JP2002057912A - Image processor and image forming device provided with it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processor and an image forming device by which user can grasp an entire distribution state of color image data, easily estimate an output result and obtain an image preferred by the user. SOLUTION: In the image processor provided with a color correction section 210 that converts color image data of a 1st colorimetric system into color image data of a 2nd colorimetric system, the color correction section 210 is provided with a differential arithmetic section 215 and a correction processing section 216 as color correction means that conduct color correction processing. The image processor conducts color correction processing based on distribution information of the color image data of the 1st colorimetric system displayed on a distribution information display section 221 provided to an operation panel 22 of a digital color copying machine, and furthermore applies color correction to an optional area selected among areas of the color image data of the 1st colorimetric system by an area selection section 223 provided to the operation panel 220.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus, and more particularly to an image processing apparatus for modifying a color image and an image forming apparatus having the same.

[0002]

2. Description of the Related Art In recent years, digitalization of OA equipment has rapidly progressed, and demand for color image output has increased, so that digital color copying machines of an electrophotographic system and color printers of an ink jet system and a thermal transfer system have been developed. It has been widely spread. For example, image information input from an input device such as a digital camera or a scanner, or image information created on a computer is output using these output devices. Also, for general users,
It is not uncommon for various printers and copiers to be able to output color images, and to print image data taken by digitizing photographs.

When outputting image information in this way, the image information may be modified depending on the user's preference. As a method of modifying the image information, the input image data is converted into L ^* a ^* b ^* color space data representing color information that directly appeals to human vision, and the numerical values and the like of each component are changed. The fix has been made.

For example, as disclosed in Japanese Patent Application Laid-Open No. 9-97319, a reference circle is displayed on an a ^* b ^* plane, and the hue is changed by moving the position of the reference circle, thereby increasing the size. There has been proposed a method of modifying the image data by creating a conversion curve of a ^* data / b ^* data based on the change of the reference circle, in which the saturation changes when the image data is changed.

[0005]

SUMMARY OF THE INVENTION However, RGB
In a modification method using a color space such as L ^* a ^* b ^* or a tone curve, there is a problem that such a concept of the color space is not general to the user, and the correction result is difficult to understand. In addition, there is a problem that processing by complicated correction means is required, and the system becomes complicated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and it is possible to grasp the overall distribution of color image data with a simple configuration, to easily estimate an output result, and to easily perform color analysis. It is an object of the present invention to provide an image processing apparatus capable of performing color modification and color modification of an arbitrary area, and an image forming apparatus including the image processing apparatus.

[0007]

According to the present invention, there is provided an image processing apparatus for converting color image data having a first color system into a second color image data.
In an image processing apparatus including a color correction unit that converts color image data of a color system, the color correction unit,
The image processing apparatus further includes a color adjustment unit that performs color adjustment based on distribution information of a distribution information display unit that displays distribution information of color image data having a first color system.

Further, in the present invention, the color correcting means may include a first color correcting means.
It is preferable to perform color correction on the area selected by the area selecting means for selecting an arbitrary area of the color image data having the color system.

[0009] The color retouching means may be a distribution of a ^* -b ^* planes based on the chromaticity a ^* · b ^* of the color image data of the first color system displayed on the distribution information display means. It is preferable to perform the color modification processing based on the information.

[0010] It is preferable that the color retouching means performs color retouching processing based on distribution information of a lightness-saturation plane of color image data of the first color system displayed on the distribution information display means. .

[0011] The color modifying means may be configured to display a color based on distribution information of a lightness-chroma plane and an a ^* -b ^* plane of color image data of the first color system displayed on the distribution information display means. It is preferable to perform a modification process.

The color modifying means divides a brightness-chroma plane (space) of the color image data of the first color system displayed on the distribution information display means into a plurality of color direction ranges. Brightness within the range of the selected color direction-
It is preferable to perform the color modification processing based on the saturation plane distribution information.

[0013] The color modifying means may convert the lightness-chroma plane (space) of the color image data of the first color system displayed on the distribution information display means into a color selected by the hue angle h. It is preferable to perform the color correction processing based on the distribution information of the brightness-saturation plane in the direction range.

[0014] The color retouching means may perform a color retouching process based on distribution information of a plurality of a ^* -b ^* planes of the color image data of the first color system displayed on the distribution information display means. Is preferably performed.

[0015] The color retouching means may be a color retouching unit which is displayed on the distribution information display means, based on distribution information of an a ^* -b ^* plane at an arbitrary lightness value of the color image data of the first color system. Preferably, a treatment is performed.

[0016] Further, the color modifying means may include the distribution information table.
A color image composed of a first color system displayed on the display means
Data is divided by an arbitrary brightness value, and the divided range
A ^*-B^*Performing color modification processing based on plane distribution information
Is preferred.

The color modifying means may perform color modifying processing based on distribution information of a plurality of lightness-chroma planes of the color image data of the first color system displayed on the distribution information display means. Is preferred.

Further, the color modifying means is inputted based on distribution information on a brightness difference-saturation difference plane of color image data of the first color system displayed on the distribution information display means. It is preferable to include a calculation unit that performs a color correction process based on the difference data.

Further, the arithmetic means performs an arithmetic operation for color correction based on the coordinates on the brightness difference-chroma difference plane of the color image data of the first color system. It is preferable to perform the processing over color image data.

Further, the calculating means is configured to select an operation for color correction based on coordinates on a brightness difference-chroma difference plane of the color image data of the first color system based on the selected brightness / hue range. It is preferable to perform the processing for color image data having the first color system. In addition, it is preferable that the image processing apparatus described above is provided in the image forming apparatus.

According to the present invention, the color adjustment is performed based on the brightness difference and the saturation difference information of the color image data of the first color system, and the distribution status of the color image data of the first color system is displayed. By using the distribution information display means provided on the operation panel of the image forming apparatus, the output result can be easily estimated, and an image more preferred by the user can be obtained.

The color correction means for converting the color image data of the first color system into the color image data of the second color system includes a distribution information of the color image data in the first color system. And a color correction unit for performing a color correction process based on the distribution information of the distribution information display unit for displaying an image. Further, an area selection unit for selecting an arbitrary region of the color image data having the first color system is formed. By providing it on the operation panel of the apparatus, it is possible to adjust the color of an arbitrary area. Since this color adjustment is performed by using a difference calculation between the lightness difference and the saturation difference, the processing can be easily performed, and the circuit configuration can be simplified.

Also, the distribution information display means can be used for the first
RGB image data, which is color image data of the color system, is converted into image data of the L ^* a ^* b ^* color system, and a ^* -b
^* By displaying the distribution status (distribution information) on the plane, it is possible to grasp the status of the parameters corresponding to the hue that does not depend on lightness, such as red, orange, yellow, green, blue, purple, etc. can do.

The distribution information display means displays the distribution status on the lightness-saturation plane based on the lightness / saturation obtained from the L ^* a ^* b ^* image data. It is possible to grasp the overall distribution of color image data (L ^* a ^* b ^* color system image data) composed of the first color system and to consider the balance of the entire image in the process of color correction. it can. Further, it is possible to grasp the distribution state of a parameter corresponding to light, dark, bright, dark, vivid, dull, etc., which does not depend on the hue, among the parameters representing colors.

Also, the distribution information display means can be used to set the first
The color space can be expressed two-dimensionally by displaying the information on the distribution status on the brightness-chroma plane and the distribution status on the a ^* -b ^* plane of the color image data composed of the color system It is possible to assume a color space from a simple viewpoint, and to grasp the overall distribution of color image data composed of the input first color system so as to balance the entire image in the process of color correction. Can be considered.

Also, the distribution information display means can be used to set the first
The lightness-saturation plane of the color image data having the color system of a plurality of color directions, and six ranges of red, orange, yellow, green, blue, and purple directions as representative colors by hue angle h, h (red direction) ) <
By setting and displaying in advance such that ± 20 °, 80 ° <h (yellow direction) <100 °, adjustment can be easily performed for general users who are not familiar with the color relationship.

[0027] The distribution information display means may provide a first information.
By displaying the lightness-saturation plane distribution of the color direction directly selected by the hue angle h on the lightness-saturation plane of the color image data composed of the color system, the color other than the representative color is color-corrected in detail. In this case, the range of the desired color direction can be designated by the hue angle h to display a lightness-chroma plane.

The distribution information display means provides a ^*
-B ^* By arbitrarily displaying a plurality of distribution states on the plane, the state of the range at each brightness can be represented by, for example, L ^* = 5.
The a ^* -b ^* plane distribution at 0 and 70 can be simultaneously grasped.

Further, the distribution information display means provides a ^*
By displaying the distribution state on the −b ^* plane at an arbitrary lightness value, the distribution state at each lightness can be grasped.

The distribution information display means provides a ^*
By displaying the distribution status on the -b ^* plane for each lightness value width, the distribution status in each lightness range can be grasped.

Further, the distribution information display means arbitrarily displays a plurality of distribution states on the lightness-chroma plane, so that the parameters representing the colors do not depend on the hue.
For example, the distribution state of a range corresponding to light, dark, bright, dark, dull, etc. is simultaneously grasped, for example, a lightness-chroma plane in the blue-yellow direction and a lightness-chroma plane in the green-red direction. be able to.

Further, the color correcting means performs an operation for color correcting based on the distribution information of the color image data of the first color system displayed on the distribution information displaying means, by a lightness difference-chroma difference plane. By providing the arithmetic means for performing the above-described difference operation, the operation for color correction can be simplified.

Further, the arithmetic means performs a difference operation for the color adjustment based on the coordinates on the lightness difference-saturation difference plane, whereby the color image composed of all the first color systems is obtained. Color correction of data becomes possible.

Further, the arithmetic means performs an operation on the color image data of the first color system in the selected range on the a ^* -b ^* plane, so that the color data of the first color system can be obtained. The difference correction can be performed on the selected specific range, not the entire image data, using the lightness difference-saturation difference plane, and color correction can be performed.

Further, by providing the above-described image processing apparatus, it is possible to provide an image forming apparatus capable of performing color correction of an arbitrary area by a simple color correction method.

[0036]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram illustrating an example of a configuration of a digital color copying machine (image forming apparatus) including a color image processing apparatus to which a color image processing method and a color image processing apparatus according to an embodiment of the present invention are applied.

In the present embodiment, as shown in FIG.
Conversion unit 10, shading correction unit 11, input gradation correction unit 12, region separation processing unit 13, color correction unit 14, black generation and under color removal unit 15, spatial filter processing unit 16, output gradation correction unit 17, and floor A digital color copying machine 4 is configured by connecting a color image processing apparatus 1 having a tone reproduction processing section 18, a color image input apparatus 2 and a color image output apparatus 3.

The color image input device 2 as an image reading means is, for example, a CCD (charge coupled).
A scanner unit (not shown) having a device (device) is provided.
Red, G: green, B: blue) analog signals are read by a CCD and input to the color image processing apparatus 1.

The analog signal read by the color image input device 2 is output to the color image processing device 1 as shown in FIG.
A / D conversion unit 10, shading correction unit 11, input gradation correction unit 12, region separation processing unit 13, color correction unit 14, black generation and under color removal unit 15, spatial filter processing unit 16, output gradation correction unit 17 , And the tone reproduction processing unit 18 in this order,
It is output to the color image output device 3 as a CMYK digital color signal.

A / D (analog / digital) converter 10
Converts an RGB analog signal into a digital signal.

The shading correction unit 11 is provided with the A / D
The digital RGB signal sent from the conversion unit 10 is subjected to processing for removing various types of distortion generated in the illumination system, the imaging system, and the imaging system of the color image input device 2.

The input tone correction section 12 is a section in which various distortions have been removed in the shading correction section 11.
A color image processing device 1 such as a density signal while adjusting the color balance with respect to the signals (RGB reflectance signals)
In this case, the image is converted into a signal which can be easily handled by the image processing system employed in the first embodiment.

The area separation processing section 13 separates each pixel in the input image into any of a character area, a halftone area, and a photograph area from the RGB signals. Is output to the black generation and under color removal unit 15, the spatial filter processing unit 16, and the tone reproduction processing unit 18, and the input tone correction unit 12
The input signal output from the color correction unit 14 is
Output to

The color correction unit 14 performs a process of removing color turbidity based on the spectral characteristics of CMY (C: cyan, M: magenta, Y: yellow) color materials containing unnecessary absorption components in order to faithfully reproduce colors. Do. Further, in the image processing apparatus 1 of the present invention, the color correction unit 14 can perform a process of modifying image information.

The black generation and under color removal section 15 outputs the CM after color correction.
The CMY is a process for generating a new CMY signal by subtracting the K signal obtained by the black generation from the original CMY signal from black generation for generating a black (K) signal from three Y color signals.
Are converted into CMYK four-color signals.

As an example of the black generation processing, there is a method (general method) of performing black generation using skeleton black. In this method, the input / output characteristics of the skeleton curve are represented by y = f
(X), input data is C, M, Y, output data is C ', M', Y ', K', UCR (Under
If the Color Removal rate is α (0 <α <1), the black generation and under color removal processing is represented by the following equation (1).

The spatial filter processing unit 16 performs a spatial filter process on the image data of the CMYK signal input from the black generation and under color removal unit 15 using a digital filter based on the region identification signal to correct the spatial frequency characteristics. By doing so, processing is performed so as to prevent "blur" and deterioration of graininess of the output image.

Similarly to the spatial filter processing section 16, the tone reproduction processing section 18 performs predetermined processing on the image data of the CMYK signal based on the area identification signal.

For example, in the area separation processing section 13, the area separated into characters is subjected to a sharp emphasis processing in the spatial filter processing by the spatial filter processing section 16 in order to enhance the reproducibility of a black character or a color character. Is increased. At the same time, the tone reproduction processing section 18 selects binarization or multi-value processing on a high-resolution screen suitable for reproduction of a high frequency.

Further, for the area separated into halftone dots by the area separation processing section 13, the spatial filter processing section 16 performs a low-pass filter processing for removing an input halftone dot component. Then, the output tone correction unit 17 performs an output tone correction process of converting a signal such as a density signal into a dot area ratio which is a characteristic value of the color image output device 3,
The tone reproduction processing section 18 performs a tone reproduction process (halftone generation) for finally separating an image into pixels and performing processing so that each tone can be reproduced. For the regions separated into photographs by the region separation processing unit 13, binarization or multi-value processing is performed on a screen that emphasizes tone reproducibility.

The image data subjected to each of the above-described processes is
The data is temporarily stored in the storage unit, read out at a predetermined timing, and input to the color image output device 3. The image output device 3 outputs image data on a recording medium (for example, paper), and includes, for example, a color image forming apparatus using an electrophotographic system or an inkjet system, but is not particularly limited. Not something.

When the image output device 3 is constituted by a display device such as a CRT or a liquid crystal display, the black generation and under color removal unit shown in FIG. 1 is unnecessary, and the color correction unit RGB → R ′.
Conversion processing to G'B 'is performed. Note that the above processing is not shown in the CPU (Central Processing).
Unit).

Next, Embodiment 1 of the present invention will be described with reference to the drawings.
And will be described in detail. FIG. 2 shows the first embodiment of the present invention.
FIG. 3 is a block diagram of a color correction unit (color correction means), and FIG.
FIG. 4 is a flowchart showing the image data processing procedure of the main part,
Is a color correction strip displayed on the operation input unit of the image forming apparatus.
FIG. 5 is an explanatory view showing an example of an input screen of a case, and FIG.
Displayed on the distribution information display section (distribution information display means) of the device
Brightness difference (ΔL^*) -Saturation difference (ΔC^*)
FIG. 6 is an explanatory view showing an example, and FIG. 6 is displayed on the distribution information display section.
A of the input image data having the first color system^*-B^*Plane
(All L^*Screen for inputting distribution information and correction processing conditions
FIG. 7 is an explanatory diagram showing an example of the distribution information display section.
L of the input image data of the first color system ^*-C^*
Input image of distribution information of planes (all h values) and correction processing conditions
FIG. 8 is an explanatory view showing an example of a surface, and FIG.
A of input image data having the first color system shown^*−
b^*Plane (all L^*Value) distribution information and correction processing conditions
FIG. 9 is an explanatory diagram showing an example of a force screen, and FIG.
L of the input image data composed of the first color system displayed on
^*-C^*Distribution information of plane (all h values) and correction processing conditions
FIG. 4 is an explanatory diagram illustrating an example of an input screen.

As shown in FIG. 2, the color correction section 100 of the first embodiment includes a color correction difference calculation section (calculation means) 106 and a correction section 107 as color correction means for performing color correction processing. A color correction processing is performed based on distribution information of color image data of the first color system displayed on a distribution information display section (distribution information display means) 110 provided on an operation panel 160 of a copying machine (image forming apparatus). It is.

The color correction unit 100 receives color image data (RGB image data) of the first color system from the color image input device 2 such as the scanner. As shown in FIG. 2, the color correction unit 100 includes a distribution information calculation unit 109 that calculates data necessary for the distribution information display unit 110, and a L ^* C ^* h color system through the distribution information calculation unit 109. An L ^* C ^* h conversion unit 102 for conversion;
L that branches L ^* C ^* h converted into L ^* , C ^* and h
^* , C ^* / h branching unit 103, a modification input confirmation unit 105 for confirming the operation of an operation input unit 104 for inputting a color modification condition by a lightness difference and a saturation difference, and the operation input unit 104
Based on the difference data of the brightness difference and the saturation difference input by
L ^*, color retouching difference computing unit which performs correction calculation of C ^* data (color modification means, computing means) the and 106, L ^* corrected by the color modification difference calculation unit 106, the C ^* data L ^*, C ^*
A correction unit (color correcting means) 107 for accumulating the h data branched by the / h branching unit 103, a checking unit 108 for checking whether a series of color correcting has been completed, and a color correcting completion checking unit 1
08, the L ^* C ^* h color system image data is temporarily converted to L ^* a ^* b ^* color system image data, and then converted to CMY data, which is the second color system color image data. And a color coordinate calculation unit 111.

As shown in FIG. 4, the operation input unit 104 includes, as an example of a color adjustment condition on the lightness difference-saturation difference plane, a visual color such as bright-dark, light-dark, vivid-dark. A display unit 104a represented by a display axis is provided.

In FIG. 4, if the user desires two parameters such as a "bright" + "bright" image at the same time, point A in the figure is selected. Assuming that the coordinates of the point A on the lightness difference-saturation difference plane are (+ p, + q), the difference data is that C ^* is + p and L ^* is + q.

Next, the image data processing by the color correction unit 100 will be described with reference to the block diagram of FIG. 2 and the flowchart of FIG. First, when the image data processing is started, in S1, the color image data of the first color system input to the distribution information calculation unit 109 is converted into the L ^* a ^* b ^* color system. Further, when the L ^* -C ^* plane is used for the distribution information, an operation for converting to the L ^* C ^* h color system is performed based on the following equation (2). However, L ^* , a ^* , and b ^* are L ^* a ^* b ^* color systems (CIE197
6) Space coordinates in the uniform color space. Here, calculations necessary for displaying the distribution information are performed.

In S2, based on the result calculated in S1,
The distribution information is displayed on the panel of the distribution information display unit 110. Details will be described later.

In S3, the L ^* a ^* b ^* color system color image data is converted by the L ^* C ^* h conversion unit 102 into L ^* C ^* h color system color image data.

In S4, the L ^* C ^* h data converted in S3 is separated into L ^* , C ^* and h in the L ^* , C ^* / h branching unit 103, and L ^* and C ^* are converted into S ^* in S5. H is sent to the modification input confirmation unit 105, and h is transferred to the correction unit 107 in S8.

At S5, based on the color adjustment conditions based on the brightness difference and the saturation difference displayed on the brightness difference-saturation difference plane, the information of the brightness difference and the saturation difference is obtained from the information input by the user through the operation input unit 104. Obtain difference data. Then, the difference data is transferred to the color modification difference calculation unit 106. At this time, the presence / absence of operation of the operation input unit 104 is simultaneously confirmed, and information on operation / non-operation is transferred to the modification input confirmation unit 105 in S6.

In S 6, if the operation is performed based on the operation / non-operation information transferred by the operation input unit 104, the L ^* and C ^* data are transferred from the modification input confirmation unit 105 to the color modification difference calculation unit 106. , When not operated, the correction unit 1
07 respectively.

In S7, the color correction difference calculation unit 106 uses the color correction difference data transferred from S6 to calculate L ^* ,
A difference operation is performed on the C ^* data. For example, assuming that the color-corrected difference data is ΔL ^* = + pΔC ^* = + q, the calculated data L ^* ′ and C ^* ′ are L ^* ′ = L ^* + pC ^* ′ = C ^* + q. After the calculation, the process proceeds to S8, where data L ^* ′,
C ^* 'is transferred to the correction unit 107.

In S9, the color adjustment completion confirmation unit 108 checks whether the above-described series of color adjustment has been completed. If the completion is not confirmed, the flow returns to the calculation of the distribution information in S1 again, and if the completion is confirmed, the data L ^* , C ^*
Is transferred to the color coordinate calculation unit 111 and converted into CMY data. Thus, a series of color modification processing ends.

Next, distribution information will be described. The distribution information is to cumulatively display the data transferred from the distribution information calculation unit 119. For example, if the distribution information is a ^* −
In the case of a b ^* plane (corresponding to claims 3, 8, 9 and 10)
Is transferred L ^* a ^* b ^* within the image data of the color system a ^*,
The b ^* value is displayed as it is on the a ^* -b ^* plane. When an L ^* value range is specified as in claims 9 and 10, a ^* and b ^* values corresponding to the selected L ^* value range are defined as a ^* −.
b ^* Display on a plane.

When the distribution information is on the L ^* -C ^* plane (claims 4, 6, 7, 11), the transferred data is
^* , C ^* , h, and convert the L ^* , C ^* values to L ^* −
Display on C ^* plane. In the sixth aspect, the range of the representative colors red, yellow, green, blue, and purple is defined by the hue angle h.
(Red direction) <± 20 °, 80 ° <h (yellow direction) <1
It is set in advance such as 00 °, and the L ^* and C ^* values in the selected range are displayed on the L ^* -C ^* plane.

[0068] Incidentally, in the distribution information display section (a ^* -b ^* when a plane), if a ^* -b ^* same coordinate values on a plane overlap, depending on their frequency, for example, in Table 1 As shown, the status of accumulation of data may be displayed in detail by changing colors or symbols.

[Table 1]

The operation input unit 104 includes, for example,
As shown in FIG. 5, the operation input unit 114 in which a numerical value is made to correspond to the visual color table axis may perform color adjustment by inputting the numerical value. Further, by arranging the operation surfaces in a layer on the display unit, it is possible to accurately correct the sense color. Note that the configuration of the display unit shown in FIG. 5 is an example of the distribution information display unit, and is not limited to this.

Hereinafter, other display examples of the distribution information of the operation input unit 104 will be described with reference to the drawings. FIG. 6 is a combination example including an a ^* -b ^* plane 121 as a distribution information display unit on the left side of the panel 120 and an operation input unit 124 on the right side. The a ^* -b ^* plane 121 is a distribution of a ^* and b ^* distribution values over all L ^* values of color image data (image data of the L ^* a ^* b ^* color system) composed of the first color system. The situation is shown cumulatively on a plane. With reference to this distribution plane, it is possible to perform a modified input in the operation input unit 124.

FIG. 7 shows an L ^* -C ^* plane 131 as a distribution information display section on the left side of panel 130 and an operation input section 1 on the right side.
34 is an example of a combination including: The L ^* -C ^* plane 131 is provided with color image data (L
^* a ^* b ^* color system image data) C over all L ^* values
^This is the cumulative distribution status of ^{* on} the screen. With reference to this distribution plane, it is possible to perform a modified input in the operation input unit 134.

FIG. 8 shows an a ^* -b ^* plane 141 as a distribution information display section on the left side of panel 140 and an operation input section 1 on the right side.
This is an example of a combination provided with No. 44 (corresponding to claim 9). The a ^* -b ^* plane 141 is a brightness value (L ^* ) selection unit 145 located at the lower center of the panel. The display unit 145a for displaying the brightness value and a ^* , b for the L ^* value selected by the setting button 145b. ^* The distribution of values is shown on the screen cumulatively. With reference to this distribution plane, it is possible to perform a modification input in the operation input unit 144. Further, the brightness value (L ^* ) selecting means 14 in the figure is used.
5 is changed so that an arbitrary brightness range can be selected, a modified example corresponding to claim 10 is obtained.

FIG. 9 shows an example of a combination in which an L ^* -C ^* plane 151 is provided on the left side of the panel 150 as distribution information, and an operation input section 154 is provided on the right side. The L ^* -C ^* plane 151 accumulates the distribution of L ^* and C ^{* with} respect to the h value selected by the display unit 155a and the setting button 155b as the hue value (h) selection means 155 at the lower center of the panel. This is shown on the screen. Reference numeral 155c in the figure is a color display unit that displays a color. With reference to this distribution plane, it is possible to perform a modified input in the operation input unit 154.

Further, by changing the hue value (h) selecting means 155 in the figure so that the hue angle width corresponding to the range of the representative colors of red, yellow, green, blue and purple can be selected.
This is a modified example corresponding to claim 6.

The above-described embodiment is merely an example.
The arrangement of the display units and the selection means, the area of the display unit, the display mode (color, monochrome), and the like are not limited to the examples of the first embodiment.

Next, a second embodiment of the present invention will be described in detail with reference to the drawings. FIG. 10 is a block diagram illustrating a configuration of a color correction unit (color correction unit) and an operation panel of the image processing apparatus according to the second embodiment of the present invention. FIG. 11 is a flowchart illustrating a procedure of processing image data by the color correction unit. 12 is a flowchart showing a color correction processing procedure of the color correction unit, FIG. 13 is an explanatory diagram showing an example of a color correction condition input screen displayed on an operation input unit of the image forming apparatus, and FIG. Lightness difference (ΔL) displayed on the distribution information display section of
^*) - chroma difference ([Delta] C ^*) explanatory diagram showing an example of a color tone diagram showing a, 15 a first input image data comprising color system a ^* -b displayed on the distribution information display section ^* Plane (all L
FIG. 16 is an explanatory diagram showing an example of an input screen for inputting distribution information of ^* value) and correction processing conditions. FIG. 16 shows an L ^* -C ^* plane of input image data composed of a first color system displayed on the distribution information display section. FIG. 17 is an explanatory diagram showing an example of an input screen for (all h values) distribution information and correction processing conditions. FIG. 17 shows a ^*-of input image data of the first color system displayed on the distribution information display section. FIG. 18 is an explanatory view showing an example of an input screen for inputting distribution information of the b ^* plane (all L ^* values) and correction processing conditions. FIG. 18 shows input image data of the first color system displayed on the distribution information display section L ^* −
FIG. 19 is an explanatory view showing an example of an input screen for inputting distribution information of the C ^* plane (all h values) and correction processing conditions. FIG. 19 shows a screen used for identifying a region in the method of selecting a region used in the present invention. FIG. 9 is a diagram for explaining a spatial filter process performed.

As shown in FIG. 10, the color correction section 210 of the second embodiment includes a difference calculation section (calculation means) 215 and a correction processing section 216 as color correction means for performing color correction processing. A color modification process is performed based on the distribution information of the color image data having the first color system displayed on the distribution information display unit (distribution information display unit) 221 provided on the operation panel 220 of the image forming apparatus (image forming apparatus).
The color adjustment is performed on an arbitrary area of the color image data having the first color system selected by the area selection unit (area selection unit) 223 provided on the operation panel 220.

As shown in FIG. 10, the color correction section includes a first color coordinate conversion section 211, a modified input confirmation section 212, and L ^*.
C ^* h conversion section 213, L ^* C ^* / h separation section 214, difference calculation section (color correction means, calculation means) 215, correction processing section (color correction means) 216, correction completion confirmation section 217, L ^* a ^* b ^*
It comprises a conversion unit 218 and a second color coordinate conversion unit 219.

The first color coordinate converter 211 corresponds to the “distribution information calculator” in the first embodiment, and converts input image data (RGB data) of the first color system into L ^* a ^* b.
^* Color system (CIE1976) (CIE: Commiss)
ion Internationale de l'E
claage (International Commission on Illumination), L ^* : lightness, a ^*
B ^* : chromaticity) is converted into image data of a color system (image data of a first color system).

The color coordinate conversion in the first color coordinate conversion section 211 is performed by the following method. i) Each color patch of the color chart document is measured with a colorimeter to determine an L ^* a ^* b ^* value (determining L ^* a ^* b ^* color system data). ii) The color chart original used for color measurement is read from a color image input device to obtain RGB data. iii) Based on the L ^* a ^* b ^* values and the RGB values thus obtained, a coefficient for associating the two is obtained by a neural network or a masking operation coefficient determination method, and color coordinate conversion is performed using the obtained coefficient. I do.

The modification input confirmation unit 212 determines whether or not to perform color modification (operation / non-operation) and determines which signal is being input. Whether or not to perform color correction is shown in FIG.
As shown at 0, the user inputs from the operation panel 220 provided in the digital color copying machine 4. For example, whether or not to perform color correction (or whether or not to perform further correction) is displayed on the distribution information display unit 221 composed of a liquid crystal display or the like, and is selected by a user using a button or a mouse.

The L ^* C ^* h conversion unit 213 converts L ^* a ^* b ^* color system data into L ^* C ^* h color system data (color image data composed of the first color system). Is what you do. Here, C ^* represents the saturation and h represents the hue, and can be obtained by the following equations.

(Equation 1)

The L ^* C ^* / h separation unit 214 corresponds to the “L ^* C ^* / h branching unit” in the first embodiment,
The data of the L ^* C ^* h color system is divided into L ^* C ^* data and h data. The L ^* C ^* data separated by the L ^* C ^* / h separation unit 214 is output to the difference calculation unit 215 corresponding to the “color-correction difference calculation unit” in the first embodiment, and the h data is output to the correction processing unit. Is output.

The difference calculation unit 215 is provided in FIG.
As shown in (1), a difference calculation is performed based on a value input by a user from an input screen 222a displayed on a display unit of the operation input unit 222.

As shown in FIG. 14, the input screen 222a is a diagram (color tone diagram) 222 of the lightness difference ΔL ^* −the saturation difference ΔC ^* .
The coordinate value of the point is input to the difference calculation unit 215 when the user specifies how to correct the image using a mouse or the like.

For example, when the user brightens the original image,
In the case of modifying the image into a vivid image, as shown in FIG. 13, a point A (p, q) on the input screen 222a in a direction to improve the brightness and vividness may be selected. Accordingly, ΔL ^* = + pΔC ^* = + q, and the calculated data L ^* ′, C ^* ′ are L ^* ′ = L ^* + pC ^* ′ = C ^* + q.

If the lightness L ^* or hue h to be subjected to color correction in the above processing is selected by the user (for details, see the following description and FIGS. 17 and 18),
A difference operation is performed on the specified lightness L ^* or hue h. At this time, the value of the lightness or the value of the hue is L
₀ and h ₀ are input to the correction processing unit 216.

The correction processing section 216 obtains data of the L ^* C ^* h color system to be output based on the result of the difference operation (including the presence or absence of designation of the lightness L ^* or the hue h). . When a difference operation is performed by designating lightness or hue, a plurality of values may be designated in addition to one lightness or hue. Therefore, as shown in FIG. 10, the data of the L ^* C ^* h color system output from the correction processing unit 216 is represented as L ^* 'C ^* ' h 'data including these.

The correction completion confirmation section 217 confirms whether or not a signal for performing color correction has been input. Further, whether or not to perform color correction is determined by the operation panel 220.
Determined by the user input from

The L ^* a ^* b ^* conversion unit 218 converts L ^* C ^* h color system data into L ^* a ^* b ^* color system data. Here, as an example of the conversion method, an LUT (Look Up Table: look-up table) storing a relationship between data of the L ^* C ^* h color system and data of the L ^* a ^* b ^* color system is used.

For example, (a ^* , b ^* ) = (1, 1) ⇔ (C
^* , H ^* ) = (√2, 45 °). At this time, if the LUT stores all combinations of data, the memory capacity becomes enormous. Therefore, only representative data is stored in the LUT, and other data is interpolated (for example, by the nearest neighbor method). Ask.

The second color coordinate conversion unit 219 calculates L ^* a ^* b ^*
This is to convert image data of the color system of the present invention into output image data (CMY in this case) of the second color system. The color coordinate conversion in the second color coordinate conversion unit 219 is performed by the following method. i) Each color patch of C (cyan), M (magenta), and Y (yellow) (output image data of the second color system) is output by the color image forming apparatus. ii) Measure each output color patch with a colorimeter and calculate L ^* a ^* b
^{* Find the} value. iii) The CMY values and the measured L ^* a ^* b ^* values are determined by a neural network or a masking calculation coefficient determination method, and color coordinates conversion is performed using the determined coefficients. When the image output device is a CRT or a liquid crystal display, R,
G, B, are converted. In this case, the conversion is the same as that of the first color coordinate conversion unit 211.

Next, the configuration of the operation panel 220 will be described with reference to the drawings. As shown in FIG. 10, the operation panel 220 includes a distribution information display unit 221, an operation input unit 222, and an area selection unit 223.

The distribution information display section 221 is composed of, for example, a liquid crystal display or the like, and receives input image data (L ^* a ^* b ^*).
The image data of the color system or the image data of the L ^* C ^* h color system is displayed on the a ^* -b ^* plane or the L ^* -C ^* plane.

In the case of displaying on the a ^* -b ^* plane, as shown in FIG. 15, the distributions of a ^* and b ^* for all the L ^* values of the input image data are accumulated and displayed on the distribution information display section 221. a
^* -B ^* Display on the plane 221a. The a ^* -b ^* plane 22
In 1a, the distribution of hue / saturation can be seen. The distribution at the center indicates that there are many dull colors, and the distribution at the outer periphery indicates that there are many vivid colors.

When a plurality of data exist at the same coordinate value, as shown in Table 1, the accumulation status of the data is displayed in detail by changing the color or the symbol (for example, when the distribution information display section is monochrome). You may. For example, when there are 1 to 3 duplicate data, pale yellow or ○
Expressed by

At this time, as shown in FIG. 17, in the distribution information display section 241, a display section 245a for displaying a lightness value as the lightness value (L ^* ) selecting means 245 and the setting button 2
45b may be used to display the distribution of a ^* and b ^* for an arbitrary brightness. Alternatively, the distribution of a ^* and b ^* may be displayed with a range in brightness. Symbol 2 in the figure
42a is an input screen.

When the input image data is displayed on the L ^* -C ^* plane, as shown in FIG. 16, C ^* (C = √ (a ^{* 2} + b ^* ) for all the L ^* values of the input image data ^{. 2} )) The L ^* -C ^* plane 2 on the distribution information display unit 231 is accumulated by accumulating the distribution of ² )).
31a. On the L ^* -C ^* plane 231a, information on brightness and darkness can be found. At this time, the hue value (h = tan ⁻¹ (b ^* ) selected by the display unit for displaying the hue value as the hue value (h) selection means and the setting button ^.
/ A ^* )), the distribution of L ^* and C ^* may be displayed (color is easy to understand). Also in this case, the distribution of L ^* and C ^* may be displayed with a certain hue. Reference numeral 232a in the figure is an input screen.

As another example, as shown in FIG.
A combination of the L ^* -C ^* plane 251a and the input screen 252a on the distribution information display unit 251 may be used. The L ^* -C ^* plane 251a is provided with a display unit 253a as a hue value (h) selection unit 253 at the lower center of the panel and L ^* , C ^* for the h value selected by the setting button 253b ^.
Are cumulatively shown on the screen. In the figure, reference numeral 253c denotes a color display unit for displaying a color, and 252a denotes an input screen. With reference to this distribution plane, it is possible to perform a modification input in the operation input unit 222.

Further, by changing the hue value (h) selecting means 253 in the figure, it is possible to select the hue angle width corresponding to the range of the representative colors red, yellow, green, blue and purple.
This is a modified example corresponding to claim 6.

In the color correction unit 100 according to the first embodiment,
When performing the above-described modification processing, the processing is performed on all images. On the other hand, in the color correction unit 210 according to the second embodiment, the above-described modification processing can be performed on an arbitrary area in an image. Therefore, the color correction unit 210 according to the second embodiment selects an area. That is, the image data input to the distribution information display unit 221 is displayed, and whether or not to perform the color correction is selected. And when you make some modifications,
For example, the following method is used.

First, the image data is displayed on the distribution information display section 221. Here, the input image data after the input gradation correction processing may be stored in a storage means such as an image memory, and the data may be read out and displayed.

Then, from the image data displayed on the distribution information display section, an area is selected by, for example, an image segmentation method disclosed in Japanese Patent Laid-Open No. Hei 6-187442. This area selection processing is performed by the area selection unit 223.

In the area selecting section 223, the processing area is
The image data is divided into a plurality of small regions that allow overlapping, and one or more pixels of a portion to be cut out and unnecessary pixels are designated for each of the small regions, and a color space ( A representative point (a region to be cut out) and a reference point (a point outside the region) in the RGB space) are determined, a line segment connecting the representative point and the reference point is drawn, and the line segment is included in t: (1-t). An identification process is performed using a plane to be divided (when there is a single designated pixel) or a curved surface (when there are a plurality of designated pixels) as an identification plane.

More specifically, the following area selection processing is performed. 1) First, an edge image is created. Here, the absolute value, square, and zero crossing of the first derivative and the second derivative, which are conventional techniques, are used. 2) k parameters t (1), t (2), t (3),
.., T (k) is specified, and cutout is performed using a parameter t (i) having i as a variable. 3) The outline of the region cut out in 2) is taken. 4) A cross-shaped spatial filter 225 as shown in FIG.
Apply to all target small areas. 5) The degree of coincidence between the edge image created in 1) and the contour image created in 3) is calculated using, for example, an absolute value residual sum (Equation 3) or a normalized correlation value (Equation 4), and the identification process is performed. Do.

Next, the processing according to the second embodiment will be described with reference to FIGS.
This will be described with reference to FIG. First, when the image data processing is started, in S1, the image data of the first color system (L ^* a ^* b ^* ) is input from the modification input confirmation unit 212 to the operation panel 220. It is displayed on the distribution information display unit 221. At this time, the image data of the L ^* C ^* h color system converted by the L ^* C ^* h conversion unit is displayed on the operation panel 2.
20, and may be displayed on the distribution information display unit 221.

In S2, the user confirms the display and determines whether or not to perform a modification process on the image data.
An instruction as to whether or not to perform color modification (operation / non-operation) is input from the operation input unit 222.

Next, in S3, the instruction signal is transmitted to the modification input confirming section 212, and when the image modification processing is not performed (in the case of non-operation), a flag is set so that the following color modification processing is omitted. F is set to F = a.

In the case of performing color correction (in the case of operation), it is confirmed in S4 whether or not to select an area.

When the area is selected, in S5, the operation input section 222 instructs the user to select an area. By this selection instruction, the area selection unit 2
Reference numeral 23 determines an area to be subjected to the modification processing, and the area instruction signal is transmitted to the modification input confirmation unit 212, and the following color modification processing is performed only on the selected area. In S4, after No, or after S5, the process proceeds to S6, where the color correction processing is performed.

This color modification will be described in more detail with reference to a flowchart. In the color modification processing, as shown in FIGS. 10 and 12, the modification input confirmation unit 212 confirms whether or not the color modification processing is performed. That is, in S11, it is confirmed whether or not the flag F is set to F = a.

If the color modification processing is not performed, in S20, the L ^* a ^* b ^* system image data is sent to the second color coordinate conversion unit 219, converted into CMY system image data, and It is sent to the processing unit.

If the color modification processing is performed,
And L^*C^*In the h conversion unit 213, L ^*a^*b^*System image day
TA is L^*C^*It is converted to h-series image data. And S1
At 3, L^*C^*/ H in the separation unit 214^*C^*h-series day
Is L^*C^*Data and h data. Further
Then, in S14, the distribution information of the input image data is operated.
It is displayed on the distribution information display section 221 of the panel 220.

This display is performed by using the a ^* -b ^* plane 221a or the L ^* C ^* h conversion unit using the L ^* a ^* b ^* system image data input from the modification input confirmation unit 212 shown in FIG. 2
13 using the L ^* C ^* h system image data input from the L ^*
-C ^* Displayed on plane 222a.

Next, in S15, the user inputs how to color-modify the input image data. This input is performed by the method shown in FIG. Then, in S16, ΔL ^* and ΔC ^* are input from the operation input unit 222 to the difference calculation unit 2.
The brightness L ^* 'and the saturation C ^* ' after color adjustment are obtained by the difference calculation.

Next, in S17, the correction processing unit 216
In L ^* 'C ^*' data and h data and is summarized outputs L ^* C ^* h system image data is obtained. And S1
In step 8, the image data is sent to the distribution information display unit 221 and displayed. The user determines whether or not to end the color modification process based on the display, and inputs an instruction from the operation input unit 222.

This instruction signal is sent to the correction completion confirmation section 217. When redoing color correction, check the completion of correction 2
17 to the L ^* C ^* h conversion unit 213, and the processes in S14 to S18 are repeated.

When the color modification processing is completed, in step S19, the L ^* a ^* b ^* conversion unit 218 converts the L ^* C ^* h system image data into L ^* a ^* b ^* system image data.
In S20, the second color coordinate conversion unit 219 outputs L
^The image data of ^* a ^* b ^* system is converted into image data of the second color system (CMY system) and output to the subsequent processing unit.

[0119]

As described above, the first aspect of the present invention is as described above.
According to the image processing apparatus and the image forming apparatus including the same, when performing color retouching of a color image, the distribution information display means for displaying a distribution state of the color image data is used to display the color image data. By displaying the distribution state on the lightness-chroma plane or the a ^* -b ^* plane, it is possible to grasp the overall distribution state of the color image data, and according to the state, for example, a certain hue Since detailed conditions can be set, such as applying color correction only to a specific range that is biased, the output result can be easily guessed, and an excellent effect that an image more preferred by the user can be obtained can be obtained.

Further, according to the present invention, the color correction means performs the color correction processing based on the distribution information of the distribution information display means for displaying the distribution information of the color image data of the first color system. The color correction can be performed on an arbitrary area selected by an area selecting unit that selects an arbitrary area of the color image data having the first color system.
Since color correction is performed by calculating the difference between the brightness difference and the saturation difference,
An excellent effect is obtained that the processing can be easily performed and the circuit configuration is also simplified. Further, by providing the image processing apparatus described above in the image forming apparatus, it is possible to provide an image forming apparatus capable of performing color correction of an arbitrary area by a simple color correction method.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an example of a configuration of a digital color copying machine including a color image processing apparatus to which a color image processing method and a color image processing apparatus according to an embodiment of the present invention are applied.

FIG. 2 is a block diagram of a color correction unit and an operation panel of the image processing apparatus according to the first embodiment of the present invention.

FIG. 3 is a flowchart illustrating an image data processing procedure of a color correction unit illustrated in FIG. 2;

FIG. 4 is an explanatory diagram showing an example of an input screen of a color modification condition displayed on the operation input unit shown in FIG. 2;

5 is an explanatory diagram showing an example of a color tone diagram representing lightness difference (ΔL ^* )-saturation difference (ΔC ^* ) displayed on the distribution information display section shown in FIG. 2;

FIG. 6 is an explanatory diagram showing an example of an input screen for inputting distribution information and correction processing conditions of an a ^* -b ^* plane (all L ^* values) of input image data displayed on the distribution information display unit.

FIG. 7 is an explanatory diagram showing an example of an input screen for inputting distribution information and correction processing conditions on an L ^* -C ^* plane (all h values) of input image data displayed on the distribution information display unit.

FIG. 8 is an explanatory diagram showing an example of an input screen for inputting distribution information of an a ^* -b ^* plane (all L ^* values) and correction processing conditions of input image data displayed on the distribution information display unit.

FIG. 9 is an explanatory diagram showing an example of an input screen for inputting distribution information and correction processing conditions on an L ^* -C ^* plane (all h values) of input image data displayed on the distribution information display unit.

FIG. 10 is a block diagram illustrating a configuration of a color correction unit and an operation panel of an image processing apparatus according to a second embodiment of the present invention.

11 is a flowchart illustrating an image data processing procedure of the color correction unit illustrated in FIG. 10;

FIG. 12 is a flowchart illustrating a color correction processing procedure of the flowchart illustrated in FIG. 11;

FIG. 13 is an explanatory diagram illustrating an example of an input screen of a color modification condition displayed on the operation input unit of the image forming apparatus.

14 is an explanatory diagram showing an example of a color tone diagram representing lightness difference (ΔL ^* )-saturation difference (ΔC ^* ) displayed on the distribution information display section shown in FIG.

FIG. 15 is an explanatory diagram showing an example of an input screen for inputting distribution information of the a ^* -b ^* plane (all L ^* values) and correction processing conditions of input image data displayed on the distribution information display unit.

FIG. 16 is an explanatory view showing an example of an input screen for inputting distribution information and correction processing conditions of an L ^* -C ^* plane (all h values) of input image data displayed on the distribution information display unit.

FIG. 17 is an explanatory diagram showing an example of an input screen for inputting distribution information on the a ^* -b ^* plane (all L ^* values) and correction processing conditions of input image data displayed on the distribution information display unit.

FIG. 18 is an explanatory diagram showing an example of an input screen for inputting distribution information and correction processing conditions on the L ^* -C ^* plane (all h values) of input image data displayed on the distribution information display unit.

FIG. 19 is a diagram for describing a spatial filter process used in a process for identifying a region in a method for selecting a region used in the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Image processing apparatus 2 Color image input apparatus 3 Color image output apparatus 4 Digital color copying machine 14, 100, 210 Color correction part 104, 114, 124, 134, 144, 154, 2
22 Operation input unit 104a Display unit 110, 221, 231, 241, 251 Distribution information display unit 111 Color coordinate operation unit 120, 130, 140, 150 Panel 121, 141, 221a a ^* -b ^* plane 131, 151, 231a, 251a L ^* -C ^* plane 145, 245 Brightness value (L ^* ) selection means 155, 253 Hue value (h) selection means 160, 220 Operation panel 216 Correction processing unit 222a, 232a, 242a, 252a Input screen 223 Area selection unit 225 Cross-shaped spatial filter

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C262 AA24 AA26 AB11 AC08 BA03 BA16 BA19 EA02 EA04 FA14 GA23 5B057 AA11 CA01 CA08 CA12 CA16 CB01 CB08 CB12 CB16 CC01 CE17 CE18 5C077 LL16 LL17 LL19 MP08 PP31 PP32 PP33 PP35 PP33 PP35 PQ15 SS01 SS05 SS06 TT04 TT05 TT06 TT09 5C079 HB01 HB03 HB06 HB08 HB11 LA10 LA31 LB02 MA11 MA17 NA03 NA09 NA27 PA02 PA03

Claims (15)

[Claims] 1. An image processing apparatus comprising: a color correction unit configured to convert color image data having a first color system into color image data having a second color system. An image processing apparatus comprising: a color adjustment unit that performs color adjustment based on distribution information of a distribution information display unit that displays distribution information of color image data composed of a color system. 2. The image processing apparatus according to claim 1, wherein the color correction unit performs color correction on an area selected by an area selection unit that selects an arbitrary area of the color image data having the first color system. Item 2. The image processing device according to Item 1. Wherein the color adjustment unit, said distribution is displayed on the information display means, the distribution of a ^* -b ^* plane based on the chromaticity a ^* · b ^* of the color image data consisting of the first color system 3. A color correction process according to information.
An image processing apparatus according to claim 1. 4. The color retouching means performs a color retouching process based on distribution information of a brightness-chroma plane of color image data of a first color system displayed on the distribution information display means. The image processing apparatus according to claim 1 or 2, wherein 5. The color modifying means according to the distribution information of a lightness-saturation plane and a ^* -b ^* plane of color image data of a first color system displayed on the distribution information display means. The image processing apparatus according to claim 1, wherein a modification process is performed. 6. The color modifying unit divides a brightness-chroma plane (space) of color image data of a first color system displayed on the distribution information display unit into a plurality of color direction ranges. The image processing apparatus according to claim 4, wherein a color correction process is performed based on distribution information of a lightness-chroma plane in a range of a selected color direction from the selected ones. 7. The color modifying means selects a lightness-saturation plane (space) of color image data of a first color system displayed on the distribution information display means, the color being selected by a hue angle h. The image processing apparatus according to claim 4, wherein the color correction processing is performed based on distribution information of a lightness-saturation plane in a direction range. 8. The color correcting means according to distribution information of arbitrary plural a ^* -b ^* planes of color image data of a first color system displayed on the distribution information display means. The image processing apparatus according to claim 3, wherein: 9. The color modifying means according to the distribution information on the a ^* -b ^* plane at an arbitrary lightness value of the color image data of the first color system displayed on the distribution information display means. The image processing apparatus according to claim 3, wherein the processing is performed. 10. The color modifying means according to claim 1, wherein said color modifying means includes a color image data of a first color system, said color image data being displayed on said distribution information display means, in an a ^* -b ^* plane of a range divided by an arbitrary lightness value. The image processing apparatus according to claim 3, wherein a color modification process is performed based on the distribution information. 11. The color retouching means executes color retouching processing based on distribution information of a plurality of arbitrary lightness-saturation planes of color image data of a first color system displayed on the distribution information display means. The image processing apparatus according to claim 4, wherein the image processing is performed. 12. The color modifying means is input based on distribution information on a brightness difference-saturation difference plane of color image data of a first color system displayed on the distribution information display means. The image processing apparatus according to claim 1, further comprising a calculation unit that performs a color correction process based on the difference data. 13. The arithmetic unit according to claim 1, wherein the arithmetic unit performs a color adjustment operation on all of the first color system based on coordinates on a brightness difference-chroma difference plane of the color image data formed by the first color system. 13. The image processing apparatus according to claim 12, wherein the processing is performed over color image data. 14. An arithmetic unit for color correction based on coordinates on a brightness difference-saturation difference plane of color image data of a first color system based on coordinates of a selected brightness / hue range. 13. The image processing apparatus according to claim 12, wherein the processing is performed on color image data having a first color system. 15. An image forming apparatus comprising the image processing apparatus according to claim 1. Description: