JP2002118763A - Color image output method and color image output device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color image output method that can execute calibration of the color reproducibility, in response to the characteristics of an image outputted from a color image output device with high accuracy, without requiring time and labor. SOLUTION: The color image output method, that can calibrate the color reproducibility in matching with the characteristic of an output of the color image forming device of this invention, is configured such that the color distribution of input image data is analyzed (S2), RGB data are converted into cmyk density data through color conversion, on the basis of the characteristic of the color image forming device according to a gradation with high frequency of incidence (S3), a reference color chart for calibration expressing the characteristics is generated (S7), the color of the outputted reference color chart is measured to receive data c'm'y'k' corresponding to the density data cmyk (S8), the density data cmyk data, a CMYK-cmyk correction table prior to the calibration and the density data c'm'y'k' are compared, and update the CMYK-cmyk correction table is updated and to calibrate the color.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a color image output method capable of calibrating color reproducibility in accordance with the characteristics of a color image output device such as a color printer.

[0002]

2. Description of the Related Art Conventionally, differences in color and density of hard copy (output to paper) due to differences in output conditions such as individual differences of color image output devices such as color printers, environmental changes, and changes over time have been known. In order to eliminate the problem, many techniques for calibrating the color reproducibility of a printer or the like in advance have been provided. For example, as a calibration technique for a color printer alone, a reference chart is output and measured with a spectrophotometer, or a reference chart prepared in advance is compared with human eyes. There is a technique for calculating calibration data. For example,
In the color image output device described in Japanese Patent Application Laid-Open No. 6-350838, the density of each of CMY (the basic colors of cyan, magenta, and yellow printers) for each of the RGB (the three primary colors of red, green, and blue light). Is changed to output a plurality of samples of the standard setting value, and an appropriate color is selected from the samples of the standard setting value and input, thereby performing color tone correction from RGB to CMY. Further, Japanese Patent Application Laid-Open No.
In the calibration adjustment method for a color printer disclosed in Japanese Patent Application Publication No. 562, the adjustment is performed for each of CMYK of the color printer in the case of highlight, middle, and shadow using a reference chart, and the other portions are calculated by interpolation. Approximate and generate gamma correction data. Further, as a conventional technique for matching colors displayed on a monitor with colors output on paper by an image output device (printer), there is, for example, Software Color Sync provided by Apple Inc. In this conventional technique, a profile representing the characteristics of each of a monitor and an image output device, that is, a file in which the characteristics are described, is used to obtain the same image quality level as the image displayed on the monitor regardless of the model of the image output device. Can be printed. Also,
The prior art disclosed in Japanese Patent Application Laid-Open No. 10-145626 satisfactorily reproduces the brightness, saturation, and hue of a portion of the image to which a person pays attention, such as a memory color, and the gradation characteristics and hue of the entire image. The purpose of the present invention is to ensure linearity and prevent collapse of high-saturation portions. Pixel image data of each of red, green, and blue color components (hereinafter, referred to as RGB image data) dependent on the image input device is independent of the image input device. L * a * b *
The data is converted into data (data expressed in L * a * b * color space coordinates), and further converted into data corresponding to the characteristics of the image output device, thereby converting a plurality of characteristic colors in the RGB image data into a predetermined color. And the conversion is performed so as to maintain the linearity of the color reproduction characteristics of the output image. In the above description, the characteristic color in the input image data means a memory color, which is stored as color space data independent of the image input device. For example, characteristic colors are human skin color, blue sky, green trees, and the like. The color of the predetermined range A in the RGB image data is human skin color, the color of the predetermined range B is the sky color, and the color of the predetermined range C is trees. Are converted into predetermined color space data stored independently of the image input device. Also,
In accordance with this conversion tendency, RGB image data other than the characteristic color is also converted.
The B image data is converted into image data independent of the image input device.

[0003]

However, in the above-mentioned prior art, in order to improve the accuracy of calibration in all color gamuts, a large number of reference charts are output and the reference charts are output. After performing colorimetry with a reference chart or comparing a reference chart prepared in advance with the human eye, make settings using the multiple regression full model method (a method in which correction result errors are fed back to parameters), and calibration is performed. If the number of reference charts is reduced, the other parts will be approximated by interpolation, and the color gamut with non-linear characteristics will have to be calculated. Error occurs, and when an image containing a large amount of the color gamut is output, color differences and density differences may cause problems, and sufficient calibration (calibration) accuracy is required. There is a problem that can not be obtained. In addition, particularly in image formation by an electrophotographic method,
There is also a density difference depending on the position where the image is formed, and even if the calibration is performed with high accuracy, the position where the reference chart of a certain color is formed and the position when the image is actually formed (the color is formed) If the positions are far apart, there is a problem that a color difference or a density difference occurs. An object of the present invention is to solve such a problem of the related art, and perform calibration of color reproducibility (calibration) according to characteristics of an image output by a color image output device without requiring time and labor. Another object of the present invention is to provide a color image output method that can be performed with high accuracy.

[0004]

According to the first aspect of the present invention, there is provided a color image forming apparatus capable of calibrating color reproducibility in accordance with output characteristics of a color image forming apparatus. In the output method, a color distribution of the input image data to be output is detected, a calibration image formed according to the detected color distribution is output using a color image forming apparatus, and an output color characteristic of the output calibration image is output. The correction data is calibrated by using the function. According to a second aspect of the present invention, in the first aspect, a reference color chart having a color arrangement according to the color distribution of the input image data is output as a calibration image. According to a third aspect of the present invention, in the second aspect of the present invention, a color arrangement is formed by extracting image data having a high appearance frequency from individual image data appearing in the input image data.
According to a fourth aspect of the present invention, in the second or third aspect, the reference color patch is output in an expression that clarifies the input image area corresponding to the reference color patch. According to a fifth aspect of the present invention, in the second or third aspect, one reference color patch corresponding to a partial area of the input image is generated, and the reference color patch is generated by the color image forming apparatus. The image is output to a plurality of image forming positions. According to a sixth aspect of the present invention, in the second or third aspect, a predetermined specific color is preferentially added to the color arrangement of the reference color chart. According to the seventh aspect of the present invention, in the second aspect or the third aspect,
In the described invention, the color distribution of the input image data in the designated image area or the color distribution of the designated specific input image data is reflected on the reference color chart. In the color image output apparatus according to the present invention, the color reproducibility can be calibrated in accordance with the output characteristics of the color image forming apparatus. A detecting means, a reference color chart generating means for generating a reference color chart for calibration having a color configuration according to the color distribution detected by the characteristic detecting means, and a color image forming apparatus using the generated reference color chart. And a calibration means for calibrating the correction data using the output color characteristics of the outputted reference color chart. According to a ninth aspect of the present invention, a program programmed according to the color image output method according to the first to seventh aspects is stored in a storage medium storing the program.

[0005]

According to the first aspect of the present invention, the color distribution of the input image data to be output is detected, and the calibration image formed according to the detected color distribution is output to the color image forming apparatus. And the correction data is calibrated using the output color characteristics of the outputted image for calibration. According to a second aspect of the present invention, in the first aspect, a reference color chart having a color arrangement according to the color distribution of the input image data is output as a calibration image. According to a third aspect of the present invention, in the second aspect of the present invention, the color arrangement is configured by extracting image data having a high appearance frequency from individual image data appearing in the input image data. According to the fourth aspect of the present invention, in the second or third aspect of the present invention, the input image area corresponding to the reference color patch becomes apparent from the output reference color patch. According to a fifth aspect of the present invention, in the second or third aspect, one reference color patch corresponding to a partial area of the input image is generated, and the reference color patch is generated by a plurality of reference color patches of the color image forming apparatus. Output to the image forming position. According to a sixth aspect of the present invention, in the second or third aspect of the present invention, the specific color set in advance is preferentially added to the color configuration of the reference color chart. In the invention according to claim 7, in the invention according to claim 2 or 3, the color distribution of the input image data in the specified image area or the color distribution of the specified specific input image data is included in the reference color chart. Will be reflected. According to the present invention, the color distribution of the input image data to be output is detected, a calibration reference color chart having a color configuration according to the detected color distribution is generated, and the generated reference color chart is color-coded. The correction data is output using the image forming apparatus, and the correction data is calibrated using the output color characteristics of the output reference color chip. According to the ninth aspect of the present invention, a program programmed according to the color image output method of the first to seventh aspects is stored in, for example, a removable storage medium.

[0006]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a configuration block diagram of an image processing system according to an embodiment of the present invention. As shown, the image processing system of this embodiment includes a color image output processing device 1, a computer 2 that passes and controls image data to the color image output processing device 1, and an output of the color image output processing device 1. A color image forming apparatus (for example, a color printer or a color copying machine) 3 for printing a color image on paper according to print data to be printed is provided. When the computer 2 receives an output instruction and a color calibration (calibration) instruction input by the user using the operation unit, the computer 2 is usually loaded from a camera or the like or created by various DTP (document publishing) software or the like. In addition, image data of a composite document including a monochrome or color photograph, graphic, text, and the like are transferred to the color image output processing device 1. The color image output processing apparatus 1 analyzes input image data obtained from the computer 2 in accordance with a command from the computer 2 only when a user gives a color calibration instruction, and performs color proofing processing and color The output color component C which is a control signal passed to the color image forming apparatus 3 by the conversion process
(Cyan), M (Mazenta), Y (Yellow), K (black)
The signal is converted into a signal, and the result is transferred to the color image forming apparatus 3. Then, the color image forming apparatus 3 prints out (prints) according to the transferred control signal.

The color image output processing device 1 may be mounted inside the color image forming device 3 or the like, or may be mounted inside the computer 2. Further, it may be mounted independently of the color image forming apparatus 3. Further, the color image output method of the present invention can be realized by a program (software), and in that case, it can also be realized by a printer driver existing as a program in a computer. Further, as shown in FIG. 1, the color image output processing apparatus 1 of this embodiment generates print image data (image data) in accordance with a drawing command from a computer 2 described in a page description language (PDL) or the like. Unit 11 for receiving image data (RGB) from computer 2 and an image for temporarily storing input image data (color image data) including print image data drawn (generated) by drawing unit 11 A storage unit (storage buffer) 12, an input image characteristic detection unit 13 for detecting a color distribution of the stored input image data, and a control signal (cmy) for input image data (RGB) for a color image forming apparatus.
k), a color calibration unit 15 for calibrating color reproducibility in the color image forming apparatus 3, a gamma correction unit 16 for gamma correction, and detection by the input image characteristic detection unit 13. A reference color chart generation unit 17 for generating a reference color chart for calibration in accordance with the color distribution of the input image data, a halftone processing unit 18 for performing halftone processing, and the like. In this embodiment, the characteristic detecting means described in claim 8 is realized by the input image characteristic detecting unit 13.
The reference color chart generation unit is realized by the reference color chart generation unit 17, the reference color patch output unit is realized by the color conversion unit 14, the gamma correction unit 16, and the like, and the calibration unit is realized by the color calibration unit 15. The color image output processing device 1
Are the gradation data of RGB (red, green, blue), and the gradation number of each color component is 256 gradations (8 gradations).
bit) is common, but another number of gradations such as 64 gradations or 512 gradations may be used.

Next, the operation of the color image output processing 1 will be described. First, the drawing unit 11 outputs the page description language (P
DL) for generating image data in accordance with a drawing command from the computer 2,
The input image data obtained by receiving image data (RGB) from the image storage unit 12 is temporarily stored in the image storage unit 12. Then, the input image characteristic detection unit 13 analyzes the color distribution of the input image data stored in the image storage unit 12 only when receiving both the output instruction and the color calibration instruction from the user. The image data is sent to the conversion unit 14. The color conversion unit 14 performs color conversion based on the characteristics of the color image forming apparatus (for example, a color printer) 3 to output color components c (Cyan) and m (Mazent) of the color image forming apparatus 3.
a), y (Yellow) and k (black) are converted into, for example, density data. The color conversion in the color conversion unit 14 uses, for example, a memory map interpolation method. Specifically, as shown in FIG. 2, when an RGB space having R, G, and B data component values as respective coordinate axes is used as an input color space, the RGB space is converted into a solid figure of the same type (here, a cube). Output values (c, m, and m) corresponding to input coordinate values (RGB component values) P
To obtain y, k), a cube including the input coordinate value P is selected, the output values of eight preset vertices of the selected cube and the position of the input coordinate value P in the cube are set. (The distance from each vertex, and this value may be obtained by the input image characteristic detecting unit 13 in association with each loci) by linear interpolation. Here, in the case of this embodiment, the output value corresponding to P is c,
Output values (c, m, y, k) corresponding to the density values of m, y, and k and corresponding to the coordinate values (RGB) of the vertices in the input space used for the interpolation operation are calculated based on the actual input / output ( RGB (= L * a * b *) calculated by measuring the relationship between colorimetric values such as L * a * b * and CMYK) and using this data by the least square method or the like
, And is set in advance as an RGB-CMYK conversion table associated with each vertex. The color conversion unit 14 uses such a conversion table to generate c
The image data converted to the myk density value is converted to a gamma correction unit 16.
The gamma correction unit 16 obtains CMY, which is a control signal of the color image forming apparatus (for example, a color printer) 3.
The data is converted into K data (8 bits), and a reference color chart generation unit 17 generates a reference color chart (details will be described later) corresponding to the color distribution of input image data output to the color image forming apparatus 3 for calibration. Then, the halftone processing unit 18 performs halftone processing (binary dither, multi-value dither, error diffusion, etc.) for the color image forming apparatus 3 according to the selected print quality, and sends it to the color image forming apparatus 3. Send and output the reference color chart for calibration. Then, the user measures the calibration reference color chip output by the color image forming apparatus 3 with a spectrophotometer and obtains the measured value using the computer 2 or compares the measured value visually with a reference chart prepared in advance. The colorimetric density data c'm ', which is the output color characteristic of the output reference color chip, corresponding to the density data cmyk obtained by performing the color conversion in the color conversion unit 14 y'k 'is input using the computer 2. Thereby, the color proofing unit 1
5 obtains the input data c'm'y'k '.

In the color proofing section 15, density data cmyk obtained by performing color conversion in the color conversion section 14 on the image data of the calibration reference color chart generated in the reference color chart generation section 17.
And CMYK-cmy before calibration in the gamma correction unit 16
The CMYK-cmyk correction table is updated by comparing the k correction table (see FIG. 3) with the colorimetric density data c'm'y'k 'of the reference color chip input via the computer 2. At this time, data other than the data corresponding to the calibration reference color chart is corrected (updated) by linear or spline interpolation, and the color calibration (calibration) is completed. When this color proofing (calibration) is completed,
After the image output is resumed and the input image data temporarily stored in the image storage unit 12 is color-converted into cmyk density data by the color conversion unit 14 using the RGB-CMYK conversion table as described above, The gamma correction unit 16 performs gamma correction (CMYK → c) using the CMYK-cmyk correction table calibrated (calibrated) by the calibration unit 15.
myk), the halftone processing unit 18 performs halftone processing (binary dither, multilevel dither, error diffusion, etc.) for the color image forming apparatus 3 according to the selected print quality, and 3 and the image output is completed. When there is no color calibration command from the computer 2, the processing in the input image characteristic detecting unit 13, the reference color chart generating unit 17, and the color correcting unit 15 is not performed, and
The image output processing is performed as it is. Next, the processing in the reference color chart generator 17 and the like when a color calibration command is issued will be described in detail with reference to FIG.
First, input image data (RGB) stored in the image storage unit 12
The input image characteristic detection unit 13 detects a color distribution (RGB) for each image forming area (for example, for each position of one document). For example, a color (RGB) existing at a predetermined frequency or more is detected for each of the nine target regions obtained by dividing the entire image forming area into three equal parts in the vertical and horizontal directions, or a color existing at a predetermined frequency or more in the user-specified area as shown in FIG. Detect color. Then, the color conversion unit 14
And the gamma correction unit 16 determines whether the detected color
The color conversion into YK data is performed, and the reference color chart generation unit 17 selects a plurality of (for example, 32) data values (gradation values) in descending order of appearance frequency for each area, and arranges the plurality of data values (grayscale values) for each CMYK ( A plurality of, for example, 32 pieces may be arranged in any order), and the halftone processing section 18 is used for the color image forming apparatus 3 according to the selected print quality. (Two-valued dither, multi-valued dither, error diffusion, etc.) are sent to the color image forming apparatus 3, and the output of the calibration reference color chart is completed. That is, a reference color chart having a color scheme showing the color characteristics of the input image data is output, and as an output format, for example, a plurality of gradation values can be obtained without using an area by forming a band as shown in FIG. It can output and measure color efficiently.

When the input image characteristic detecting section 13 detects a specific color which has been set in advance (set within a specified range of hue, saturation and lightness), for example, flesh color or sky, the number of pixels (frequency of appearance) ), The image data of the particular color is sent to the reference color chart generator 17 and the like in order to generate the reference color chart of the specific color in addition to the plurality of data values to be selected. When a user specifies an image of a specific object such as an image area or “sky” via the computer 2, the input image characteristic detection unit 13 detects an input image characteristic of the specified area or the target object. The reference color chart generation unit 17 generates and outputs a reference color chart chart according to the input image characteristics. At this time, a reference color chart chart is formed at an image forming position corresponding to the area where the color is used in the input image, so that the input image area corresponding to the reference color chart is clearly (expressed expression).
May be. Further, a configuration in which a reference color patch corresponding to a partial area in an input image is output to a plurality of image forming positions is also possible. With such a configuration, a difference in characteristics depending on the image forming position of the image forming apparatus can be reflected in the configuration data. For example, colorimetry is performed on a plurality of output reference color chips, and the average value is fed back, and c ′, m ′, y ′,
k '. Thus, according to the color image output processing apparatus 1 of this embodiment, the color reproducibility calibration (calibration) according to the characteristics of the image output from the target color image forming apparatus 3 at that time is performed by the CMYK-cmyk correction table. Can be performed with high accuracy without requiring time and labor.

FIG. 5 shows an operation flow for explaining a color image output method performed by the color image output processing apparatus 1 described above. Hereinafter, the operation of the color image output method of this embodiment will be described with reference to FIG. First, the input image characteristic detection unit 13 determines whether or not there is a color calibration instruction from the user (S1), and stores it in the image storage unit 12 only when there is an instruction (Yes in S1). The color distribution (such as the frequency of appearance for each area) of the input image data is analyzed to prepare image data (color patch data) for the reference color patch (S2). Then, the color conversion unit 14 performs an output color component c (Cyan), m (Mazenta), y by color conversion based on the characteristics of the color image forming apparatus (for example, a color printer) 3 from the RGB data by the memory map interpolation method. (Yel
low) and k (black), for example, to density data (S
3). Subsequently, the gamma correction unit 16 acquires the image data converted to the cmyk density value, and controls the color image forming apparatus 3 as a control signal C according to the current (before calibration) characteristics.
MYK (8 bits) is converted (S4), and the reference color chart generation unit 1
7 generates the above-described reference color chart chart corresponding to the input image characteristic output for calibration (S5), and the halftone processing unit 18 performs the halftone processing for the color image forming apparatus according to the print quality ( Binary dither, multi-value dither, error diffusion, etc.) are performed (S6), and the color image forming apparatus 3 outputs a reference color chart (S7). Next, the user performs color conversion on the output calibration reference color chart with a spectrophotometer or visually compares a reference chart prepared in advance to obtain the number of the closest one. Data corresponding to the density data cmyk obtained by performing the color conversion in the unit 14 is input (S8). Thus, the density data cmyk output as the reference color chart data for calibration and the CMYK-cmy before calibration are obtained.
The CMYK-cmyk correction table is updated by comparing the k correction table (see FIG. 3) with the colorimetric density data c'm'y'k 'of the reference color chip input in step S8 (S
9), end the color calibration. Subsequently, in step S10, the image output is restarted, the color conversion unit 14 temporarily converts the input image data stored in the image storage unit 12 into cmyk density data (S10), and the gamma correction unit 16 performs calibration. (Calibrated) CM
Gamma correction is performed using the YK-cmyk correction table (S11), the halftone processing unit 18 performs halftone processing (S12), and the color image forming apparatus 3 outputs an image. On the other hand, if it is determined that the color calibration is not performed in step S1 (No in S1), steps S2 to S9 are skipped and step S9 is performed.
Proceed to 10.

FIG. 6 shows a hardware configuration of a workstation that covers the image output processing device 1 and the computer 2, and the like. The image processing system shown in FIG. 6 connects a printer 21 as a color image forming apparatus 3, a digital still camera 22 as an image input apparatus, and a scanner 23 around a work station 20,
The workstation 20 includes a display device 31, a keyboard 32, a program reading device 33, an arithmetic processing device 34, and the like. In addition, the arithmetic processing unit 34 includes a CPU 41 for executing various processes according to a program,
It includes an OM 42, a RAM 43, a hard disk device 44 as a large-capacity storage device, a network control device (NIC) 45 for communicating with other information devices on a network, and the like. The program reading device 33 is a storage medium storing various programs, that is, a floppy disk, a hard disk, an optical disk (CD-ROM, CD-R, CD
−R / W, DVD-ROM, DVD-RAM, etc.), a magneto-optical disk, a memory card, etc., for reading a program, such as a floppy disk device (drive), an optical disk device, and a magneto-optical disk device. The program stored in the storage medium is read by the program reading device 33 and stored in the hard disk device 44 or the like. By executing the program stored in the hard disk device 44 or the like by the CPU 41, the above-described color image output method is performed. Can be realized. The program includes an OS running on the workstation 20.
(Operating system) and device drivers. In the above description, the reference color chart as shown in FIG. 4 is output for calibration. However, instead of the reference color chart, for example, a plurality of gradations selected for each of C, M, Y, and K are selected. An image composed of a plurality of circles corresponding to the values may be output. Further, a program programmed in accordance with the color image output method as described above is stored in a removable storage medium, and the storage medium is processed by an information processing apparatus such as a personal computer or a workstation which could not output a color image according to the present invention. By mounting the image processing apparatus on a device, a color image output according to the present invention can be performed in the information processing device.

[0013]

As described above, according to the present invention,
According to the first aspect of the present invention, a color distribution of input image data to be output is detected, and a calibration image formed according to the detected color distribution is output using a color image forming apparatus.
Since the correction data is calibrated using the output color characteristics of the output calibration image, for example, it is possible to automatically measure the output color characteristics and input the correction data, and therefore, the color image output device Calibration of color reproducibility according to the characteristics of the image output by the method can be performed with high accuracy without requiring time and labor. According to the second aspect of the present invention, in the first aspect of the present invention, a reference color chart having a color configuration according to the color distribution of the input image data is output as a calibration image. By forming a belt shape, a plurality of tone values can be output without requiring an area, and a plurality of tone values can be continuously and efficiently measured. According to the third aspect of the present invention, in the second aspect of the invention, the color arrangement is configured by extracting image data having a high appearance frequency from each image data appearing in the input image data. Thus, the reference color chart generation processing is simplified by the decrease in the tone values shown in the reference color chart, and the color distribution of the input image data is correctly reflected even when the tone values shown are reduced. Further, in the invention according to claim 4, in the invention according to claim 2 or claim 3, the input image area corresponding to the reference color patch becomes apparent from the output reference color patch, so that the color of the input image is The correspondence with the distribution becomes easy to understand.

Further, according to the invention described in claim 5, according to claim 2,
In the invention according to claim 3, one reference color patch corresponding to a partial area of the input image is generated and the reference color patch is output to a plurality of image forming positions of the color image forming apparatus. The difference in output color characteristics depending on the position can be reflected in the calibration of color reproducibility. Also, in the invention according to claim 6, in the invention according to claim 2 or 3, the preset specific color is preferentially added to the color configuration of the reference color chart, so that the sky, skin color, etc. Color reproducibility can be improved. According to a seventh aspect of the present invention, in the second or third aspect, the color distribution of the input image data in the specified image area or the color distribution of the specific input image data specified is the reference color. Since this is reflected on the vote, the color reproducibility of the input image of the part of interest can be improved. Further, in the invention according to claim 8, the color distribution of the input image data to be output is detected, and a reference color chart for calibration having a color configuration according to the detected color distribution is generated.
Since the generated reference color patch is output using the color image forming apparatus, and the correction data is calibrated using the output color characteristics of the output reference color patch, the same effect as the invention according to claim 2 is obtained. Obtainable. According to the ninth aspect of the present invention, the program programmed according to the color image output method according to the first to seventh aspects is stored in, for example, a removable storage medium. The present invention is also applied to an information processing apparatus such as a personal computer or a workstation which cannot output a color image according to the present invention.
The effects of the described invention can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of an image processing system according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a color image output method according to an embodiment of the present invention.

FIG. 3 is a data configuration diagram of a main part of a color image output processing apparatus according to an embodiment of the present invention.

FIG. 4 is another explanatory diagram illustrating a color image output method according to an embodiment of the present invention.

FIG. 5 is an operation flowchart of a color image output method according to an embodiment of the present invention.

FIG. 6 is a hardware configuration diagram of an image processing system according to an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 color image output processing device 2 computer 3 color image forming device 11 drawing unit 12 image storage unit 13 input image characteristic detection unit 14 color conversion unit 15 color calibration unit 16 gamma correction unit 17 reference color chart generation unit 18 halftone processing unit 20 Workstation 21 printer 34 arithmetic processing unit

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) G06F 3/12 B41J 3/00 A 5C079 G06T 1/00 510 B H04N 1/46 H04N 1/46 Z F term (Reference) 2C061 AP04 AR01 KK25 KK32. PQ12 PQ20 PQ23 TT02 5C079 HB01 HB03 HB08 HB11 LA02 LB02 MA04 MA10 MA11 NA03 NA13 NA29 PA03

Claims (9)

[Claims] 1. A color image output method capable of calibrating color reproducibility in accordance with output characteristics of a color image forming apparatus, wherein a color distribution of input image data to be output is detected, and the color distribution is detected in accordance with the detected color distribution. A color image output method comprising: outputting a constructed calibration image using a color image forming apparatus; and performing calibration of correction data using output color characteristics of the outputted calibration image. 2. A color image output method according to claim 1, wherein a reference color chart having a color arrangement according to the color distribution of the input image data is output as an image for calibration. 3. A color image output method according to claim 2, wherein a color arrangement is formed by extracting image data of a tone value having a high appearance frequency from individual image data appearing in the input image data. Color image output method. 4. A color image output method according to claim 2, wherein the reference color patch is output in an expression that clarifies a corresponding input image area of the reference color patch. output method. 5. A color image output method according to claim 2, wherein one reference color patch corresponding to a partial area of the input image is generated, and said reference color patch is generated by a plurality of color image forming apparatuses. A color image output method comprising outputting to an image forming position. 6. The color image output method according to claim 2, wherein a predetermined specific color is preferentially added to a color configuration of a reference color chart. 7. A color image output method according to claim 2, wherein a color distribution of input image data in a specified image area or a color distribution of specified specific input image data is used as a reference color chart. A color image output method characterized by reflecting. 8. A color image output apparatus capable of calibrating color reproducibility in accordance with output characteristics of a color image forming apparatus, wherein: a characteristic detection unit for detecting a color distribution of input image data to be output; Reference color chart generation means for generating a reference color chart for calibration having a color configuration according to the color distribution detected by the characteristic detection means, and a reference color for outputting the generated reference color chart using a color image forming apparatus A color image output apparatus comprising: a vote output means; and a calibration means for calibrating correction data using output color characteristics of an output reference color chart. 9. A storage medium storing a program, the storage medium storing a program programmed according to the color image output method according to claim 1. Description: