0010] The invention described in claim 4 is the first invention.
4. The color correction table generation method according to any one of Items 3 to 3, wherein a total result in the color correction table generation step is obtained by an average value of color data.

Further, according to a fifth aspect of the present invention, there is provided the color correction table generating method according to any one of the first to third aspects, wherein the totaling result in the color correction table generating step is the color of the maximum frequency. Configured as required by the data.

The invention according to claim 6 is the first invention.
6. The color correction table generation method according to any one of claims 1 to 5, wherein the color data collection step generates a pattern sheet having a plurality of patches in which the amount of each element color is changed in each of a plurality of gradations. A pattern sheet generating step, and a patch selecting step of selecting a desired patch for each tone from a plurality of patches for each tone of the pattern sheet, wherein the color correction table generating step includes: It is configured to generate a color correction table based on the color correction table.

Further, the invention according to claim 7 is the color correction table generating method according to claim 6, wherein the amount of elemental color changed in the pattern sheet generating step is varied according to a gradation. It is composed of

[0014] The invention described in claim 8 is the invention according to claim 6.
Alternatively, in the color correction table generation method described in 7, the amount of the element color changed in the pattern sheet generation step is increased as the gradation becomes lower.

In a ninth aspect of the present invention, there is provided the color correction table generating method according to any one of the sixth to eighth aspects, wherein the amount of the elemental color to be changed in the pattern sheet generating step is changed to the elemental color. It is configured to be different every time.

According to a tenth aspect of the present invention, there is provided an apparatus for generating a color correction table for performing desired color correction on input image data, wherein the color data collecting means collects color data for each region. And a color correction table generating means for generating a color correction table based on the collection result of the color data collecting means.

Further, according to the eleventh aspect of the present invention, the computer-readable recording medium stores a program for causing a computer to execute a process of generating a color correction table for performing desired color correction on input image data. A recording medium for causing a computer to execute a color data collection process of collecting color data for each region, and a color correction table generation process of generating a color correction table based on a collection result in the color data collection process. And the computer is configured to be readable by a computer.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a functional block diagram showing an entire system for generating a color correction table according to an embodiment of the present invention. FIG. 2 is a functional block diagram showing a color correction table generated by the color correction table generating method of the present invention. It is a functional block diagram showing an image processing apparatus that performs a desired color correction using a table,
FIG. 3 is a schematic block diagram illustrating a specific hardware configuration example of the color correction table generation device, the client 10, and the image processing device.

As shown in FIG. 1, a client 10 is connected to the Internet via a provider server 22, and a Web server 24 is connected to the Internet. That is, the client 10 and the web server 24 are connected to each other via the Internet. In this embodiment, only one client is shown, but it is assumed that a plurality of clients can access the web server 24 via the Internet.

The client 10 generates pattern sheet data for adjusting gray balance and storage colors such as flesh color and sky color by an application based on an instruction from the instruction unit 10a.
An image output device 10c for generating a pattern sheet based on the pattern sheet data generated by the pattern sheet generating unit 10b; and a color correction table generating unit for generating color correction table generating data based on an instruction from the instruction unit 10a. It includes a data generator 10e and a communication device 10d for transmitting the data generated by the color correction table generation data generator 10e to the web server 24 via a network. The instruction unit 10a
Is composed of a keyboard, a mouse and other pointing devices.

The web server 14 includes a color correction table generation device 24a and a communication device 24b for communicating with another device via a network. And
The color correction table generation device 24a performs a color correction table (L) for performing a preferred color correction for each region based on the totalization result of the sample data provided from the client 10.
UT), and a color correction LUT for storing the generated color correction LUT
And a storage unit 24d.

Image Processing Apparatus In FIG. 2, an image processing apparatus 20 performs image processing on an image input signal supplied from an image input apparatus such as a scanner or a digital camera, and converts the processed color image data into an image. Output to the output device 30. Here, the image input signal performs color separation of the color image for each predetermined element color,
It expresses the strength of each element color, and is composed of an achromatic color represented by gray and black when it is a chromatic color and mixed at a predetermined ratio.

The image processing apparatus 20 refers to the color correction table read from the color correction table storage section 20d based on the instruction from the instruction section 20e, and converts the input RGB gradation data (the image input signal) into R. An RGB conversion unit 20a that converts the data into G'B 'gradation data;
Is expressed by CMY ((cyan, magenta, yellow) or CMYK with black added thereto, or CM with light cyan (c) light magenta (m) added thereto)
A color conversion unit 20b that converts the data into YKcm) gradation data;
The converted CMY (or CMYK or CMYK
cm) of grayscale data into grayscale data into binary data.

Hardware Configuration A specific example of the image input device is the scanner 11 shown in FIG.
a, digital still camera 11b or video camera 1
1c and the like. A specific example of the image processing apparatus 20 is a computer system including a computer 12, a hard disk 13b, a keyboard 15a, a CD-ROM drive 13c, a floppy (registered trademark) disk drive 13a, a modem 14a, a mouse 15b, and the like. Applicable. A specific example of the image output device 30 corresponds to the printer 17b, the display 17a, and the like. However, in the present embodiment, the printer 17b among these image output devices 30 will be particularly described in detail. The modem 14a is connected to a public telephone line and connected to an external network via the public communication line, and can download software and data.

The color correction table generation processing control program and the image processing control program according to the present invention are usually distributed in a form readable by the computer 12 in a recording medium such as a floppy disk or CD-ROM. The program is a media reader (CD-RO)
M drive 13c, floppy disk drive 13a
Etc.) and installed on the hard disk 13b. The CPU is configured to read a desired program from the hard disk 13b and execute a desired process. The color correction table generation control program and the image processing control program according to the present invention also constitute a part of the present invention.

In this embodiment, a scanner 11a or a digital still camera 11b as an image input device is used.
Outputs RGB (green, blue, red) gradation data as image data, and the printer 17b as the image output device 30 outputs CMY (cyan, magenta, yellow) as gradation data or black to this. CMYK added,
Or light cyan (c) and light magenta (m)
Requires binary data of CMYKcm to which is added. Further, the display 17a requires RGB gradation data as an input. On the other hand, in the computer 12, the operating system 12a, the printer 17
b and a display driver 12b corresponding to the display 17a.
The execution of the image processing application 12d is controlled by the operating system 12a, and executes predetermined image processing in conjunction with the printer driver 12c and the display driver 12b as necessary. Therefore, the computer 1 as the image processing device 20
The specific role of 2 is to adjust the color balance with the output device so that the preferred color correction can be performed for each region, and to input RGB gradation data to perform RGB image gradation processing and optimal image processing. The data is created, converted into CMY (or CMYK or CMYKcm) binary data via the printer driver 12c, and printed by the printer 17b.

Referring now to FIG. 4, a description will be given of a color correction table generation data generation program executed by the client 10 shown in FIG.

In this embodiment, a description will be given of a process of creating data for generating a color correction table reflecting a gray preferred in a predetermined area. The same applies to the data generation processing for generating a color correction table that reflects memory colors such as skin color and sky blue that are preferred in a predetermined area.

First, when a gray balance adjustment is instructed via the instructing unit 10a of the client 10 shown in FIG.
The pattern sheet generation unit 10b generates gray balance adjustment pattern sheet data, and the printer as the image output device 30 prints the gray balance adjustment pattern sheet based on the generated pattern sheet data (step 40). .

FIG. 5 shows an example of a printed pattern sheet. The numbers in each patch constituting the pattern sheet are data of R (red), G (green), B (blue) in order from the top.
(A value corresponding to the amount of each component). However, these numbers are not displayed on the actual pattern sheet.

As shown in FIG. 5, the current gray gradation pattern is displayed on the top row of the pattern sheet. That is, each gradation (A: 28 gradations, B: 56 gradations,
C: 84 tones, D: 112 tones, E: 140 tones, F:
(168 gradations, G: 196 gradations, H: 224 gradations), the colors are displayed when the amounts of the RGB components are all reference amounts (the same).

Also, the second row from the top of the pattern sheet
On the fourth line, a gradation pattern in which the RGB balance is changed is displayed.

The patches constituting the pattern sheet in the second row from the top are configured such that the amount of the B component at each gradation is greater than the reference amount by a different predetermined amount at each gradation. For example, the D gradation indicated by X (112
In the case of (gradation), the amount of the B component of all 9 (= 3 × 3) patches is a value 6 larger than the reference amount 112 of the D gradation 11
8.

The patches constituting the pattern sheet in the third row from the top are configured such that the amount of the B component at each gradation becomes the reference amount at each gradation. For example, Y
In the case of the D gradation (112 gradation), the amount of the B component of all 9 (= 3 × 3) patches is configured to be equal to the reference amount 112 of the D gradation.

The patches constituting the pattern sheet in the fourth row from the top are configured such that the amount of the B component at each gradation is smaller than the reference amount by a different predetermined amount at each gradation. For example, in the case of the D gradation (112 gradation) indicated by Z, the amount of the B component of all 9 (= 3 × 3) patches is a value that is 6 less than the reference amount 112 of the D gradation. It is configured so that

Further, the configuration of 9 (= 3 × 3) patches in each gradation of each of the second to fourth rows will be described. With respect to the three vertical columns, the amount of the R component in the left column is smaller than the reference amount by a predetermined amount different in each gradation, the amount of the R component in the center column is equal to the reference amount in each gradation, and the amount of the R component in the right column is one. The amount of the R component is larger than the reference amount by a different predetermined amount for each gradation. For example, in the case of nine patches indicated by X, the amount of the R component in one row on the left side is smaller than the reference amount (112) by a predetermined amount (6) in the D (112) gradation, and The amount of the component is equal to the reference amount (112) in each gradation, and the amount of the R component in the right column is D
(112) A reference amount (11) by a predetermined amount (6) in gradation
It is configured to be more than 2). Also, horizontal 3
With respect to the row, the amount of the G component in the upper row is greater than the reference amount by a different predetermined amount in each gradation, and the amount of the G component in the center row is equal to the reference amount in each gradation.
The configuration is such that the amount of the G component in the lower row is smaller than the reference amount by a different predetermined amount for each gradation. For example, in the case of nine patches indicated by X, the amount of the G component in the upper one row is larger than the reference amount (112) by the predetermined amount (6) in the D (112) gradation, and When the amount of the component is equal to the reference amount (1
12) and the amount of the G component in the lower row is D (11
2) It is configured to be smaller than the reference amount (112) by a predetermined amount (6) in gradation.

It should be noted that, in step 40, the instruction unit 10
The adjustment width (%) on which the predetermined amount is calculated can be designated by a. FIG. 6 shows an example of a user interface for specifying the adjustment width. In this embodiment, in the user interface shown in FIG.
The adjustment width of each gradation from H to H can be specified for each color within the range of 1 to 10 (%).

Here, the relationship between the adjustment width for each gradation and the predetermined amount (the shift amount of each element color component from the reference amount in a patch of a predetermined gradation) will be described.

Assuming that x (28 to 224) is a gradation value, y is an adjustment width (%), and z (x, y) is the predetermined amount, z (x, y) = (255−x) × y / 100… (1) In equation (1), (255−x) is almost proportional to the amount of ink used. That is, in the high-density area where the amount of used ink is large, the shift amount of each element color component of the patch at the predetermined gradation from the reference amount is increased so that the user can easily recognize the gray patch.

In this embodiment, the adjustment width (y) is set to 4%. The predetermined amount z in the D (112) gradation is:
From equation (1), z (112,4) = (255−112) × 4/100 = 6. Therefore, the value indicating the amount of each component color component of the 27 patches indicated by X, Y, and Z in FIG.
2, 112 + 6 = 118.

It should be noted that the value of the predetermined amount z can be changed for each color by changing the value of y for each element color component.

Next, the printing result of the gray balance adjustment pattern sheet printed in step 40 is visually observed, and for each of the eight gradations A to H, 27 (= 3 × 3 × 3) The user selects the patch considered to be the most gray (achromatic) from the patches by the instruction unit 10a (step 42, Ye).
s). As an example, the same pattern as the printed pattern sheet shown in FIG. 5 is displayed on a display unit (not shown),
Click on the displayed pattern with your mouse, etc.
It may be configured to allow selection of a patch in step 42.

Next, the color correction table generation data generating section 10e generates correction table generation data for each of the RGB colors based on the patch selected by the instruction section 10a (step 44). That is, the values of the RGB components of the selected patches (the values (A to H shown in the patches in FIG. 5)
Are generated as color correction table generation data.

Here, when the instruction unit 10a instructs the printing of the gray balance adjustment result pattern sheet (step 46, Yes), the adjustment result pattern sheet (gray patches in each gradation of A to H) shown in FIG. 7 is printed. (Step 48), the gray balance after the adjustment can be confirmed.

Then, when data transmission is instructed by the instruction unit 10a (step 50, Yes), the R created by the data creation unit 10e for generating a color correction table is created.
The correction table generation data for each color of GB is transmitted to the web server 24 (step 52).

In the present embodiment, the processing for generating data for generating a color correction table reflecting a preferred gray has been described. However, it is preferable to generate and select similar patches for memory colors such as skin color and sky blue. It is possible to create color correction table generation data that reflects a memory color such as a flesh color or a sky color.

Next, a color correction table generation processing program executed by the color correction table generation device 24a shown in FIG. 1 will be described with reference to FIG.

First, the color correction table generation unit 24c of the color correction table generation device 24a totals the color correction table generation data transmitted from the client 10 via the Internet for each region (step 60). Then, the color correction table generation unit 24c calculates the average value of the RGB component values (the values shown in the patches in FIG. 5) of each selected patch for each gradation (step 62). The average value is used as a correction value at each gradation point of A to H.

Next, the color correction table generator 24c generates a color correction table for each color based on the correction values at the respective gradation points A to H obtained in this way (step 64). The color correction table generation unit 24c
The correction values other than the gradation points H to H are obtained by connecting the gradation points with a spline curve.

The color correction table thus generated is stored in the color correction table storage 24d (step 66).

As described above, it is possible to generate the color correction table reflecting the gray preference for each area.

In the present embodiment, in step 62, the color correction table generation unit 24c
The average value of the RGB component values (the values shown in the patches in FIG. 5) of each selected patch is calculated, and the average value is used as a correction value at each gradation point of A to H. Alternatively, the values of the RGB components of the patches most frequently selected in the predetermined area may be used as the correction values at the gradation points A to H.

An image processing program executed by the image processing apparatus 20 will be described below with reference to FIG. In the present embodiment, it is assumed that the color correction table generated by the color correction LUT generation method is stored in the color correction LUT storage unit 20d in advance.

As shown in FIG. 8, the color correction unit 2 shown in FIG.
When the user selects a color correction table reflecting gray preference in a predetermined area by the instruction unit 20e (step S80, Yes), the user reads out the selected color correction table from the color correction LUT storage unit 20d and stores it in the RAM. (Step S84). Then, the color correction table is incorporated into the color correction unit 20a (Step S86),
Printing processing is performed (step S90).

In this embodiment, the color correction L according to the present invention is used.
It is assumed that the color correction table generated by the UT generation method is stored in the color correction LUT storage unit 20d in advance. However, the color correction table may be downloaded from the web server 24.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing an entire system for generating a color correction table according to an embodiment of the present invention.

FIG. 2 is a functional block diagram illustrating an image processing apparatus that performs desired color correction using a color correction table generated by the color correction table generation method of the present invention.

FIG. 3 is a schematic block diagram illustrating a specific hardware configuration example of a color correction table generation device, a client, and an image processing device according to the present invention.

FIG. 4 is a flowchart illustrating a color correction table generation data generation processing program executed by a client 10;

FIG. 5 is a diagram illustrating an example of a gray balance adjustment pattern sheet.

FIG. 6 is a diagram illustrating an example of a user interface for specifying an adjustment width.

FIG. 7 is a diagram illustrating an example of an adjustment result pattern sheet.

FIG. 8 is a flowchart for explaining an image processing program executed by the image processing apparatus 20.

FIG. 9 is a flowchart for explaining a color correction table generation processing program executed by the color correction table generation device 24a.

[Explanation of symbols]

 Reference Signs List 10 client 10a instruction unit 10b pattern sheet generation unit 10c image output device 10d communication device 10e color correction LUT generation data generation unit 11a scanner 11b digital still camera 11c video camera 12 computer body 12a operating system 12b display driver 12c printer driver 12d application 13a Floppy disk drive 13b Hard disk 13c CD-ROM drive 14a Modem 15a Keyboard 15b Mouse 17a Display 17b Color printer 20 Image processing unit 20a Color correction unit 20b Color conversion unit 20c Binarization unit 20d Color correction LUT storage unit 20e Instruction unit 22 Provider Server 24 Web server 24a Color correction table generator 24b Communication Device 24c color correction LUT generator 24d color correction LUT storage unit 30 an image output device

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference) 2C262 AA24 AA26 AA30 AB11 AB17 BA09 BB03 BB36 BC01 BC07 BC10 FA13 GA59 5B057 AA11 BA02 CA01 CA08 CA12 CA16 CB01 CB08 CB12 CB16 CC01 CE17 CE18 CH07 CH08 5C077 LL19 MM27PP PQ12 PQ23 SS02 TT02 TT06 5C079 HB01 HB03 HB12 LA02 LA31 LB02 MA05 MA10 NA03

Claims (11)

[Claims] 1. A method for generating a color correction table for performing desired color correction on input image data, comprising: a color data collection step of collecting color data for each area; A color correction table generating step of generating a color correction table based on the result. 2. The color correction table generation method according to claim 1, wherein the collection of the color data in the color data collection step is performed via the Internet. 3. The color correction table generation method according to claim 1, wherein the color data is gray or a memory color. 4. The color correction table generation method according to claim 1, wherein a totaling result in the color correction table generation step is obtained by an average value of color data. . 5. The color correction table generation method according to claim 1, wherein a totaling result in the color correction table generation step is obtained based on color data of a maximum frequency. . 6. The color correction table generation method according to claim 1, wherein the color data collection step comprises: changing a quantity of each component color in each of a plurality of gradations. A pattern sheet generating step of generating a pattern sheet having a patch; and a patch selecting step of selecting a desired patch for each gradation from a plurality of patches for each gradation of the pattern sheet. A method for generating a color correction table, wherein the process generates a color correction table based on a selected patch. 7. The color correction table generation method according to claim 6, wherein an amount of an element color to be changed in the pattern sheet generation step is varied according to a gradation. 8. The color correction table generation method according to claim 6, wherein the amount of element colors changed in the pattern sheet generation step is increased as the gradation becomes lower. 9. The color correction table generation method according to claim 6, wherein an amount of an element color to be changed in the pattern sheet generation step is different for each element color. Method. 10. A color correction table generating apparatus for performing a desired color correction on input image data, comprising: a color data collection unit that collects color data for each region; A color correction table generation unit that generates a color correction table based on the result. 11. A computer-readable recording medium storing a program for causing a computer to execute a process of generating a color correction table for performing desired color correction on input image data, wherein A color data collection process for collecting color data, and a color correction table generation process for generating a color correction table based on the collection result in the color data collection process. Recording media