JP2001045313A - Method and device for converting color, color conversion program storage medium and method for correcting color - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a proof image highly matching the color while suppressing the increase of a memory capacity by converting image data defined in a first color space into image data defined in the second color space by using a printer profile and a correction profile. SOLUTION: A printing profile, which is adapted to information inputted from a printing profile designating part 504, is read from plural printing profiles 501a, 501b,... 501x stored in a printing profile storage part 501 based on the information and is inputted to a color converting part 506. In the meantime, the printer profile designated by the information is read from a printer profile storage part 502 based on information from a printer profile designating part 505 and is inputted to the color converting part 506. Then image data defined in the first color space is converted into image data defined in the second color space by using of the correction profile.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for outputting a proof image reproducing a color of a color print using a printer when performing color printing by a color printing machine. Color conversion method and color conversion device for performing color conversion matched to the color of
A color conversion program storage medium loaded with a computer system and storing a color conversion program for operating the computer system as a color conversion device, and color correction for bringing the color of the proof image closer to the color of a color print About the method.

[0002]

2. Description of the Related Art Conventionally, when printing a color image using a color printing machine, before printing, a color printer or the like is used to make the color of the image printed by the printing machine as same as possible. Creating a similar proof image has been performed. When creating a proof image with a printer, the type of printing machine that is to be printed and the conditions of use of the printing machine (type of ink used, paper quality of printed paper, etc .; type of printing machine) And a print profile describing the relationship between the image data and the actual color of the printed matter, which corresponds to the condition necessary for one type of printing, and the type of printer and its printer. And a printer profile describing the relationship between the image data and the colors of the image actually printed and output, corresponding to the use conditions and the like (these conditions are collectively referred to as print conditions). And converts the image data for printing into image data for a printer based on the print profile and the printer profile. To create a proof image based on the image data for the printer. By doing so, it is possible to create a proof image in which the colors match the actual printed matter to some extent. Usually, printing profiles corresponding to typical printing conditions are provided by a printing company,
A printer profile is also provided by the manufacturer of the printer.

[0003]

However, even if a print profile and a printer profile are obtained or created, and color conversion is performed based on the print profile and the printer profile to create a proof image, various variance factors, Due to a combination of error factors, the color of the proof image may not sufficiently match the color of the image actually obtained by printing. In order to correct such color mismatch, the print profile is corrected based on the difference between the color of the image obtained by printing and the color of the proof image, thereby improving the color matching between the images. (See Japanese Patent Application No. 11-00875).

Here, there are various types of printers, and a system is constructed such that a printer for obtaining a proof image is selected from a plurality of types of printers according to, for example, a proof image creation speed and cost. if you did this,
The above-described method of correcting the print profile may cause a problem.

That is, in the above-described method of correcting a print profile based on a color difference between an image obtained by actual printing and a proof image created by a printer,
In the difference, both the variation factor and the error factor on the print profile side and the variation factor and the error factor on the printer profile side are mixed and entered, so the print profile corrected based on the difference is: This results in a print profile that can be used only in combination with the one printer (or one print condition). Therefore, when a new printer is added,
There is a problem that the corrected print profile is not suitable for a new printer and becomes unusable.

In order to solve this problem, a printer or a printing profile suitable for the printing condition is created for each type of printer (or for each printing condition), and a printer for creating a proof image and a printing condition for the printing condition are prepared. It is conceivable to use a printing profile suitable for the printer or the printing conditions according to the selection. However, print profiles are typically C (cyan), M (magenta), Y (yellow),
Between image data (four-dimensional data) for four colors of K (black) and three-dimensional data of colorimetric values, for example, L * a * b * (* is abbreviated below and simply abbreviated as Lab) L for conversion of
Since it is defined as a UT (look-up table) and requires a huge memory capacity, having such an LUT for each type of printer results in an excessively large memory capacity. Here, since only one print profile exists for each print condition, the number of print profiles is required by the number of combinations of print conditions and printers (print conditions), and an extremely large memory capacity is required. And not realistic.

The present invention has been made in view of the above circumstances, and is adapted to a system in which a plurality of types of printers for outputting a proof image are provided, so as to obtain a proof image having a color sufficiently matching the color of an image obtained by printing. A color conversion method, a color conversion device, a color conversion program storage medium storing a color conversion program for using a computer system as a color conversion device, and a color of a proof image sufficient for a color of a color print. It is an object to provide a color correction method for matching.

[0008]

According to the present invention, there is provided a color conversion method comprising the steps of:
When using a printer to output a proof image that reproduces the color of the image obtained when the image data defined in the color space is obtained by printing an image based on the image data under predetermined printing conditions, In a color conversion method for converting image data for a printer into image data defined in a second color space, the coordinate value in the first color space and the coordinate value in a device-independent colorimetric color space are converted. Defined the correspondence,
A print profile corresponding to a print condition, a printer profile corresponding to a print condition of a printer that outputs a proof image, and defining a correspondence between a coordinate value in the second color space and a coordinate value in the colorimetric color space; A correction profile for correcting the conversion definition for converting the coordinate values of the first color space into the coordinate values of the second color space, which is composed of the print profile and the printer profile, is used in the first color space. It is characterized in that the defined image data is converted into image data defined in the second color space.

When a proof image is created by using a print profile and a printer profile, the color of the proof image does not largely deviate from the color of an image obtained by actual printing, but usually almost matches, There are only significant differences. Therefore, the above correction profile requires a smaller memory capacity than the print profile itself or the printer profile itself.

In the color conversion method of the present invention, the print profile and the printer profile are left as they are, and the correction profile is prepared and used separately from the print profile and the printer profile. Only a small increase in the memory capacity is required, and a proof image in which colors match sufficiently can be created.

Here, in the color conversion method of the present invention, the image data defined in the first color space is replaced by a print profile in which the image data defined in the first color space is used as the correction profile. A correction profile for converting the converted image data in the colorimetric color space into correction data may be used, or the image data defined in the first color space may be printed as the correction profile. A correction profile for converting the image data in the colorimetric color space converted by the profile into correction data for correcting the image data in the colorimetric color space may be used. Alternatively, the first profile may be used as the correction profile. The image data defined in the first color space is converted into the print profile by the image data defined in the first color space. Or a correction profile that converts the image data in the colorimetric color space that has been converted into the correction data that corrects the image data in the second color space that has been further converted by the printer profile. As the correction profile, image data in a colorimetric color space obtained by converting image data defined in the first color space by a print profile is converted into image data defined in the first color space by a print profile. The second image data obtained by further converting the image data of the colorimetric color space thus formed by the printer profile.
May use a correction profile for converting image data in the color space into correction data for correction.

In any of the above correction profiles, a small memory capacity is required, and sufficient color matching can be obtained by using the correction profiles.

In the above-mentioned color conversion method of the present invention,
A combined profile is created by combining a print profile, a printer profile, and a correction profile, and the combined profile is used to convert image data defined in the first color space into an image defined in the second color space. It is preferable to convert the data.

By creating such a combined profile and using the combined profile, image data for printing defined in a first color space (for example, a CMYK color space) is converted into a second color space (for example, an RGB color space). Color space), the image data can be directly converted into image data for a printer defined in the color space, and the color conversion process can be speeded up.

In the present invention, for example, a print profile will be described by way of example. A print profile is defined in a first color space (usually a color space composed of four CMYK colors) describing image data for printing. It defines the relationship between coordinate values and coordinate values in a device-independent colorimetric color space (for example, a color space such as XYZ, Lab, etc.). In this case, coordinate values in the first color space are defined as coordinates in the colorimetric color space. It is necessary to distinguish between a value that is converted into a value and a method that converts a coordinate value of a colorimetric color space into a coordinate value of a first color space, which is referred to as a print profile. In some cases, a device that converts coordinate values in a device-dependent color space (first color space) into coordinate values in a device-independent colorimetric color space is referred to as a forward conversion print profile (or simply, a print profile). And is referred to as inverse transform print profile converts the coordinate values of the colorimetric color space of the device-independent coordinate values of a device-dependent color space (first color space). The same applies to other profiles such as a printer profile.

Further, the color conversion apparatus of the present invention prints image data defined in a first color space that describes image data for printing on the basis of the image data under predetermined printing conditions. When a proof image reproducing the color of the obtained image is output using a printer, a color conversion device that converts the proof image into image data defined by a second color space describing image data for a printer, A print profile storage unit that stores one or more print profiles corresponding to print conditions and that defines the correspondence between the coordinate values in the first color space and the coordinate values in the device-independent colorimetric color space; A printer that stores one or more printer profiles that define the correspondence between coordinate values in a color space and coordinate values in a colorimetric color space and that correspond to print conditions of a printer that outputs a proof image A conversion unit for converting the coordinate values in the first color space into coordinate values in the second color space, which are composed of the print profile and the printer profile corresponding to the combination of the print profile and the printer profile. A correction profile storage unit that stores a correction profile for correcting the definition for each combination of a print profile stored in the print profile storage unit and a printer profile stored in the printer profile storage unit, and a print profile specification that specifies the print profile Unit, a printer profile designating unit for designating a printer profile, and a print profile designated by the print profile designating unit read from the print profile storage unit, and a printer profile designated by the printer profile designating unit. The correction profile corresponding to the combination of the print profile and the printer profile designated by the print profile designation unit and the printer profile designation unit is read from the printer profile storage unit, and the read print profile and the printer are read out. A color conversion unit configured to convert image data defined in the first color space into image data defined in the second color space by using a profile and a correction profile.

The color conversion apparatus of the present invention stores a print profile and a printer profile, respectively,
The correction profile corresponding to the combination of the print profile and the printer profile is stored, and the print profile and the printer profile are read out in response to the designation of the print profile and the printer profile. The correction profile corresponding to the combination is read, and color conversion is performed using the read print profile, printer profile, and correction profile. By storing them, highly accurate color conversion can be performed.

Here, in the above-described color conversion apparatus of the present invention, the color conversion section stores a print profile, a printer profile, and a correction profile read from the print profile storage section, the printer profile storage section, and the correction profile storage section, respectively. It is preferable that a combined profile is created and the image data defined in the first color space is converted into image data defined in the second color space using the combined profile. .

At the time of actual color conversion, high-speed color conversion can be performed by creating such a combined profile and performing color conversion using the combined profile.

Further, the color conversion program storage medium of the present invention prints image data defined in a first color space describing image data for printing, and prints an image based on the image data under predetermined printing conditions. When using a printer to output a proof image that reproduces the color of the image obtained when
A color conversion program storage medium storing a color conversion program for converting into image data defined in a second color space describing image data for a printer,
And a print profile corresponding to printing conditions, which defines the correspondence between the coordinate values in the color space and the coordinate values in the device-independent colorimetric color space, and the coordinate values in the second color space and the coordinate values in the colorimetric color space. And a printer profile corresponding to the printing condition of the printer that outputs the proof image, and further, the coordinate values of the first color space, which are composed of the print profile and the printer profile, are converted into the second color space. A color conversion program for converting image data defined in the first color space into image data defined in the second color space is stored using a correction profile for correcting a conversion definition for converting to coordinate values. It is characterized by being done.

Here, in the color conversion program storage medium of the present invention, the color conversion program creates a combined profile in which a print profile, a printer profile, and a correction profile are combined, and uses the combined profile to create the combined profile. It is preferable to convert the image data defined in the first color space into the image data defined in the second color space.

According to the color conversion program stored in the color conversion program storage medium of the present invention, it can be loaded into a computer system and the computer system can realize the color conversion method of the present invention.

Although the method of obtaining the correction profile has not been described above, the correction profile can be obtained as follows.

That is, the color correction method of the present invention, which is based on the method of obtaining the correction profile, converts an image based on image data defined in a first color space that describes image data for printing into a predetermined printing condition. A color correction method for correcting a color reproduced on the proof image when the proof image reproducing the color of the image obtained by printing the image below is output using a printer; A print profile corresponding to the printing condition, which defines the correspondence between the coordinate values in the space and the coordinate values in the device-independent colorimetric color space, and a second color space that describes image data for a printer that outputs a proof image. Using a printer profile corresponding to the printing conditions of the printer, which defines the correspondence between the coordinate values and the coordinate values of the colorimetric color space, is defined in the first color space. The first image data representing the color chart is converted into second image data defined in the second color space, and a color chart based on the second image data is output by the printer, and is output. By measuring the color chart, a proofer profile before correction that defines the correspondence between the coordinate values of the first color space and the coordinate values of the device-independent colorimetric color space is obtained, and the print profile and the uncorrected proofer profile are determined. Based on the proofer profile or further based on the printer profile, the coordinate value of the first color space, which is composed of the print profile and the printer profile, is converted to the coordinate value of the second color space. A correction profile for correcting a conversion definition to be performed is obtained.

Here, in the color conversion method according to the present invention, the image data defined in the first color space is replaced by the image data defined in the first color space as the correction profile. Converting the image data of the colorimetric color space that has been converted into correction data, a correction profile consisting of a difference between the proofer profile before correction and the print profile may be obtained, or as the correction profile Converting the image data in the colorimetric color space obtained by converting the image data defined in the first color space by the print profile into correction data for correcting the image data in the colorimetric color space; A correction profile consisting of a combination with a proofer profile may be obtained. As the correction profile, image data defined in the first color space is converted from image data defined in the first color space by a print profile. A first combined profile, which is a combination of the proofer profile before correction and a printer profile, for converting the converted image data in the second color space into correction data for correction, and a print profile and a printer profile. A correction profile consisting of a difference from the second combination profile consisting of the combination may be obtained. Alternatively, as the correction profile, image data defined in the first color space is converted by a print profile. Image data in the colorimetric color space The image data in the colorimetric color space obtained by converting the defined image data by the print profile is further converted into the correction data for correcting the image data in the second color space obtained by the conversion by the printer profile. A correction profile composed of a difference between a printer profile and a combined profile composed of a previous proofer profile and a printer profile may be obtained.

Any one of these correction profiles can be obtained, and the conversion definition consisting of the print profile and the printer profile can be corrected using the correction profile to perform highly accurate color conversion.

[0027]

Embodiments of the present invention will be described below.

FIG. 1 is an overall configuration diagram of a printing and proof image creating system to which an embodiment of the present invention is applied.

In the color scanner 10, a document image is read, and the CMYK image representing the read document image is read.
Four color separation image data is generated. The CMYK image data is input to the workstation 20. In the workstation 20, the operator performs electronic plate collection based on the input image data, and generates image data representing an image for printing. The image data for printing is input to the film printer 30 when printing is performed, and the film printer 30 creates a CMYK printing film original corresponding to the input image data.

A printing plate is prepared from the printing film precursor, and the prepared printing plate is mounted on a printing press 40.
Ink is applied to the printing plate mounted on the printing press 40, and the applied ink is transferred onto printing paper to form an image 41 on the printing paper.

A series of operations for preparing a film original by the film printer 30, preparing a printing plate, mounting the printing plate on a printing machine 40, applying ink to the printing plate, and printing on paper, are extensive. It's work and costly. Therefore, before the actual printing operation is performed, the proof image 61 is created by the printer 60 as described below, and the finish of the print image 41 is checked in advance.

In creating a proof image, image data created by electronic printing on the workstation 20 is input to the personal computer 50.
Here, the image data input to the personal computer 50 is a so-called PDL (Page Deccr).
description language data), and in the personal computer 100,
So-called RIP (Raster Image Proc)
ESSOR), CMY expanded to a bitmap
It is converted to K4 color image data. The image data of the four colors CMYK is substantially the same as the image data for printing input to the film printer 30.

The print image data of the four colors CMYK is stored in the personal computer 50 in the LUT.
A color conversion definition having the format of (Look Up Table) is referred to, and RGB three-color images suitable for a printer (here, the printer 60a) which is to output a proof image among a plurality of printers 60a,. Converted to data. The printer 60a has the R
The image data of three colors of RGB is input, and the printer 60a creates a proof image 61 based on the input image data of three colors of RGB.

Here, the degree of color matching between the image 41 obtained by printing by the printing machine 40 and the proof image obtained by the printer 60a is determined by the color conversion definition in the personal computer 50. This color conversion definition is created for each printing condition for each printer.

Although only one printing press is shown in FIG. 1, a plurality of printing presses may be provided, or even a single printing press may have different printing conditions. Alternatively, the color conversion definition may be created in accordance with each of a plurality of printing conditions including differences between printing presses. That is, the color conversion definition is created according to a combination of each of the printing conditions and each of the printers (when a plurality of printing conditions exist in one printer, each of the printing conditions). The method of creating the color conversion definition will be described later. The colorimeter 200 shown in FIG. 1 relates to the creation of the color conversion definition, and will be described later.

By creating a proof image and confirming the proof image in this way, the finish of printing can be confirmed in advance.

Here, the feature of one embodiment of the present invention in the proof image creating system shown in FIG. 1 lies in the processing contents executed inside the personal computer 50.
Will be described.

FIG. 2 is an external perspective view of the personal computer 50 shown by one block in FIG. 1, and FIG. 3 is a hardware configuration diagram of the personal computer 50.

The personal computer 50 has a main body device 51, an image display device 52 for displaying an image on a display screen 52a in response to an instruction from the main device 51, and a main device 51 in response to a key operation. A keyboard 53 for inputting various types of information, and a mouse 5 for designating an arbitrary position on the display screen 52a to input an instruction corresponding to, for example, an icon displayed at the position.
4 is provided. The main unit 51 has a floppy disk loading port 51a for loading a floppy disk, and a CD-ROM for loading a CD-ROM.
It has a ROM loading port 51b.

As shown in FIG. 3, a CPU 511 for executing various programs and a main memory 51 for reading out programs stored in a hard disk drive 513 and developing them for execution by the CPU 511 are provided inside the main unit 51.
2. A hard disk drive 513 storing various programs, data, etc., an FD driver 514 for loading the floppy disk 100 and accessing the loaded floppy disk 100, a CD-ROM 110 being loaded, and loading the loaded CD-ROM 110 CD-ROM driver 515 to access, workstation 20
(See FIG. 1), an I / O interface 516 for receiving image data from the workstation 20, and printer interfaces 517a,..., 517n for transmitting image data to the respective printers 60a,. The various elements and the image display device 52, the keyboard 53, and the mouse 54 also shown in FIG.
Connected to each other.

Here, a color conversion program for operating the personal computer 50 as a color conversion device is stored in the CD-ROM 110.
The ROM 110 is loaded into the CD-ROM driver 515, and the color conversion program stored in the CD-ROM 110 is uploaded to the personal computer 50 and stored in the hard disk device 513.

Here, when one embodiment of the color conversion program of the present invention is stored in the CD-ROM 110,
The CD-ROM 110 corresponds to an embodiment of the color conversion program storage medium of the present invention. When the color conversion program is uploaded and stored in the hard disk device 513, the color conversion program is stored. The hard disk device 513 also corresponds to an embodiment of the color conversion program storage medium of the present invention. Further, when the color conversion program is downloaded to the floppy disk 100, the floppy disk 100 in which the color conversion program is stored also corresponds to an embodiment of the color conversion program storage medium of the present invention.

Next, a method of creating a color conversion definition constructed in the personal computer 50 will be described.

FIG. 4 is a flowchart showing a procedure for creating a color conversion definition.

Here, first, a print profile is created (step (a)). As described above, a printing profile corresponding to typical printing conditions is often provided by a printing company, and if a printing profile corresponding to desired printing conditions can be obtained, this step (a) is unnecessary. However, here, a basic creation method when the print profile is newly created will be described.

From the workstation shown in FIG.
The halftone% data of the K4 color is, for example, 0%, 10%,.
The color patch image is sequentially changed to 0%, and a color patch image based on the halftone% data thus generated is created according to the above-described printing procedure. Although the image 41 shown in FIG. 1 is not an image representing a color patch image, it is assumed that a color patch image is printed in place of the image 41, and each color patch constituting the color patch image is Measure with In this way, a print profile is created that represents the correspondence between the coordinate values of the four CMYK colors in the color space and the coordinate values of the colorimetric color space.

FIG. 5 is a conceptual diagram of a print profile.

CMYK image data (image data defined in the first color space of the present invention) is input to this print profile, and the CMYK image data is
(Image data defined in the colorimetric color space according to the present invention).

Here, the CMYK image data is represented by L
A printing profile (forward conversion printing profile) for converting to ab image data is represented by T, and a reverse conversion thereof, that is, a printing profile (reverse conversion printing profile) for converting Lab image data to CMYK image data is represented by T.
^Represented by ^-1 .

Next, a printer profile is created (step (b) in FIG. 4). As described above, a printer profile is often provided by a printer maker, and corresponds to a desired printer (or desired printing conditions when the printer is a printer capable of performing print output under a plurality of printing conditions). This step (b) is unnecessary if a printer profile can be obtained. Here, a basic method of creating a new printer profile will be described. The method of creating a printer profile is the same as the method of creating a print profile described above.

Here, a plurality of printers 60 shown in FIG.
, 60n, a printer profile for the printer 60a is created.
Is a printer that outputs an image based on image data of three colors of RGB (an example of the second color space according to the present invention).

Here, in the personal computer 50 shown in FIG. 1, the image data of the three colors RGB is sequentially changed from a minimum value (for example, 0) to a maximum value (for example, 255) for each color in predetermined increments (for example, increments of 8). A color patch image is created based on the image data that has been changed and generated in this way. Although the image 61 shown in FIG. 1 is not an image representing a color patch image, this image 61
Is output in place of the color patch image, and each color patch constituting the color patch image is output to the colorimeter 20.
Measure the color at 0. By doing so, a printer profile that represents the correspondence between the coordinate values in the RGB three color space and the coordinate values in the colorimetric color space for the printer 60a is constructed.

FIG. 6 is a conceptual diagram of a printer profile.

In this printer profile, RGB image data is input, and the RGB image data is
b is converted into image data. Here, this RGB
The printer profile (forward conversion printer profile) for converting the image data of No. into Lab image data is represented by P, and the reverse conversion thereof, that is, the Lab image data
A printer profile (inverse conversion printer profile) to be converted into GB image data is represented by P- ¹ .

Although the printer 60a has been described as a printer that outputs an image based on RGB image data, the printer that outputs an image based on CMYK image data, for example, may also be a CMYK printer. By generating image data defined in space and outputting a color patch image, a printer profile suitable for the printer can be created in the same manner. Here, a description will be given assuming that a printer 60a that outputs an image based on RGB image data is used.

FIG. 7 is a view showing a combined profile obtained by combining a print profile and a printer profile.

The CMYK image data is converted to Lab image data by the print profile T,
The image data b is converted into RGB image data by the inverse conversion printer profile P- ¹ . Based on the RGB image data generated in this manner, the printer 60a can output a proof image of the same color as that of the printing. A combined profile P consisting of a combination of this print profile T and the inverse transform printer profile P ^-1
-1 (T) is a kind of color conversion definition for converting from the CMYK color space to the RGB color space.

Here, even if a proof image is output by the printer 60a based on the image data that has undergone color conversion according to the color conversion definition, the color of the proof image is
The problem is that the colors may not always match the color of the image obtained by 0. In order to solve this problem, the following procedure is further performed.

In step (c) of FIG. 4, a proofer profile before correction is created as follows.

FIG. 8 is a conceptual diagram of a proofer profile before correction.

As described with reference to FIG. 7, the CMYK image data for printing is converted into image data for the printer 60a by using the combined profile of the print profile T and the inverse conversion printer profile P- ^1. can do. Therefore, here, step (a) in FIG.
As in the case of creating a print profile in
By sequentially changing the values of the CMYK image data, image data representing a color patch is sequentially generated, and the image data is converted into an image data according to a combined profile of a print profile T and an inverse conversion printer profile P- ^1.
The image data is converted into GB image data, the image data is sent to the printer 60a, and the printer 60a outputs a color patch image. Here, the profile P of the actual printer 60a shown in FIG. 8 should be exactly the same as the profile of the reverse conversion printer profile P- ¹ , except for the difference of the forward conversion or the reverse conversion. However, actually, they do not always match due to various fluctuation factors and error factors. Therefore, here, each color patch constituting the color patch image thus output is measured by the colorimeter 200 (see FIG. 1). By doing so, CMY for printing
A profile representing the relationship between the coordinate values in the K space and the coordinate values in the Lab space (here, this profile is referred to as a pre-correction proofer profile F) is constructed.

Next, in step (d) of FIG. 4, a correction profile is created. This correction profile is obtained based on the proofer profile before correction and the print profile obtained as described above, or further based on the printer profile of the printer 60a which is to output a proof image. With this correction profile, the color conversion definition is corrected so that a proof image in which colors match with higher accuracy is obtained than when a color conversion definition consisting of a combined profile of a printing profile and an inverse conversion printer profile is used as it is. .

How to obtain this correction profile, and
As described below, there are a plurality of color conversion definitions including the correction profile.

FIG. 9 is an explanatory diagram of a first example of a correction profile and a first example of a color conversion definition including the correction profile.

Here, Δ = FT is obtained as the correction profile Δ. In this case, this correction profile Δ
A correction profile for converting the CMYK coordinates to the coordinate values of the Lab, as expressly this, delta _Lab (CMY
K).

Here, the correction profile Δ is multiplied by a weight coefficient w. Here, as an example, the weight coefficient is set to 0 outside the color reproduction range of the printer 60a in the CMYK space, and is set to -1 within the color reproduction range of the printer 60a by adding a minus sign for convenience of calculation.

The correction profile Δ is created, and
When the proof image is actually output by the printer 60a, a color conversion definition as shown in FIG. 9 is used. That is, the CMYK image data for printing is input to both the print profile T and the weighted correction profile w · Δ, and is converted into Lab image data and Lab correction data, respectively. The data and the correction data are added. Since the weight coefficient w has a minus sign, this addition is actually a subtraction. The image data in the Lab space to which addition (subtraction) has been performed in this manner is input to the inverse conversion printer profile P- ¹ , and is converted into RGB image data. This RG
The B image data is sent to the actual printer 60a, and the printer 60a creates a proof image based on the RGB image data.

The proof image created in this manner is different from the case where the color conversion is performed using the color conversion definition which does not employ the correction profile Δ shown in FIG. A proof image having a high degree of matching with the color is obtained.

Here, as shown in FIG. 9, by providing the correction profile Δ separately from the print profile T, if the number of printers increases, the correction profile Δ that requires a small memory capacity can be increased. In comparison with the case where the print profile T is directly corrected and the print profile is rewritten, the increase in the memory capacity when the number of printers is increased can be reduced.

In FIG. 9, the printing profile T, the correction profile w · Δ, and the inverse conversion printer profile P ^{−1 are shown.}
Are shown in the three profile blocks,
In actual color conversion, these three profiles are combined to create one combined profile in the LUT format, and color conversion is performed by referring to the LUT. This makes it possible to perform color conversion at a higher speed than when referring to a plurality of profiles separately.

FIG. 10 is an explanatory diagram of a second example of the correction profile and a second example of the color conversion definition including the correction profile.

Here, the correction profile Δ is Lab color
Image data in the same Lab color space
A correction profile to be converted to correction data to be corrected.
And Δ _Lab(Lab). The weighting factor w is
9 has the same meaning as described with reference to FIG.
Printer in Lab color space, which is the output of profile T
The value outside the color reproduction range of 60a is set to 0,
Within the color reproduction range of a, a minus sign is added for convenience of calculation.
-1.

Here, the coordinate values in the Lab space are converted to the coordinate values in the CMYK color space by a print profile (inverse conversion print profile T ^-1 ) for converting the coordinate values in the Lab color space into the coordinate values in the CMYK color space for printing. And a coordinate profile obtained by the conversion is further converted to a coordinate value in the Lab color space by the proofer profile F before correction again to obtain a joint profile S = F (T ^-1 ), which is input in the Lab space. Considering a profile in which the coordinate values of and the output are always the same, letting this be E, the correction profile Δ _Lab (Lab) is obtained by Δ _Lab (Lab) = SE.

When such a correction profile is created, the color conversion definition shown in FIG. 10 is adopted when an actual proof image is created by the printer 60a. That is, the image data in the Lab color space obtained by converting the CMYK image data for printing by the print profile T is input to the weighting correction profile w · Δ,
The image data in the Lab color space converted into the correction data in the ab color space and converted by the print profile T is corrected by the correction data, and the corrected image data in the Lab color space is converted into the inverse conversion printer profile P ^-1. And converted into RGB image data. The RGB image data obtained by such conversion is sent to the actual printer 60a, and the printer 60a creates a proof image based on the RGB image data.

The proof image created in this manner is obtained by performing color conversion using the color conversion definition that does not employ the correction profile shown in FIG. 7, as in the comparison in the case of the first example shown in FIG. As compared with the proof image, a proof image that matches the color of the printed image with high accuracy can be obtained.

Further, in the second example shown in FIG. 10, by providing the correction profile Δ separately from the print profile T, compared with the case where the print profile itself is rewritten, the memory capacity when the number of printers increases is increased. The point that the increase is small is the same as in the case of the first example shown in FIG.

Further, similarly to the case of the first example shown in FIG. 9, in actual color conversion, three profiles of a printing profile T, a correction profile w · Δ, and an inverse conversion printer profile P- ¹ are combined. Thus, one LUT is created, and color conversion is performed by referring to the LUT. This makes it possible to perform color conversion at a higher speed than when referring to a plurality of profiles separately.

FIG. 11 is an explanatory diagram of a third example of the correction profile and a third example of the color conversion definition including the correction profile.

Here, a correction profile Δ for converting image data in the CMYK color space for printing into correction data in the RGB color space for a printer is created and used. This correction profile Δ is expressed as Δ _RGB (CMYK).

Here, Q = P ^-1 (T) R = P ^-1 (F) is obtained as two conversion systems Q and R from CMYK to RGB, and a correction profile Δ is obtained from the difference.

Δ _RGB (CMYK) = RQ Here, Q = P ⁻¹ (T) means that the coordinate values of the CMYK color space are once converted into the coordinate values of the Lab color space by the print profile T, and then the Lab values are obtained. R = P ^-1 (F) denotes a conversion system for converting the coordinate values of the color space into the coordinate values of the RGB color space by the inverse conversion printer profile P ^-1 . Profile F (FIG. 8)
), And then converts the coordinate values in the Lab color space to the coordinate values in the RGB color space by the inverse conversion printer profile P- ^1. w has the same meaning as in FIGS. 9 and 10. Here, as an example, w is set to 0 for an area outside the color reproduction range of the printer 60a in the CMYK color space for printing, and For the area within the color reproduction range, a minus sign is added to −1 for convenience of calculation.

The correction profile Δ _RGB (CM
When YK) is created, the color conversion definition shown in FIG. 11 is adopted when a proof image is actually created by the printer 60a. That is, the CMYK image data for printing includes the print profile T and the weighting correction profile w · Δ
And in the print profile T, the input CMYK image data is converted into Lab image data. The Lab image data obtained by this conversion is converted into RGB image data by the inverse conversion printer profile P- ¹ . On the other hand, the weighting correction profile w
In Δ, the input CMYK image data is converted to RGB correction data, and the correction data corrects the RGB image data obtained by the inverse conversion printer profile P- ¹ . The corrected RGB image data is sent to the actual printer 60a, and the printer 60a creates a proof image based on the RGB image data. The proof image created in this manner is similar to the first and second examples described with reference to FIG. 9 and FIG. Compared to the case of performing color conversion using the color conversion definition consisting of ^-1 ,
The printed image and the color match with high accuracy.

Also, by having a correction profile separately from a print profile and a printer profile, an increase in the memory capacity when the number of printers is increased can be achieved only by a correction profile having a small required memory capacity. This is the same as in the first and second examples.

Further, in performing the actual color conversion, one LUT representing one combined profile is created by combining the print profile T, the inversely-converted printer profile P ⁻¹ , and the correction profile w · Δ. One LUT is referenced and RGB from CMYK color space
High-speed color conversion to the color space is performed. This point is also the same as in the first and second examples.

FIG. 12 is an explanatory diagram of a fourth example of the correction profile and a fourth example of the color conversion including the correction profile.

Here, the correction profile Δ is arranged in parallel with the inverse conversion printer profile P- ^1, and in the correction profile, Lab image data is converted into RGB correction data. That is, here, the correction profile Δ is described as Δ _RGB (Lab).

Here, the conversion definition shown in FIG. 12 is adopted. That is, the image data of Lab obtained CMYK image data for printing is converted by the print profile T is input to the inverse transform printer profile P ^-1, entered the inverse transform printer profile P ^-1 L
The ab image data is converted to RGB image data.
On the other hand, the same image data as the Lab image data input to the inverse conversion printer profile P ⁻¹ is input to the weight correction profile w · Δ, and the inverse correction printer profile P ⁻¹ is used for the weight correction profile w · Δ.
For correcting the RGB image data obtained by
Correction data in the B color space is generated. The RGB image data obtained by the inverse conversion printer profile P ^-1 is the RGB image data obtained by the weight correction profile w · Δ.
The corrected RGB image data is transmitted to the printer 60a, and a proof image based on the RGB image data is created in the printer 60a.

Here, the correction profile Δ in the case of the fourth example shown in FIG. 12 is created as follows.

That is, here, L is calculated from the Lab color space.
The conversion system S to the ab color space is obtained as S = F (T ⁻¹ ), and the conversion system U from the Lab color space to the RGB color space is obtained as U = P ⁻¹ (S), and the correction profile Δ _RGB the (Lab), obtained as _{Δ RGB (Lab) = U-} P -1.

Here, for S = F (T ^-1 ), FIG.
0 has already been described in the description of the second example shown in FIG.
The coordinate values in the color space are converted into the coordinate values in the CMYK color space for printing by the inverse conversion printing profile T ^{-1, and} the coordinate values in the CMYK color space obtained by this conversion are again converted by the proofer profile F before correction. U = P ^-1 (S) means that the coordinate values of the Lab color space after the conversion are converted to the RGB colors by the inverse conversion printer profile P ^-1. It means to convert to space coordinate values. Further, Δ _RGB (Lab) = UP ⁻¹ is obtained from the coordinate values of the RGB color space obtained by the conversion of T ⁻¹ → F → P ⁻¹ as described above, ie, the original conversion system. Means subtracting the coordinate values in the RGB color space obtained by directly converting the coordinate values in the Lab color space before being input to the inverse conversion printing profile T ^-1 with the inverse conversion printer profile P ^-1 . By going through this operation,
Correction profile delta _RGB in the fourth example (Lab)
Can be requested.

The weighting factor w is calculated according to the first example to date.
It has the same meaning as the third example. For example, La
In the b color space, the area outside the color reproduction range of the printer 60a is set to 0, and the area within the color reproduction range of the printer 60a is set to -1 with a minus sign for convenience of calculation. In the case of the fourth example shown in FIG. 12, similarly to the first to third examples described above, the print profile T and the inverse conversion printer profile P- ¹ are used without using the correction profile Δ. As compared with the case where color conversion is performed using the color conversion definition, a proof image in which colors match with high accuracy can be obtained.

Further, by having the correction profile separately from the print profile and the printer profile, the degree of increase in the memory capacity when the number of printers increases can be suppressed. Same as in the case.

Further, the actual color conversion is performed by synthesizing one LUT and performing the color conversion at a high speed using the LUT, which is not different from the first to third examples.

FIG. 13 is a functional block diagram of an embodiment of the color conversion apparatus of the present invention. This color converter is shown in FIG.
This is realized by combining the personal computer 50 shown in FIG. 3 with a program executed by the personal computer 50.

FIG. 13 shows a print profile storage unit 501, a printer profile storage unit 502, and a correction profile storage unit 503. The print profile 501 includes a plurality of print profiles 501a corresponding to a plurality of print conditions. , 501x are stored, and a plurality of printer profiles 502a, 502b,..., 502y respectively corresponding to a plurality of printers (or a plurality of printing conditions including the type of printer) are stored in the printer profile storage unit 502. The correction profile storage unit 503 stores a plurality of correction profiles 503 corresponding to a combination of the print profile stored in the print profile storage unit 501 and the printer profile stored in the printer profile storage unit 502.
, 503b are stored. That is, if one print profile is specified and one printer profile is further specified, one correction profile is determined. This correction profile storage unit 503
Correction profiles 503a and 503 stored in
, 503z may be correction profiles of any of the various types of correction profiles described with reference to FIGS. 9 to 12, and may include correction profiles of a plurality of types. Good.

The print profile and the printer profile stored in the print profile storage unit 501 and the printer profile 502 may be the forward conversion profile in the definition described above, may be the reverse conversion profile, and may be the forward conversion profile. Both the inverse transformation profile and the inverse transformation profile may be stored as a pair. The color conversion unit 506 described below determines whether the read profile is a forward conversion profile or an inverse conversion profile.
As necessary, the forward profile is changed to the reverse profile, or the reverse profile is changed to the forward profile, and then the combined profile 506a is generated.

Here, the print profile storage unit 501,
The printer profile storage unit 502 and the correction profile storage unit 503 are set in hardware inside the hard disk device 513 shown in FIG.

The color conversion apparatus shown in FIG. 13 includes a print profile designation section 504 and a printer profile designation section 505. From the print profile designation unit 504, information for designating a print profile, such as the name of a printing company, the name of the print condition when a name is given to the print condition, or the type of printing machine or the type of ink Information such as the type of paper on which printing is performed is input. In this color conversion device, a plurality of print profiles 501a, 501b, and 501 stored in a print profile storage unit 501 are stored based on the input information.
, 501x, a print profile suitable for the information is read, and the read print profile is input to the color conversion unit 506.

Also, a printer profile designation section 505
Can be used to specify a printer profile, for example, a one-to-one correspondence between a printer and a printer profile.
When a plurality of types of printing conditions exist for a single printer, the printer name and the name of the printing condition are specified. When information sufficient to specify a printer profile is input from the printer profile specifying unit 505, a printer profile specified by the information is read from the printer profile storage unit 502 and input to the color conversion unit 506.

Further, as described above, the print profile designation unit 504 and the printer profile designation unit 50
5, the information for specifying the print profile and the information for specifying the printer profile
Both of them are input to the correction profile storage unit 503, and the correction profile specified by the information of both of them is read from the correction profile storage unit 503, that is, the correction profile specified by the combination of the print profile and the printer profile is read out, and the color The data is input to the conversion unit 506.

Note that the print profile designation unit 504 and the printer profile designation unit 505 are provided on the keyboard 53 or the mouse 5 shown in FIGS.
4 plays both roles.

In the color conversion unit 506, as described above,
A print profile, a printer profile, and a correction profile are input, and the three profiles are combined to create one combined profile in the form of an LUT. The method of combination in this case, that is, the color conversion definition to be adopted, is such that the correction profile input to the color conversion unit 506 has any of the various types of correction profiles described with reference to FIGS. The color conversion definition according to the format of the correction profile described with reference to FIGS. 9 to 12 according to the format of the input correction profile is adopted depending on whether the correction profile is the correction profile.

After one LUT is created in this way, PDL image data for a print image created by electronic printing is input from the workstation 20 shown in FIG. The data is converted into bitmap format image data by RIP, and the bitmap format image data defined in the CMYK color space for printing is input to the color conversion unit 506, and is built in the color conversion unit 506. The LUT converts the image data into image data in the RGB color space of the printer corresponding to the printer profile specified by the printer profile specifying unit 505.

The image data in the RGB color space obtained by the color conversion unit 506 is transmitted to a printer corresponding to the printer profile, and the printer outputs a proof image in which the color of the image obtained by printing matches the color of the image to a high degree. You.

According to the color conversion apparatus shown in FIG. 13, since the correction profile is stored separately from the print profile and the printer profile, even if the number of printers increases, the necessary memory increases. The capacity is small and a proof image in which colors match with high accuracy can be obtained.

Here, for simplicity, all printers have been described as outputting images based on RGB image data. However, printers that output images based on CMYK image data are used. Or both printers may be mixed. When a printer that outputs an image based on CMYK image data is used for proof image output, the color conversion unit 56 sets the combined profile as CMYK for printing.
An LUT for converting K image data into CMYK image data for a printer is created, and color conversion is performed based on the LUT.

FIG. 14 is a diagram showing an embodiment of the color conversion program storage medium of the present invention.

The type of the storage medium 600 shown in FIG. 14 does not matter as long as it is a storage medium storing the color conversion program 610. For example, the CD-RO shown in FIG.
When the color conversion program 610 is stored in the M110, the CD-ROM 110 is pointed out. When the color conversion program is loaded and stored in the hard disk drive 513 shown in FIG. The color conversion program 610
Is downloaded to the floppy disk 100 shown in FIG.

Here, the color conversion program 610 stored in the storage medium 600 shown in FIG. 14 includes a combination profile creation unit 611, a color conversion unit 612, and various other units.

The connection profile creation means 611 and the color conversion means 612 constitute a software part of the color conversion unit 506 of the color conversion apparatus shown in FIG. Means for creating a combined profile as one LUT by combining the print profile, printer profile, and correction profile thus obtained,
CM for printing input using the created LUT
The image data in the YK color space is converted into, for example, RG
It is means for converting into image data in the B color space.

Other means constituting the color conversion program 610 shown in FIG. 14 include, for example, means for supporting the operation of creating a correction profile described with reference to FIG.
A means for forming a print profile storage unit 501, a printer profile storage unit 502, and a correction profile storage unit 503 shown in FIG. 13 in the hard disk device 513 shown in FIG. 3, and storing and managing various profiles therein, Means for receiving operations of the keyboard 53 and the mouse 54 shown in FIG.

[0112]

As described above, according to the present invention, even if the number of printers for outputting a proof image increases, the color can be accurately adjusted while suppressing the increase in the memory capacity. A matched proof image can be obtained.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a printing and proof image creating system to which an embodiment of the present invention is applied.

FIG. 2 is an external perspective view of the personal computer.

FIG. 3 is a hardware configuration diagram of a personal computer.

FIG. 4 is a flowchart illustrating a procedure for creating a color conversion definition.

FIG. 5 is a conceptual diagram of a print profile.

FIG. 6 is a conceptual diagram of a printer profile.

FIG. 7 illustrates a combined profile obtained by combining a print profile and a printer profile.

FIG. 8 is a conceptual diagram of a proofer profile before correction.

FIG. 9 is an explanatory diagram of a first example of a correction profile and a first example of a color conversion definition including the correction profile.

FIG. 10 is an explanatory diagram of a second example of a correction profile and a second example of a color conversion definition including the correction profile.

FIG. 11 is an explanatory diagram of a third example of a correction profile and a third example of a color conversion definition including the correction profile.

FIG. 12 is an explanatory diagram of a fourth example of a correction profile and a fourth example of a color conversion definition including the correction profile.

FIG. 13 is a functional block diagram of a color conversion device according to an embodiment of the present invention.

FIG. 14 is a diagram showing one embodiment of a color conversion program storage medium of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Color scanner 20 Workstation 30 Film printer 40 Printing machine 41 Image 50 Personal computer 51 Main unit 51a Floppy disk loading port 51b CD-ROM loading port 52 Image display device 52a Display screen 53 Keyboard 54 Mouse 55 Bus 60a, ..., 60n Printer 61 Proof image 100 Floppy disk 110 CD-ROM 200 Colorimeter 501 Print profile storage unit 501a, 501b, ..., 501x Print profile 502 Printer profile storage unit 502a, 502b, ..., 502y Printer profile 503 Correction profile storage unit 503a, 503b , .., 503z correction profile 504 print profile designation unit 505 printer profile designation unit 506 Color conversion unit 506a Connection profile 511 CPU 512 Main memory 513 Hard disk drive 514 FDD driver 515 CD-ROM driver 516 I / O interface 517a,..., 517n Printer interface 600 Storage medium 610 Color conversion program 611 Color conversion means 612 Color conversion means

Claims (15)

[Claims] An image data defined in a first color space that describes image data for printing, obtained by printing an image based on the image data under predetermined printing conditions. A color conversion method for converting image data for the printer into image data defined by a second color space when the proof image reproducing the image is output using a printer, Defines the correspondence between the coordinate values and the coordinate values of the device-independent colorimetric color space, and defines the correspondence between the print values corresponding to the printing conditions and the coordinate values in the second color space and the coordinate values of the colorimetric color space. A printer profile corresponding to the printing conditions of the printer that outputs the proof image, and the coordinate values of the first color space, which are composed of the print profile and the printer profile. The image data defined in the first color space is converted to image data defined in the second color space using a correction profile that corrects a conversion definition that converts the coordinate value into a coordinate value in the second color space. A color conversion method characterized by performing conversion. 2. The method according to claim 1, wherein the first correction profile is the first correction profile.
A correction profile for converting image data defined in the color space of the first color space into correction data for correcting image data in a colorimetric color space obtained by converting the image data defined in the first color space by the print profile. The color conversion method according to claim 1, wherein: 3. The method according to claim 1, wherein the first correction profile is the first correction profile.
And a correction profile for converting image data in a colorimetric color space obtained by converting image data defined in the color space by the print profile into correction data for correcting the image data in the colorimetric color space. Claim 1
The described color conversion method. 4. The method according to claim 1, wherein the correction profile is a first profile.
Image data defined in the color space of the first color space, the image data of the colorimetric color space obtained by converting the image data defined in the first color space by the print profile is further converted by the printer profile 2. A color conversion method according to claim 1, wherein a correction profile for converting image data in the second color space into correction data is used. 5. The first profile as the correction profile.
Color image space defined by converting the image data defined in the color space according to the print profile to colorimetric color space defined by converting the image data defined in the first color space by the print profile 2. The color conversion method according to claim 1, further comprising using a correction profile for converting image data of the second color space obtained by converting the image data of the second color space into correction data for correcting the image data. 6. A combined profile is created by combining the print profile, the printer profile, and the correction profile, and using the combined profile,
2. The color conversion method according to claim 1, wherein the image data defined in the first color space is converted into image data defined in the second color space. 7. A color of an image obtained by printing image data defined in a first color space describing image data for printing under a predetermined printing condition based on the image data. A color conversion device that converts image data for the printer into image data defined by a second color space when the proof image reproducing the image is output using a printer. A print profile storage unit that stores one or more print profiles corresponding to printing conditions and that defines the correspondence between the coordinate values and the coordinate values of the device-independent colorimetric color space; A printer profile storage unit that stores one or more printer profiles corresponding to the printing conditions of the printer that outputs the proof image and that defines the correspondence with the coordinate values of the color space; Corresponding to the combination of the file and the printer profile, consisting of these printing profile and the printer profile, the first of the coordinate values of the color space second
A correction profile for correcting a conversion definition for converting to a coordinate value of a color space of each of a combination of a print profile stored in the print profile storage unit and a printer profile stored in the printer profile storage unit. A storage unit, a print profile specification unit that specifies a print profile, a printer profile specification unit that specifies a printer profile, and a print profile specified by the print profile specification unit is read from the print profile storage unit, and the printer profile The printer profile designated by the designation section is read from the printer profile storage section, and the print profile designated by the print profile designation section and the printer profile designated by the printer profile designation section are further read. The correction profile corresponding to the combination with the printer profile is read from the correction profile storage unit, and the image data defined in the first color space is read using the read print profile, printer profile, and correction profile. A color conversion unit that converts the image data into image data defined in a second color space. 8. The color conversion unit creates a print profile read from the print profile storage unit, the printer profile storage unit, and the correction profile storage unit, and a combined profile in which the printer profile and the correction profile are combined. 8. The color conversion method according to claim 7, wherein the image data defined in the first color space is converted into image data defined in the second color space using the combination profile. Conversion device. 9. The color of an image obtained when image data defined in a first color space describing image data for printing is obtained by printing an image based on the image data under predetermined printing conditions. Storing a color conversion program for storing a color conversion program for converting image data for the printer into image data defined in a second color space when the proof image reproducing the image is output using the printer. A medium, comprising: a print profile corresponding to a printing condition, defining a correspondence between coordinate values in the first color space and coordinate values in a device-independent colorimetric color space; and coordinate values in the second color space. A printer profile corresponding to the printing conditions of the printer that outputs the proof image, which defines the correspondence between the profile and the coordinate values of the colorimetric color space. An image defined in the first color space using a correction profile for converting a coordinate value in the first color space into a coordinate value in the second color space, the correction profile being composed of a profile file. A color conversion program storage medium storing a color conversion program for converting data into image data defined in the second color space. 10. The color conversion program creates a combined profile in which the print profile, the printer profile, and the correction profile are combined, and defines the first profile in the first color space using the combined profile. 10. The color conversion program storage medium according to claim 9, wherein the image data is converted into image data defined in the second color space. 11. A proof image that reproduces the color of an image obtained by printing an image based on image data defined in a first color space that describes image data for printing under predetermined printing conditions. A color correction method for correcting a color reproduced on the proof image when the image is output using a printer, wherein a correspondence between a coordinate value in the first color space and a coordinate value in a device-independent colorimetric color space A print profile corresponding to printing conditions, and a correspondence between coordinate values in a second color space and coordinate values in a colorimetric color space that describe image data for a printer that outputs a proof image. The first image data representing the color chart defined in the first color space is converted into the second image data defined in the second color space by using a printer profile corresponding to the printing condition of By converting the image data, a color chart based on the image data of the second output by the printer, to colorimetry the outputted color chart,
Finding a pre-correction proofer profile that defines the correspondence between the coordinate values of the first color space and the coordinate values of the device-independent colorimetric color space, based on the print profile and the pre-correction proofer profile, or Further, based on the printer profile, a correction profile for correcting a conversion definition for converting a coordinate value of the first color space into a coordinate value of the second color space, the correction profile including the print profile and the printer profile. A color correction method characterized by being obtained. 12. An image in a colorimetric color space obtained by converting the image data defined in the first color space as the correction profile and the image data defined in the first color space by the print profile. 12. The color correction method according to claim 11, wherein a correction profile, which is a difference between the proofer profile before correction and the print profile, for converting data into correction data for correction is obtained. 13. The image data in a colorimetric color space obtained by converting image data defined in the first color space by the print profile, as the correction profile.
12. The color correction method according to claim 11, further comprising: obtaining a correction profile formed by combining the print profile and the proofer profile before correction, which converts the image data in the colorimetric color space into correction data for correction. 14. An image in a colorimetric color space obtained by converting the image data defined in the first color space as the correction profile and the image data defined in the first color space by the print profile. Converting image data of the second color space, which is obtained by further converting the data by the printer profile, into correction data for correcting the image data,
A first combined profile consisting of a combination of the pre-correction proofer profile and the printer profile;
12. A correction profile comprising a difference between a second combined profile formed by combining the print profile and the printer profile.
The color correction method described. 15. As the correction profile, image data in a colorimetric color space obtained by converting image data defined in the first color space by the print profile is defined in the first color space. Converting the image data of the colorimetric color space obtained by converting the image data by the print profile into correction data for correcting the image data of the second color space further converted by the printer profile; 12. The color correction method according to claim 11, wherein a correction profile including a difference between the printer profile and a combined profile including a proofer profile before correction and the printer profile is obtained.