JP2000004369A - Method and processor for image processing, and recording medium thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct a color conversion table more efficiently by referring to correction history information as to a specific color for correcting the color conversion table of a color converting means, so that a specific color input image matches that color of an output image. SOLUTION: An operator compares a test image on a display device 1 with its printed matter to select unmatched color between both images. A profile correction part 10 reads in information from a correction history information storage part 9 and display past correction history information, regarding color outputs at the grating points on the display device 1. While considering past correction history information, the operator sets an output value considered to be optimum at the grating point. The profile correction part 10 additionally stores the corrected grating point and its output information in the correction history information storage part 9. Consequently, a new correction value can be set by referring to the variation history up to the last time, so that the operation is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a color image processing system, and more particularly to an image processing method, an image processing apparatus, and a recording medium for reproducing more faithful colors.

[0002]

2. Description of the Related Art In recent years, when an image is output, color mismatch between devices (for example, a display device and an output device) has become a problem. Therefore, recently, information such as the color gamut of each device is stored in advance in a storage unit (profile), and when performing color conversion between devices, these profiles are referred to for more faithfulness. It is becoming possible to reproduce various colors (hereinafter, such a method is called color matching).

The above-mentioned "information such as the color gamut of each device" may take any form, but in the following embodiment, an ICC (Intenet) which is generally widely used is used.
An rColor Consortium color profile (hereinafter simply referred to as a profile) is used.

FIG. 13 shows a configuration example of a conventional color image processing system. In FIG. 13, the display device 1 is a display, the image input device 3 is a scanner or the like,
The output device 5 is a printer, and the operation device 8 is a keyboard or a pointing device for giving an instruction to the image processing system 7.

The image processing system 7 includes an information storage device,
A program for executing processing is configured by an information processing device, an input / output device, and the like, and is stored in an information storage device. The operator is configured to interact with the image processing system 7 through a user interface mounted on the screen of the display device 1.

[0006] Image input device 3, display device 1, output device 5
For each image, a profile (image input device profile 4, display device profile 2, output device profile 6) containing information such as a color reproduction range is provided. The image processing system 7 performs color conversion between devices. Then, the image input device profile 4, the display device profile 2, and the output device profile 6 are loaded into a storage device in the system 7, and color conversion is performed based on the loaded profiles, thereby realizing color matching. Therefore, if there are a plurality of image input devices 3 or output devices 5, there will be a plurality of device-profile pairs.

However, there is not always only one profile for the same device. If there are multiple profiles for the same device, the operator needs to specify the profile to be used. Conversely, it is not always necessary that one or more profiles exist for one device. For example,
When the set of the image input device 3 and the output device 5 to be used does not change every time, the profiles 4 and 6 may be integrally configured as profiles for performing conversion between the input device color space and the output device color space.

The display device profile 2 and the image input device profile 4 include a device-specific color space (for example, RGB)
Values, CMY values, CMYK values, etc.) to device-independent color spaces (eg, CIE-XYZ, CIE-L * a *)
b *. (Hereinafter simply referred to as XYZ and Lab, respectively). Conversely, the output device profile 6 performs conversion from a device-independent color space to a device-specific color space. For the sake of explanation, these profiles 2, 4, 6
Has a configuration provided separately from the image processing system 7, but may be incorporated in the image processing system 7.

FIG. 14 shows a specific configuration example of a printer profile that handles CMYK colors, and FIG. 15 shows a data flow at the time of printing. The color conversion tables 71 and 73 are configured by lookup tables,
The gamma correction units 72 and 74 have a plurality of 1-input / 1-output gamma curves (gamma characteristics), that is, each color (CMY).
K). It is not always necessary to use both the look-up table and the gamma curve.
For example, a configuration in which all necessary information is stored in the look-up table and the gamma curve is simply a straight line of out = in (= a straight line having a slope of 1 passing through the origin) can be used.

In the example shown in FIG. 14, since the output is CMYK color, the profile is a three-input / 4-output profile for performing Lab → CMYK conversion (or XYZ → CMYK conversion). The profile configuration of the other devices is the same. For example, the profile of an input device that handles RGB images is converted from RGB to Lab (or RG
B → XYZ conversion) is performed.

Here, Lab input is 8 bits each, CMY
If the K output is also 8 bits, C = f1 (L, a, b) M = f2 (L, a, b) Y = f3 (L, a, b) K = f4 (L, a, b) , “3 input / 1 output table” × 4 colors. Therefore, the output of the look-up table alone requires (256 数 3) * 4 (color) * 8 (bit) ≒ 540 Mb in the number of bits.
It also becomes it. In this case, the data amount is large and high-speed processing is difficult. For this reason, the configuration is such that the output is normally provided only for a limited number of input points. That is, an input range is determined in advance (for example, ICC-Profile).
Then, L = 0 to 100, a, b = −128 to +127
The input range is divided into a finite number. Then, the output values for the divided input points are configured as a table. That is, if each variable of the Lab is divided into, for example, eight (= 9 points), the output of the look-up table is (9） 3) * 4 (color) * 8 (bit), and the size is greatly reduced. be able to. If the profile has an output value table only for a limited number of input points (hereinafter, referred to as grid points), the size of the table can be reduced. For input data outside the grid points (non-grid points), the image processing system may obtain output data by interpolation calculation based on the adjacent grid point data. As the interpolation algorithm, for example, there is a four-point interpolation method.

[0012]

In spite of using the above-described color matching method, even when outputting colors within the color gamut of a printer, it is often difficult to faithfully reproduce colors in reality. Absent. This can be caused by
One factor is the accuracy of creating the profile itself.

Various solutions have been proposed for such a problem. For example, regarding the adjustment of the profile, see, for example, JP-A-8-237494 and 9-2.
There is a technique described in Japanese Patent No. 47484.

In each of the above-mentioned techniques, the grid point output value of the existing color conversion table is changed later, thereby realizing better color matching. However, in reality, it is rare that a satisfactory correction can be made in one operation. Moreover, the number of grid points to be corrected is often not small. In such a case, the operation of resetting an appropriate output value for a plurality of grid points many times becomes very complicated.

The present invention has been made in view of the above circumstances, and an object of the present invention is to store past histories and repeat the information obtained from the histories when the color conversion table is repeatedly corrected. An object of the present invention is to provide an image processing method, an image processing apparatus, and a recording medium that can use the image processing apparatus to more efficiently correct a color conversion table.

[0016]

In order to achieve the above object, according to the first aspect of the present invention, a device-dependent first color is used by using color conversion means describing the color reproduction characteristics of a color input / output device. An image processing method for mutually performing color conversion between a space and a device-independent second color space, wherein the color conversion means is modified so that a predetermined color of the input image of the color matches a predetermined color of the output image. In this case, the correction history information for the predetermined color is referred to.

According to the second aspect of the present invention, the color conversion means describing the color reproduction characteristics of the color input / output device is used to switch between the device-dependent first color space and the device-dependent second color space. An image processing method for mutually performing color conversion,
When the color conversion means is corrected so that a predetermined color of the color input image matches a predetermined color of the output image, correction history information on the predetermined color is referred to.

According to the third aspect of the present invention, the printer gamma characteristic of the printing unit is corrected so that the predetermined color of the predetermined image displayed on the display unit matches the predetermined color of the image printed by the printing unit. In the image processing method, when correcting the printer gamma characteristic, reference is made to correction history information of the printer gamma characteristic for the predetermined color.

According to a fourth aspect of the present invention, the correction history information is the number of corrections for the predetermined color.

According to a fifth aspect of the present invention, the correction history information is an average value of correction values accumulated for the predetermined color.

According to a sixth aspect of the present invention, the correction history information is a median of correction values accumulated for the predetermined color.

According to a seventh aspect of the present invention, the correction history information is a value obtained by weighting the correction values accumulated for the predetermined color in accordance with the history.

[0023] The invention according to claim 8 is characterized in that the correction history information is a value obtained by weighting correction values accumulated for the predetermined color in accordance with an appearance frequency.

According to a ninth aspect of the present invention, the corrected result is reflected on the history information and the color conversion means.

The invention according to claim 10 is characterized in that the corrected result is reflected on the history information and the printer gamma characteristic.

According to the eleventh aspect, means for displaying an image signal represented in a device-dependent first color space;
First color conversion means for converting an image signal represented in the device-dependent first color space into an image signal represented in a device-independent second color space; and
A second color conversion means for converting an image signal expressed in the color space of the first color space into a third color space dependent on the device, and printing the displayed image signal through the first and second color conversion means. Means for storing history information of color correction in the second color conversion means, and means for selecting the predetermined color when the displayed image does not match the predetermined color of the printed image. Referencing the storage means according to the selection;
It is characterized in that it comprises means for displaying history information of color correction for the predetermined color, and means for correcting the second color conversion means based on the history information.

According to the twelfth aspect of the present invention, a means for reading a color original and inputting it as an image signal represented in a device-dependent first color space, and an image represented in the device-dependent first color space First color conversion means for converting a signal into an image signal represented in a device-independent second color space, and converting the image signal represented in the device-independent second color space into a device-dependent first color space A second color conversion unit for converting the image signal into a color space, a unit for displaying the input image signal via the first and second color conversion units, and a color correction unit for correcting the color in the first color conversion unit. Means for storing history information, means for selecting the predetermined color when the color document and the displayed document image do not match, and referring to the storage means in accordance with the selection, the predetermined color Displays color correction history information for Means for, is characterized in that a means for modifying said first color conversion means based on the subsequent history information.

According to the thirteenth aspect of the present invention, a means for displaying a predetermined image, a means for printing the predetermined image, a first means for storing a printer gamma characteristic of the printing means, and a correction of the printer gamma characteristic Second means for storing history information, means for selecting the predetermined color when the displayed image and the printed image do not match, and the second storage means in response to the selection And means for displaying correction history information of the printer gamma characteristic for the predetermined color, and means for correcting the printer gamma characteristic of the first means based on the correction history information. I have.

In the invention according to claim 14, the correction history information includes the number of corrections of the predetermined color, the average value or the median of the correction values accumulated for the predetermined color, and the correction value accumulated for the predetermined color as a history or appearance frequency. The information is characterized by including information weighted according to.

According to the fifteenth aspect, a function of displaying an image signal represented in a device-dependent first color space;
A first color conversion function of converting an image signal represented in the device-dependent first color space into an image signal represented in a device-independent second color space; and a second device-independent second color space.
A second color conversion function for converting an image signal expressed in a color space into a device-dependent third color space, and printing the displayed image signal via the first and second color conversion functions A function of storing history information of color correction in the second color conversion function, and a function of selecting the predetermined color when the displayed image and the printed image do not match with each other. A computer which has a function of referring to the history information in accordance with the selection, a function of displaying history information of color correction for the predetermined color, and a function of correcting the second color conversion function based on the history information. The present invention is characterized in that it is a computer-readable recording medium on which a program for realizing the above is recorded.

According to the sixteenth aspect of the present invention, a function of reading a color original and inputting it as an image signal represented in a device-dependent first color space, and a function of reading an image represented in the device-dependent first color space. A first color conversion function of converting a signal into an image signal represented by a device-independent second color space; and a device-dependent first image conversion function of converting the image signal represented by the device-independent second color space into a device-dependent first color space. A second color conversion function for converting the input image signal into a color space, a function for displaying the input image signal via the first and second color conversion functions, and a color correction function for the first color conversion function. A function of storing history information, a function of selecting the predetermined color when a predetermined color of the color document and the displayed document image do not match, a function of referring to the history information according to the selection, History of color correction for a given color And displaying the broadcast is characterized by a computer-readable recording medium recording a program for implementing the function of modifying said first color conversion function based on the subsequent history information to the computer.

According to the seventeenth aspect, a function of displaying a predetermined image, a function of printing the predetermined image, a function of storing a printer gamma characteristic of the printing function, and correction history information of the printer gamma characteristic A function of storing a predetermined color of the displayed image and the printed image when the predetermined color does not match, a function of referring to the correction history information according to the selection, A computer-readable recording medium storing a program for causing a computer to implement a function of displaying correction history information of printer gamma characteristics for a predetermined color and a function of correcting the printer gamma characteristics based on the correction history information. It is characterized by having.

In the invention according to claim 18, as the correction history information, the number of corrections of the predetermined color, the average value or the median of the correction values accumulated for the predetermined color, and the correction values accumulated for the predetermined color are recorded as history or frequency of appearance. 17. Data recorded with a value weighted according to the following is recorded.
7. A computer-readable recording medium according to item 7.

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be specifically described below with reference to the drawings. FIG. 1 shows a system configuration diagram of an embodiment of the present invention. The difference from FIG. 13 is that a profile correction history information storage unit 9 and a profile correction unit 10 are added. Profile modification history information storage unit 9
Like the profile itself, it is desirable that the profile is constituted by a magnetic disk or a nonvolatile memory so that data is not lost even when the system power is turned off. In the following process,
At run time, color correction is performed after each profile is loaded into a storage device in the system.

(Embodiment 1) Embodiment 1 relates to correction of an output device profile. 2 to 5 show operation screens of the first embodiment, and FIG. 6 is a processing flowchart of the first embodiment. FIG. 2 shows a situation in which the test image 21 is compared with the printed matter 22 of the test image, and a color that does not match the two is selected from the images.

Hereinafter, for simplicity, it is assumed that the test image is in the RGB format (8 bits for each color) and is composed of colors within the color reproduction range of the printer used. The printer used is a printer that handles the CMYK color format (8 bits for each color), and the device-independent color space handled by the system adopts a Lab space. Further, the grid points of the color conversion table have 8 points for each Lab input variable.
Division (= 9 points), that is, 9/3 in total. Also, a solid patch image was assumed as the test image. However, the present embodiment is not necessarily limited to this.

The printed patch 22 is, for example,
There are a total of 90 patches, that is, 10 patches vertically, and the patches displayed on the operation screen in FIG. 2 are a total of 32 patches from the fourth to the seventh. The test image 21 is compared with the printed matter 22 while scrolling up, down, left and right.

Here, in order to correct the color of the display image, when a portion 31 of the display image whose color is to be corrected is selected by the pointer 8 (step 101), the screen shown in FIG. 3 is displayed. The screen includes (1) a pixel value 32 (R) of the current image corresponding to the selected pixel.
(GB value) (2) Lab value 33 obtained by converting (1) using display device profile 2 (3) CMYK output values 34 of grid point coordinates corresponding to (2) on output device profile 6 Is displayed.

The table in the output device profile 6 is
As described above, normally, only the output values on the grid points are provided. Therefore, (3) is the Lab obtained in (2).
What is necessary is just to comprise so that the output value of the grid point coordinate closest to a value may be displayed. Here, the operator can correct the CMYK output values at the grid point coordinates of (3) for each CMYK color. For example, as shown in FIG.
When 1 is selected (step 103), a screen as shown in FIG. 5 is displayed. That is, the profile correction unit 10 reads the information of the correction history information storage unit 9 and displays the past correction history information 51 on the C color output at the grid point on the screen (FIG. 5). In this display example, the number of corrections, the simple average value of the accumulated corrected values, the most frequently used value in the past history, the value weighted by the appearance frequency, and the value weighted by the history are displayed.

For example, when the history is as follows, the immediately preceding value: 196, the value before 193 times, the value before 3 times, 195 the value before 4 times, 197 the value before 5 times: 193 The value before 6 times: 195 The value before 7 times: 193 The value before 8 times: 200 The value before 9 times: 190 The value before 10 times: 220 The weighting based on the frequency of appearance is, for example, employed two or more times. For the value that exists, a method such as multiplying the frequency by a constant can be considered. For example, multiply the frequency by 2 and in this case (193 * 2 * 2 + 195 * 3 * 2 + 196 + 197 +
200 + 190 + 220) / (4 + 6 + 5) ≒ 196 is obtained (decimal point, rounded off).

Similarly, weighting by history means, for example,
Assuming that the last round is multiplied by 5, 2 or 3 times before, 3 or 3 times before, (196 * 5 + 193 * 3 + 195 + 197 + 193 +
195 + 193 + 200 + 190 + 220) / (5 + 3
+8) ≒ 196. In any of the above cases, another pattern may be used as the weighting pattern.

While referring to these past correction information,
The operator may set an output value that is considered to be optimal at the grid point (step 104). In the example of FIG. 5, C = 194 is set as the new value C. If necessary, the output value may be changed in a similar procedure for each ink color (CMYK).

The above procedure is repeated for the portion where the color is to be changed (step 106). After that, when the “end” button on the screen is pressed, the profile correction unit 10 additionally stores the corrected grid point and its output value information in the correction history information storage unit 9. Further, the profile correction unit 1
0 stores the changed grid point output value in the output device profile 6 (step 107).

Reprinting may be performed using the corrected output device profile thus completed (that is, by reloading the storage device in the image processing system). If the colors of the resulting print still do not match,
The same procedure may be repeatedly executed to sequentially modify the profile. In this case, a new correction value can be set while referring to the change history up to the previous time, so that the operation is simplified.

If the above operation is repeated a plurality of times, history information is accumulated to a certain extent at a plurality of grid points. In such a case, if only the correction policy is determined first (for example, “correct based on the average value of all past histories”), the output of the grid points in which the history information is accumulated is all May be automatically updated in accordance with the above and stored in the output device profile. By doing so, it is possible to greatly reduce the labor of the operator.

In the above-described embodiment, the correction history information storage unit 9 is provided separately from the profile. However, the correction history information may be stored in the profile itself and may be integrally formed. By doing so, it is possible to prevent the sets of the output device profile 6 and the correction history information storage unit 9 from being scattered, and to achieve an effect of facilitating management.

In the above embodiment, the profile is
This is an example of a printer profile that performs conversion from Lab to CMYK, but the present invention can be applied to other printer profiles. For example, as described above, when a set of an input device and an output device is determined, R
There may be a case where a profile that handles the direct conversion of GB → CMYK is used, and even in such a case, the technology according to the present invention can be applied.

(Embodiment 2) Embodiment 2 relates to correction of an input device profile. FIG. 7 shows an example of the operation screen of the second embodiment, and FIG. 8 shows a processing flowchart of the second embodiment. The configuration of the second embodiment is the same as that of the first embodiment.

Hereinafter, for simplicity, the image input by the image input device 3 is in RGB format (8 bits for each color), and the device-independent color space handled by the image processing system 7 is as follows.
It is assumed that a Lab space is used. However, embodiments are not necessarily limited to this.

The difference from the first embodiment is that the operation target profile is an RGB → Lab conversion profile.
The operation target is a point having a Lab value. First, a document is read by the image input device 3 to obtain image data. Next, in the same procedure as described in the first embodiment, the original is compared with the image on the display screen, and the output value (Lab) of the input device profile 4 is compared.
Value).

In FIG. 7, the color (RGB value) to be corrected is selected (step 201), and the Lab value obtained by converting the color with the input device profile 4 is displayed. As in the first embodiment, when the operator selects, for example, the grid point output value L with the pointer 8 (step 203), the profile correction unit 10 reads the correction history information on the selected grid point output value L from the storage unit 9, The information is displayed on the display device 1. The operator sets the corrected grid point output value L on the screen with reference to the history information (step 204). The same applies to other colors (step 206), and the profile correction unit 10 additionally stores the corrected grid point and its output value information in the correction history information storage unit 9 and makes further changes. The grid point output value (Lab value) is stored in the input device profile 4 (step 207).

The document thus read may be read by reloading the corrected input device profile thus completed into the system. If the obtained display color and the original still do not match, the same procedure may be repeated to correct the profile. In this case, a new correction value can be set while referring to the change history up to the previous time, so that the operation is also simplified.

Further, if the above operation is repeated a plurality of times, history information is accumulated to a certain extent at a plurality of grid points. In such a case, if only the correction policy is determined first (for example, “correct based on the average value of all past histories”), the output of the grid points in which the history information is accumulated is all May be automatically updated and stored in the input device profile. By doing so, it becomes possible to greatly reduce the operation of the operator.

In the above-described embodiment, the correction history information storage unit 9 is provided separately from the input device profile 4, but the correction history information is stored in the input device profile 4 itself and integrated. May be configured. By doing so, it is possible to prevent the sets of the input device profile 4 and the correction history information storage unit 9 from being scattered, and it is possible to easily manage.

(Embodiment 3) In Embodiment 3, a gamma curve in the output device profile (gamma correction section 72 in FIG. 14)
Related to the correction of. 9 to 11 show an operation screen of the third embodiment, and FIG. 12 shows a processing flowchart of the third embodiment. The configuration of the third embodiment uses the configuration of the first embodiment. FIG. 9 shows a situation in which the test image is compared with a print of the test image, and a color that does not match the two is selected from the image.

Hereinafter, for simplicity, it is assumed that the test image is composed of RGB (8 bits for each color) and a color within the color reproduction range of the printer used. The printer used is a printer that handles the CMYK color format (8 bits for each color), and the device-independent color space handled by the system adopts a Lab space. However, the embodiment is not necessarily limited to this example.

The gamma curve (gamma characteristic) in the output device profile 6 is a CMYK output printer in this example. = F4 (Kin), and the operator can change the gamma curve for each CMYK color.

In order to correct the color, a portion of the displayed image whose color is to be corrected is selected with the pointer 8 in the same manner as in the first embodiment (step 301), and the ink color to be corrected is specified (step 303). For example, when the C (cyan) color is selected, the screen of FIG. 9 is displayed.

Here, (1) the selected ink (any of CMYK), the input / output value corresponding to the selected point, (2) the numerical sequence of the gamma curve, and the curve (3) the correction history information are read and displayed. The past output value change information on the color is displayed.

In this example, as in the first embodiment, the number of corrections, the simple average of the accumulated corrected values, the most frequently used value in the past history, the value weighted by the appearance frequency, and the history are weighted. Each value is displayed.

While referring to these past correction information,
The operator may set an output value that seems to be optimal for the input value (step 304). That is, FIG.
In the “new output value” column of the numerical value sequence shown in FIG. A blank means that the value is not changed. Since the gamma curve takes a continuous input value unlike the grid point data, it is necessary to simultaneously edit the output values before and after the target point so that no inconsistency occurs depending on the edit target point. This example will be described with reference to FIGS.

For example, the output value 210 of the input value 196 is
11 (FIG. 10 (b)).
If the curve is changed to, the curve will not be monotonous ((a) in FIG. 10), and it is necessary to simultaneously edit the output values before and after the target point as shown in FIG. 10 (c).

For such a reason, in addition to the editing method using numerical values, when the editing target point 61 on the gamma curve is directly operated with a pointer as shown in FIG. Alternatively, an editing method that changes dynamically may be adopted. Here, an example is shown in which the output value is slightly lowered by operating the pointer downward. FIG.
The dotted line in (a) is the value before editing, and the solid line in FIG. 11 (b) is the value after editing. In this case, a spline function or the like can be used as a method of interpolating the values before and after. In this way, a more intuitive operation becomes possible.

The above procedure is repeated for the portion where the color is to be changed. Then, when the “end” button on the screen is pressed, the profile correction unit 10 additionally stores the corrected input point and its output value information in the correction history information unit 9,
Further, the corrected output value is stored in the gamma correction unit of the output device profile. Reprinting may be performed using the corrected output device profile thus completed. If the colors of the obtained prints do not yet match, the same procedure may be repeatedly executed to sequentially correct the profile. In that case, you can set a new correction value while referring to the correction history up to the previous time,
Operation becomes easy.

When the above operation is repeated a plurality of times, history information is accumulated to some extent. In such a case, if only the correction policy is determined first (for example, “correct based on the average of the history”), all the table outputs that store the history information are automatically updated according to the history. Of course, it is also possible to adopt a system configuration in which the data is stored in the output device profile. By doing so, it becomes possible to greatly reduce the operation of the operator.

In the above embodiment, the correction history information storage unit 9 is provided separately from the profile.
The correction history information may be stored in the profile itself to be integrally configured. By doing so, it is possible to prevent the sets of the output device profile 6 and the correction history information storage unit 9 from being scattered, and to achieve an effect of facilitating management.

In the above example, the printer profile is taken as an example of the gamma curve correction destination. However, the present invention can be applied to other devices.

The present invention is not limited to the above-described embodiment, but can be realized by software. When the present invention is implemented by software, a general-purpose computer system is prepared, and a recording medium such as a CD-ROM stores processing procedures and processing functions for performing color correction while referring to the correction history of the present invention, and history information. Etc. are recorded. In addition, the test image stored in the hard disk or the like is printed and displayed on the monitor, the color is corrected on the monitor according to the above-described processing procedure, and the corrected profile is stored in the hard disk or the like.

[0069]

As described above, according to the present invention, since the profile is corrected with reference to the stored correction history, the user can efficiently correct the color, and as a result, the screen can be corrected. Color shift between display and actual output,
In addition, the color shift between the screen display and the input document can be significantly reduced, and more accurate color reproduction is realized. Also,
Since the average value, median value, and the like are used as the accumulated history information, color correction can be performed more efficiently and accurately.

[Brief description of the drawings]

FIG. 1 shows a system configuration of an embodiment of the present invention.

FIG. 2 shows a test image and a print of the test image.

FIG. 3 shows a display screen when a color correction portion is selected.

FIG. 4 shows a screen when a cyan color is selected as a correction color.

FIG. 5 shows a screen displaying a correction history for a selected cyan color.

FIG. 6 shows a processing flowchart of the first embodiment.

FIG. 7 illustrates an example of an operation screen according to the second embodiment.

FIG. 8 shows a processing flowchart of the second embodiment.

FIG. 9 shows a screen when a cyan color is selected as a correction color in the third embodiment.

FIGS. 10A to 10C show an example of correcting an output value with respect to an input value.

FIGS. 11A and 11B show before and after correction of a gamma curve.

FIG. 12 shows a processing flowchart of a third embodiment.

FIG. 13 shows an example of a conventional system configuration.

FIG. 14 shows an example of an output device profile.

FIG. 15 shows a data flow during printing.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 display device 2 display device profile 3 image input device 4 input device profile 5 output device 6 output device profile 7 image processing system 8 operating device 9 profile correction history information storage unit 10 profile correction unit

Continued on the front page F term (reference) 5B021 AA02 AA19 CC06 EE01 LL05 NN19 5B057 AA11 BA02 CA01 CB01 CE11 CE17 CE18 5C077 LL19 MM27 MP08 PP15 PP31 PP32 PP36 PP42 PP46 PQ08 PQ18 PQ22 PQ23 RR19 SS07 HB LAB H11 LAB LB01 LB02 MA01 MA05 MA10 MA17 NA03 PA02 PA03 PA05

Claims (18)

[Claims] 1. A color conversion unit that describes color reproduction characteristics of a color input / output device, performs color conversion between a device-dependent first color space and a device-independent second color space. An image processing method to be performed, wherein when correcting the color conversion means so that a predetermined color of the input image of the color matches a predetermined color of the output image, reference is made to correction history information about the predetermined color. Processing method. 2. A color conversion unit that describes the color reproduction characteristics of a color input / output device and performs mutual color conversion between a device-dependent first color space and a device-dependent second color space. An image processing method, wherein when correcting the color conversion means so that a predetermined color of the color input image matches a predetermined color of the output image, reference is made to correction history information on the predetermined color. Method. 3. An image processing method for correcting a printer gamma characteristic of a printing means so that a predetermined color of a predetermined image displayed on a display means matches an image of the predetermined image printed by the printing means. An image processing method for correcting the printer gamma characteristic by referring to correction history information of the printer gamma characteristic for the predetermined color. 4. The image processing method according to claim 1, wherein the correction history information is the number of corrections for the predetermined color. 5. The image processing method according to claim 1, wherein the correction history information is an average value of correction values accumulated for the predetermined color. 6. The image processing method according to claim 1, wherein the correction history information is a median of correction values accumulated for the predetermined color. 7. The image processing method according to claim 1, wherein the correction history information is a value obtained by weighting correction values accumulated for the predetermined color in accordance with a history. 8. The image processing method according to claim 1, wherein the correction history information is a value obtained by weighting correction values accumulated for the predetermined color in accordance with an appearance frequency. 9. The image processing method according to claim 1, wherein the corrected result is reflected on the history information and the color conversion unit. 10. The image processing method according to claim 3, wherein the corrected result is reflected on the history information and the printer gamma characteristic. 11. A device for displaying an image signal represented in a device-dependent first color space, wherein said device-dependent first color space is displayed.
A first color conversion means for converting an image signal expressed in a second color space independent of the device into an image signal expressed in a second color space independent of the device. A second color conversion unit for converting an image signal into a third color space dependent on a device, a unit for printing the displayed image signal via the first and second color conversion units, Means for storing color correction history information in the color conversion means, means for selecting the predetermined color when the displayed image does not match the predetermined color of the printed image, Image processing, comprising: means for displaying history information of color correction for the predetermined color with reference to storage means; and means for correcting the second color conversion means based on the history information. apparatus. 12. A means for reading a color original and inputting it as an image signal represented in a device-dependent first color space, and a device-independent image signal represented in the device-dependent first color space. First color conversion means for converting an image signal represented in a second color space into an image signal represented in a second color space; and a first device-dependent image signal represented in the device-independent second color space.
A second color conversion unit for converting the image signal into a color space, a unit for displaying the input image signal via the first and second color conversion units, and a color correction unit for correcting the color in the first color conversion unit. Means for storing history information, means for selecting the predetermined color when the color document and the displayed document image do not match, and referring to the storage means in accordance with the selection, the predetermined color An image processing apparatus, comprising: means for displaying history information of color correction for (1), and means for correcting the first color conversion means based on the history information. 13. A means for displaying a predetermined image, means for printing the predetermined image, first means for storing printer gamma characteristics of the printing means, and means for storing correction history information of the printer gamma characteristics. Means for selecting the predetermined color when the predetermined color of the displayed image does not match the predetermined color of the printed image; and referring to the second storage means in accordance with the selection, An image processing apparatus comprising: means for displaying correction history information of a printer gamma characteristic for a color; and means for correcting the printer gamma characteristic of the first means based on the correction history information. 14. The correction history information includes a number of corrections of the predetermined color, an average value or a median of correction values stored for the predetermined color, and a value obtained by weighting correction values stored for the predetermined color according to a history or an appearance frequency. 14. The image processing device according to claim 11, wherein the information includes information. 15. A function for displaying an image signal represented in a device-dependent first color space, and a device-dependent first color space.
A first color conversion function of converting an image signal expressed in a color space of a second color space into an image signal expressed in a second color space independent of the device, and a second color space independent of the device. A second color conversion function of converting an image signal into a device-dependent third color space; a function of printing the displayed image signal via the first and second color conversion functions; A function of storing color correction history information in the color conversion function, a function of selecting the predetermined color when the predetermined color of the displayed image does not match the predetermined color of the printed image, and a function of selecting the predetermined color according to the selection. A program for causing a computer to realize a function of referring to history information, a function of displaying history information of color correction for the predetermined color, and a function of correcting the second color conversion function based on the history information. Recorded computer readable Recording medium. 16. A function of reading a color original and inputting it as an image signal represented in a device-dependent first color space, and a device-independent image signal represented in the device-dependent first color space. A first color conversion function of converting an image signal represented by a second color space into an image signal represented by a second color space, and a first device-dependent image signal represented by the device-independent second color space.
A second color conversion function for converting the input image signal into a color space, a function for displaying the input image signal via the first and second color conversion functions, and a color correction function for the first color conversion function. A function of storing history information, a function of selecting the predetermined color when a predetermined color of the color document and the displayed document image do not match, a function of referring to the history information according to the selection, A computer-readable recording medium storing a program for causing a computer to realize a function of displaying history information of color correction for a predetermined color and a function of correcting the first color conversion function based on the history information. 17. A function of displaying a predetermined image, a function of printing the predetermined image, a function of storing a printer gamma characteristic of the function of printing, a function of storing correction history information of the printer gamma characteristic, A function of selecting the predetermined color when the predetermined color of the displayed image does not match the predetermined color of the printed image; a function of referring to the correction history information in accordance with the selection; and a printer gamma for the predetermined color A computer-readable recording medium storing a program for causing a computer to implement a function of displaying characteristic correction history information and a function of correcting the printer gamma characteristic based on the correction history information. 18. The correction history information includes a number of corrections of the predetermined color, an average value or a median of correction values stored for the predetermined color, and a value obtained by weighting correction values stored for the predetermined color according to a history or an appearance frequency. 18. The computer-readable recording medium according to claim 15, 16 or 17, which records data including: