JP2005196472A - Color information processing device, method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means which converts a color solid in a certain color system obtained by gamut mapping to a color solid in another color system with a simple operation to display the color solid. <P>SOLUTION: In a hierarchical tree window 903, nodes 908 and 911 which each correspond to a window 901 corresponding to a first color system displayed and a window 902 corresponding to a second color system, respectively, and nodes corresponding to color solids 904-907 of each of the color systems which each are displayed in each window and obtained by gamut mapping are displayed in a tree structure. When an operator selects an object corresponding to a color solid, drags it and drops it on an object corresponding to one of the windows, the moved color solid is coordinate converted to the color system of the window to which the drop is executed and displayed on the window as a color solid. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a color information processing apparatus that displays sample points in a coordinate system corresponding to a color system, for example, to perform color distribution analysis in a computer or the like.

As a color reproduction technology for perceptual matching of images between media with different color gamuts, such as printers and display devices, there is a gamut mapping technology that associates one color gamut with another color gamut in a uniform color system. . In order to qualitatively and intuitively determine the gamut mapping technique, a color information processing apparatus that can display color distribution information in a pseudo three-dimensional manner in various display forms has been proposed (see Patent Document 1). The color information processing apparatus disclosed in Patent Document 1 displays a color solid displayed on a pseudo three-dimensional display window in various display forms by combining a hue range, a grid range, and a display surface of the color solid according to a user instruction. It can be done. In such a color information processing apparatus, a color solid composed of reference color system sample points is three-dimensionally displayed in a desired color system color space. This three-dimensional display is pseudo, and is realized by displaying a color solid in a virtual color space as a two-dimensional image projected in a desired direction. For this reason, it is sometimes called a pseudo three-dimensional display. In this specification, a color solid in a three-dimensional color space may be referred to as a “three-dimensional object” by comparing it with a tangible object in a real space.
JP 2002-222432 A

  In recent years, with the advent of various media and the advancement of color reproduction, there is a need for a color information processing apparatus that can compare and evaluate gamut mapping in a plurality of color systems. However, the conventional color information processing apparatus cannot appropriately compare and evaluate three-dimensional objects (that is, color solids) gamut-mapped in different color systems. Specifically, a color solid that is gamut mapped in the L * a * b * color system and a color solid that is gamut mapped in the L * u * v * color system can be displayed three-dimensionally on the same display window. could not. In addition, for example, for the purpose of comparing the results obtained by gamut mapping the colors (device colors) output by one medium with a plurality of color systems, the color solids in a certain color space can be compared with other colors. A simple user interface for converting to a color space has not been provided.

  The present invention has been made in view of the above-described conventional example, and by converting a color solid obtained by gamut mapping in a predetermined color system into a color solid in the color space of another color system, the color space is obtained. It is an object of the present invention to provide a color information processing apparatus, method, and program that can be displayed as a color solid.

  It is another object of the present invention to provide a color information processing apparatus, method, and program capable of comparing color solids obtained by gamut mapping in different color systems by displaying them in a common color space. .

  It is another object of the present invention to provide a color information processing apparatus, method, and program that can provide a simple user interface for converting from one color system color space to another color system color space. .

  In order to achieve the above object, the present invention has the following configuration.

A color information processing apparatus,
Storage means for storing color distribution information in which sample point sets in the first color system are represented by coordinate values in the second color system;
First display means for displaying, on the first display window, the sample point set as a color solid in the color space of the second color system based on the color distribution information;
In response to an instruction to display the sample point set displayed in the first display window in a second display window corresponding to a third color system different from the second color system, the second Conversion means for converting the coordinate value in the color system to coordinate values in the third color system;
Based on the coordinate values in the third color system converted by the conversion means, the sample point set is displayed in the second display window as a color solid in the color space of the third color system. 2 display means.

More preferably, an operation means for selecting a color solid displayed on the display window and moving to a display window corresponding to a desired color system, a display window for each color system, and the color distribution information Tree display means for creating a tree information indicating the relationship, and displaying a tree having a node corresponding to the display window and a node corresponding to the color distribution information based on the tree information;
The instruction to display the sample point set displayed in the first display window in the second display window is the color solid displayed in the display window or the color distribution displayed in the tree by the operation means. This is done by selecting a node of information and moving to the node of the display window corresponding to the color system displayed in the display window or the tree as the desired position.

  More preferably, the first color system is one of an RGB color system, a CMY color system, an XYZ color system, an L * u * v * color system, and an L * a * b * color system. It is.

  More preferably, the second color system is any one of an XYZ color system, an L * u * v * color system, and an L * a * b * color system.

  More preferably, the sample points belonging to the sample point set are regularly arranged in a grid pattern in the first color system.

  More preferably, when the sample point set is displayed as the color solid, the color of the surface of the color solid is controlled according to the color coordinates of the sample points in the first color system.

  More preferably, when displaying the sample point set as the color solid, the color of the surface of the color solid is controlled according to the color coordinates in the second color system.

  More preferably, the color distribution information performs gamut mapping on the sample points in the first color system, and obtains color coordinate values that the sample points can take in the second color system. Is obtained.

  More preferably, the color distribution information performs perceptual adaptation processing on the sample points in the first color system, and obtains color coordinate values that can be taken by the sample points in the second color system. Can be obtained.

  According to the present invention, a window representing a color space for each color system is displayed, and a color solid displayed in a certain color system window is selected and moved by an operator to another color system window. It is possible to provide a user interface with high operability in which the color system can be converted by an intuitive operation of moving to the position. Since the coordinates of each sample point of the color solid moved by the user interface are converted from the source color system to the destination color system, they are obtained by gamut mapping in one color system. A color solid can be easily converted into another color system. Therefore, it is possible to easily evaluate the gamut mapping technique by comparing the color reproduction ranges for each medium or by comparing a plurality of color solids obtained by gamut mapping.

  Hereinafter, a color information processing apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.

<Configuration of color information processing apparatus>
FIG. 3 is a block diagram showing the system configuration of the color information processing apparatus of this embodiment. In FIG. 3, the CPU 301 uses a main memory 303 such as a RAM as a work area, programs and data stored in the ROM 302 and the HDD 305, and a user's input via the keyboard 309, mouse 310, and keyboard / mouse controller 308. In accordance with the instruction, each component connected via the bus 313 is controlled, and various processes including processes to be described later are executed. The HDD 305 describes processing according to the processing procedure shown in FIG. 4 described later, a processing procedure program according to the flowchart of FIG. 10, the color distribution information 3051 illustrated in FIG. 2, and the like. The program and data are loaded into the main memory 310 and the program is executed. The HDD I / F 304 provides a general-purpose interface such as SCSI or ATA for connecting the HDD 305. The graphic accelerator 306 provides an interface for displaying an image on the color monitor 307. The graphic accelerator 306 preferably has a function for speeding up the window display by a bit block transfer function or the like and realizing a high-speed three-dimensional display. As an interface for connecting the hard disk, any interface may be used as long as processing described later can be executed. Further, an IO interface 311 such as USB or IEEE1394 is provided, and color distribution information can be input via the IO interface 311.

<Color distribution information>
Next, color distribution information created in advance as input data to the system will be described. The color distribution information is information obtained by gamut mapping. Specifically, for example, a color patch that is a sample color is output by a printer or a display, the color is measured by a colorimeter (not shown), and is digitized as a vector in a color space of a desired color system. .

  FIG. 1 is a diagram showing an example of the sample color. FIG. 1 schematically shows lattice points in the color space of the RGB color system. Each grid point is a sample color. In FIG. 1, the number of lattice points is “6” for the R, G, and B axes. That is, if each color component is expressed in 256 levels from 0 to 255, the value of each color component at the grid point is 0, 51, 102, 153, 204, 255. Therefore, the points where any one of these values is used for each color component of (R, G, B) is the lattice point in FIG. FIG. 1 shows the sample points corresponding to black (K), red (R), green (G), blue (B), yellow (Y), magenta (M), cyan (C) and white (W). The RGB coordinates and the grid coordinates of the sample point by the grid number are shown. The grid number indicates the coordinate component of each grid point with grid point numbers 0 to 5.

  Such a sample color (also referred to as a sample point) is determined in advance, and a color patch having a color component based on the RGB color system as an input value is output by a desired output device such as a printer display. That is, the output color patch is a sample when the color corresponding to each lattice point in FIG. 1 is actually output by the output device. This output processing may be performed in a system separate from the system of FIG. The color patch is measured with a colorimeter to obtain color distribution information as shown in FIG.

  The color distribution information includes each grid point (that is, sample color) in the RGB color system and, for example, one of the L * a * b * color system, the L * u * v * color system, or the XYZ color system. Corresponding to coordinate values in the color space of the color system. For example, data describing color distribution information is as shown in FIG. FIG. 2 shows an example in which a grid point obtained by dividing each color component into eight is used as a sample color in a color space in which each RGB color component is expressed by 256 gradations. That is, for each color component, points that are 0, 32, 64, 96, 128, 160, 192, 224, and 255 are set as lattice points. Therefore, the grid number is 0-8. This color distribution information is measured for the color patch in the L * a * b * color system, and the expression by the RGB color system is associated with the expression by the L * a * b * color system.

  FIG. 2A is an example in which the color distribution information is described in XML, and the sample color is indicated in the RGB color system by the <source> element. The <source> element further includes a <channel name => element indicating each color component, in which the grid number for each color component is defined by the <index> element. In FIG. 2, for example, for the R component, there is a description of <index> 0 </ index> in the first index, and <index> 32 </ index> in the second index. Is the grid number 0 and the value 32 is the grid number 1.

  Then, by the <destination> element and the <lab> element included therein, the color component of the L * a * b * color system obtained as a result of the measurement is obtained for each grid coordinate in the RGB color system of the sample point. A value is described. For example, the L * a * b * color system coordinate values corresponding to the grid coordinates (0, 0, 0) are (L *, a *, b *) = (11.75, 1.14, −9.63). ) Is indicated by <l> element, <a> element, and <b> element in the <lab r = “0” g = “0” b = “0”> element.

  If the color distribution information is a table in which the coordinates of the sample points in the RGB color system as shown in FIG. 2B are associated with the coordinates of the L * a * b * color system, FIG. Of course, the XML format is not required.

<Processing operation of color information processing apparatus>
FIG. 4 is a diagram of a processing procedure representing color information display processing by the color information processing apparatus (particularly the CPU 302) of FIG. When activated, the color information processing apparatus performs initialization such as securing a working heap memory (S401). Subsequently, color distribution information as illustrated in FIG. 2 is read (S402). At this time, color distribution information created in advance is stored in the hard disk 305 and read into the memory 303. Alternatively, the color distribution information can be read into the memory 303 via the IO interface 311 or a network interface (not shown).

  Next, based on the read color distribution information, color solid information (three-dimensional object information) is generated (S403). Based on the generated color solid information, the color solid is displayed in a three-dimensional display window (pseudo three-dimensional display window) on the color monitor 307 (S404). Next, the relationship between the color three-dimensional information and the pseudo three-dimensional display window is configured in a tree hierarchy (S405) and displayed in a hierarchy tree window on the color monitor 307 (S406). Thereafter, the state waits for an event (S407). When an event is notified, appropriate processing is performed according to each event. Specifically, if the “end” item is specified from the menu field of the three-dimensional display window, the color information display process is ended. If an operation for displaying new color distribution information as a color solid is performed, the designated color distribution information is read (S10). If an operation to move to a 3D display window of another color system is performed by specifying the color 3D displayed in the 3D display window or the color 3D information displayed in the tree, depending on the operation, The color solid is moved to the designated destination color space, and coordinate conversion processing is performed (S408, S409).

  Next, the main steps of FIG. 4 will be described in detail.

(Read color distribution information (S402))
If the color distribution information is the location (Windows (registered trademark)) of the color distribution information file (data file illustrated in FIG. 2) input by the user from the keyboard 309 or the mouse 310, the path information and file name of the folder to which the file belongs. ). If the input location information is correct, the specified color distribution information file is read. If it is not correct, an error or the like is displayed by the operating system processing. The specified location may be a folder on a hard disk or a folder on an external device via a network or the like. The read color distribution information is stored in the main memory 303.

(Generation of color solid information (S403))
In this process, color solid information having the data structure shown in FIG. 5 is generated from the read color distribution information and stored in the memory 303 or the hard disk 305. That is, the generated color solid information includes the coordinate value 501 of the sample point in the first color system, the coordinate value 502 of the second color system corresponding to the sample point in the first color system, the second It includes a color system 503, a reference destination 504 of a displayed three-dimensional display window, and form information 505. Here, three items of the coordinate value 501 of the sample point in the first color system, the coordinate value 502 of the second color system corresponding to the sample point in the first color system, and the second color system 503 are shown. Is included in the color distribution information. For example, when the color distribution information is defined in a format as shown in FIG. 2A, a grid (defined by the <index> element) defined in the channel element included in the <source> element is defined. A sample point in the first color system is represented. Then, from the <destination> element, the second color system defined as the mapping destination of the gamut mapping by the definition of the second color system defined, for example, the <lab r = ...> element in FIG. Can be obtained. FIG. 2A shows that the second color system is L * a * b * by defining a tag <lab r = ...>. Further, the coordinate values of the sample points in the second color system L * a * b * are indicated by the <l>, <a>, and <b> elements in the <lab r =...> Element. For this reason, in the generation of the color solid information, the coordinate value 501 of the sample point in the first color system, the coordinate value 502 of the second color system corresponding to the sample point in the first color system, the second As the information representing the color system 503, color distribution information 3051 may be taken in.

  For the reference destination 504 of the displayed 3D display window, the 3D display window of the second color system is initially selected. If this window does not exist, a three-dimensional display window is newly generated at this time, and the generated window is recorded in the memory as the reference destination 504 of the color solid information. The reference destination 504 of the three-dimensional display window is referred to when the color solid is displayed, and the color solid relating to the color solid information is displayed in the reference destination window.

  The form information 505 indicates how to display the color solid. As the form information 505, for example, a value input by an operator is recorded. The value to be entered is, for example, a value that specifies wireframe display, a value that specifies solid display (hidden surface removal), or a value that specifies the display method for displaying the solid display surface with a color corresponding to the position. and so on. In the display of the color solid, the color solid can be displayed by referring to the form information and the display method corresponding to the value. However, in the present embodiment, the form information is not referred to, and the color solid is displayed as an object having a color corresponding to the position on the surface of the solid display.

(Color solid display (S404))
In the display step, a color solid is displayed in the pseudo three-dimensional display window. The color solid is configured by plotting sample points represented by the coordinate values of the second color system in the color space of the second color system. As described above, in this embodiment, the color solid is displayed as a solid. For this purpose, among the sample points in the first color system, the second color of the points included in the maximum lattice region surface (that is, each surface of the cube including the color space that can be expressed in FIG. 1). The coordinate values of the system are plotted in the color space of the second color system, a wire frame is created to form the surface, and this is projected onto the display surface to create an image to be displayed. Then, the image is displayed in a three-dimensional display window. Of course, a wire frame can be displayed, and the sample points inside the color solid can also be displayed in the color space of the second color system.

  Here, when displaying the surface of the color solid, the minimum quadrangle (minimum grid) formed by each grid point on the surface of the maximum grid area in the first color system is used by combining two triangles each. Can be displayed. That is, the sample points of the first color system are included in a cube having vertexes at the coordinate points of WRGBYMCK as shown in FIG. Even if this is expressed in the color space of the second color system, the four points constituting the minimum grid on the surface of the maximum grid area in FIG. 1 are not necessarily located on the same plane. For this reason, in the second color system, the minimum grid is displayed by being divided into two triangles. This is the same when displaying a color solid in a color system other than the first color system.

  This schematic diagram is shown in FIG. In FIG. 6, a rectangular region 600 is a minimum lattice formed by each lattice point. When the four points constituting the rectangular area 600 deviate from one plane, it is expressed by a combination of two triangles. In FIG. 6, the rectangular region 600 can be divided into two combinations, a combination of two triangles divided by a line 601 and a combination of two triangles divided by a line 602. This is the same when each lattice point is not on one plane. Therefore, when dividing a quadrangle composed of sample points into a triangle, a division method is selected which maximizes the volume of the color solid of the second color system. That is, the volume of a tetrahedron formed by four points that are located on the surface of the color solid and are not on the same plane is configured from the sample points so as to be included in the color solid of the second color system. The quadrilateral is divided into two triangles.

  As described above, the data of the color solid in the color space of the second color system is created and temporarily stored in the memory, and the image data obtained by projecting the color solid on the display surface is created. Save to. The created projection image is displayed on the pseudo three-dimensional display window by the color monitor 307. When displaying, it is desirable to display the coordinate axes of the color system together.

(Create tree structure (S405))
In the tree structure creation step, tree structure data composed of all color solid nodes and nodes indicating pseudo three-dimensional display windows is created, stored in the memory, and displayed on the color monitor 307 together. The tree structure is configured such that a node indicating a color solid displayed in the pseudo three-dimensional display window belongs as a child node of the node indicating the pseudo three-dimensional display window. An example of the tree structure is shown in FIG. In the example of FIG. 7, two windows, a three-dimensional display window 1 (710) and a three-dimensional display window 2 (720), are included, and color solid information 1 (711), 2 (712) and color solid, respectively. Information 3 (721) and 4 (722) belong. In a state where the color distribution information is read for the first time, the color solid is displayed only for the second color system included in the color distribution information. Therefore, it is sufficient that the pseudo three-dimensional window is created and displayed only for the second color system, and the tree structure is the same. However, as described later, the user can perform an operation of moving the color solid between the pseudo three-dimensional display windows, and the color system conversion by the operation is also a feature of the present invention. Therefore, even for a color system that does not belong to color solid information at all, any color system that can be converted (that is, can be displayed) by the color processing system of the present embodiment is compatible with the three-dimensional display window of the color system. The node to be added is added to the tree structure. Although it is not necessary to display a color system pseudo three-dimensional display window to which color solid information does not belong at all, it may be created and displayed for convenience of operation.

  In the example of FIG. 5, the second color system included in the color solid information is L * a * b *. Therefore, when the procedure of FIG. 4 is executed with the color solid information as an input, in addition to the node of the three-dimensional display window corresponding to the second color system L * a * b *, L * a * b * Tree structure data including nodes of a 3D display window corresponding to the L * u * v * color system and the XYZ color system that can be converted from the color system is created. These convertible color systems are determined in advance. The tree structure data includes, for example, information indicating correspondence between nodes and objects (three-dimensional display window, color solid, color system), information indicating inclusion relations between nodes, and names of the nodes. Each node is preferably given a name that allows the operator to recognize the color system.

  When a tree node corresponding to the pseudo 3D display window is newly created, if there is a corresponding pseudo 3D display window, information indicating the relationship with the window and information on the color system indicated by the node are displayed. , Save it in the memory or hard disk in association with the node. The information indicating this association is desirably information that can identify a related party from any of the associated information. Thereby, when a node is specified, a color system corresponding to the node or a pseudo three-dimensional display window can be specified.

  When a pseudo three-dimensional display window is created and displayed, information indicating the correspondence between the displayed pseudo three-dimensional display window and the color system represented by the pseudo three-dimensional display window is created. Save it to the memory or hard disk in association. Thereby, when the pseudo 3D display window is specified, the color system corresponding to the pseudo 3D display window can be specified.

  That is, the tree node, the pseudo three-dimensional display window, and the color solid are stored together with information for specifying each color system and information indicating the correspondence between them.

(Hierarchical tree display (S406))
In the hierarchical tree display step, a tree image is displayed in a hierarchical tree window based on the tree structure data created by the tree structure creation step. An example of a hierarchical tree window is shown in FIG. In the hierarchical tree window 801, nodes indicating all the color solids and the pseudo three-dimensional display window are hierarchically displayed with their inclusion relations visualized by lines. Each node is given its name.

  The hierarchical tree window 801 can be improved in operability by adding a user interface such as a menu for selecting a three-dimensional object with the keyboard 309 or the mouse 310 and displaying the front of the pseudo three-dimensional display window. In addition, a user interface that allows a desired operation to be selected from the context menu 802 can be displayed.

(Process according to color solid movement operation (S408))
In FIG. 9, two pseudo three-dimensional display windows 901 and 902 are created and displayed by the processing up to step S408, and two sets of color distribution information in which each color system is the second color system are read. 3 is an example of a screen 900 displayed on the color monitor 307. The pseudo three-dimensional display window 901 is a window representing a color space of the L * a * b * color system, and color solids 904 and 905 are displayed therein. The pseudo three-dimensional display window 902 is a window representing a color space of the L * u * v * color system, in which color solids 906 and 907 are displayed. In the hierarchical tree window 903, nodes 909 and 910 indicating the color solids 904 and 905 are displayed below the node 908 indicating the pseudo 3D display window 901, and the node 911 indicating the pseudo 3D display window 902 is displayed. Below, nodes 912 and 913 indicating the color solids 906 and 907 are displayed.

  Here, when an operation for moving a color solid displayed in a certain window to a window of another color system is performed, in step S408, the color solid is displayed again in the destination color system. For example, when the operator selects a color solid 904 displayed in the pseudo 3D display window 901 using a keyboard or a pointing device and moves it to another pseudo 3D display window 902 by dragging and dropping operations, the movement is performed. In accordance with the operation, the color solid 904 moved by the destination color system is displayed again.

Next, details of the processing in step S408 will be described with reference to FIG. Before that, a method of moving a color solid in the user interface will be described. The color information processing apparatus according to the present embodiment provides the following four methods as a user interface for instructing movement.
1: Drag the node indicating the color solid displayed in the hierarchical tree window and drop it on the node indicating the pseudo three-dimensional display window displayed in the hierarchical tree window.
2: Drag the node indicating the color solid displayed in the hierarchical tree window and drop it on the pseudo three-dimensional display window.
3: Drag the color solid displayed in the pseudo 3D display window and drop it on the pseudo 3D display window.
4: Drag the color solid displayed in the pseudo 3D display window and drop it on the node indicating the pseudo 3D display window displayed in the hierarchical tree window.

  In this way, if an operation for moving the image object corresponding to the color solid to be moved to the image object corresponding to the movement destination window is performed, it can be determined that the operation is a color solid movement operation.

  Next, details of the processing in step S408 when the color solid moving operation is performed by the above method will be described with reference to FIG. 10 illustrates an example in which an operation for moving the color solid 904 illustrated in FIG. 9 to the window 902 is performed. By replacing the color solid 904 with the color solid to be moved and the pseudo three-dimensional display window 902 with the pseudo three-dimensional display window of the movement destination, it can be applied to general processing.

  In step S1001, the second color system is acquired from the color solid information corresponding to the color solid 904. Here, the second color system is the L * u * v * color system. In step S1002, the color system of the destination pseudo 3D display window 902 is acquired. Here, the L * a * b * color system is used.

  In step S1003, the second color system of the color solid information to be moved is compared with the color system of the destination pseudo 3D display window. In step S1004, the comparison result is determined. If the two color systems are equal, the process proceeds to the three-dimensional display step (S1008). If the two color systems are different, the process proceeds to step S1005. In the case of an operation for moving the color solid 904 to the pseudo three-dimensional display window 902, since the color system is different, the process proceeds to step S1005.

  In step S1005, the coordinate value in the second color system of the sample point is acquired from the color solid information corresponding to the color solid to be moved. Here, the coordinate value of each sample point expressed in the L * u * v * color system is read into the memory.

  In step S1006, the coordinate values in the second color system read into the memory in step S1005 are displayed in the pseudo three-dimensional display of the movement destination using any one or combination of conversion formulas (1) to (4) described later. Convert to the window color system. Here, the coordinate value in the L * u * v * color system is converted into the coordinate value in the XYZ color system using the conversion formula (4), and the coordinate value in the XYZ color system is converted into the conversion formula (1). Are converted into coordinate values in the L * a * b * color system. The coordinate values in the L * a * b * color system obtained by the conversion are stored in a memory or a hard disk in association with the color solid information. It can also be incorporated into the color solid information as part of the color solid information. Further, when coordinate conversion is performed in a plurality of stages as in this example, the coordinate values in the intermediate stage may be cached. Thus, when processing using the intermediate value is performed, the processing speed can be increased by reusing the cached data.

  In step S1007, a destination pseudo 3D display window (in this example, a pseudo 3D display window 902) is displayed as the “reference destination of a displayed pseudo 3D display window” 504 of color solid information corresponding to the color solid to be moved. Set the association information. At this stage, the moved pseudo 3D display window and the coordinate value of the sample point after movement are associated with each other from the color solid information of the color solid to be moved.

  In step S1008, the color solid after conversion determined by the coordinate values converted in step S1006 is displayed in the pseudo 3D display window indicated by “reference destination of displayed pseudo 3D display window” 504.

  With the above procedure, a color solid obtained by gamut mapping in one color system can be displayed in another color system by an intuitive operation of moving the color solid. For this reason, comparison of the color reproduction ranges of different output devices can be performed with a very simple operation.

  Next, some examples of coordinate transformation used in step S1006 are shown. Conversion from the XYZ color system to the L * a * b * color system uses the following conversion formula (1).

However, Xn, Yn, Zn are X, Y, Z values by the standard light of the perfect diffuse reflection surface, and here, D50 white point is used as a reference,
Xn = 96.43, Yn = 100.0, Zn = 82.51
And

  The XYZ color system coordinate value can be obtained from the L * a * b * color system coordinate value by the inverse conversion formula (2).

  The conversion formula (3) from the XYZ color system to the L * u * v * color system is defined as follows.

However, un 'and vn' are values obtained by substituting Xn, Yn and Zn into the above equation,
un '= 0.2092, vn' = 0.4881
It is.

  The XYZ color system coordinate value can be obtained from the L * u * v * color system coordinate value by the inverse conversion formula (4).

By the above conversion formula, the XYZ color system, the L * a * b * color system, and the L * u * v * color system can be converted to each other.
As described above, according to the color information processing apparatus (or computer system) of this embodiment, a color solid obtained by gamut mapping in one color system can be obtained by an intuitive operation of moving a color solid. It can be displayed by other color systems. For this reason, comparison of the color reproduction ranges of different output devices can be performed with a very simple operation.

It is a figure which shows typically the lattice point corresponding to the sample color in RGB color system. It is a figure which shows an example of the file which described color distribution information. It is a block diagram which shows the system configuration | structure of the color information processing apparatus of embodiment. It is a figure showing the processing operation of a color information processing apparatus. It is a figure which shows the data structure of three-dimensional object information and a pseudo | simulation three-dimensional display window. It is a figure which shows the minimum quadrangle formed by each lattice point. It is a figure which shows an example of the tree structure created by the tree structure creation means. It is a figure which shows an example of a hierarchy tree window. It is a figure which shows an example of the screen displayed on a monitor. It is a flowchart figure which shows the process performed by a movement instruction | indication means.

Claims (11)

Storage means for storing color distribution information in which sample point sets in the first color system are represented by coordinate values in the second color system;
First display means for displaying, on the first display window, the sample point set as a color solid in the color space of the second color system based on the color distribution information;
In response to an instruction to display the sample point set displayed in the first display window in a second display window corresponding to a third color system different from the second color system, the second Conversion means for converting the coordinate value in the color system to coordinate values in the third color system;
Based on the coordinate values in the third color system converted by the conversion means, the sample point set is displayed in the second display window as a color solid in the color space of the third color system. A color information processing apparatus comprising: 2 display means. An operation means for selecting a color solid displayed on the display window and moving it to a display window corresponding to a desired color system, and a tree showing the relationship between the display window for each color system and the color distribution information Tree display means for generating information and displaying a tree having a node corresponding to the display window and a node corresponding to the color distribution information based on the tree information;
The instruction to display the sample point set displayed in the first display window in the second display window is the color solid displayed in the display window or the color distribution displayed in the tree by the operation means. The color according to claim 1, wherein the information is selected by selecting a node of information and moving to a node of a display window corresponding to a color system displayed in the display window or the tree as the desired position. Information processing device.   The first color system is one of RGB color system, CMY color system, XYZ color system, L * u * v * color system, and L * a * b * color system. The color information processing apparatus according to claim 1, wherein:   The second color system is one of an XYZ color system, an L * u * v * color system, and an L * a * b * color system. The described color information processing apparatus.   4. The color information processing apparatus according to claim 1, wherein the sample points belonging to the sample point set are regularly arranged in a grid pattern in the first color system.   2. The display device according to claim 1, wherein when the sample point set is displayed as the color solid, the color of the surface of the color solid is controlled according to the color coordinate of the sample point in the first color system. Color information processing device.   2. The color information processing according to claim 1, wherein when the sample point set is displayed as the color solid, the color of the surface of the color solid is controlled according to color coordinates in the second color system. apparatus.   The color distribution information is obtained by performing gamut mapping on the sample points in the first color system and obtaining color coordinate values that the sample points can take in the second color system. The color information processing apparatus according to claim 1.   The color distribution information is obtained by performing a perceptual adaptation process on the sample points in the first color system and obtaining color coordinate values that can be taken by the sample points in the second color system. The color information processing apparatus according to claim 1. Based on the color distribution information stored in the memory in which the sample point set in the first color system is represented by the coordinate values in the second color system, the sample point set is converted into the second color system. A first display step of displaying in a first display window as a color solid in a color space;
In response to an instruction to display the sample point set displayed in the first display window in a second display window corresponding to a third color system different from the second color system, the memory is stored in the memory. A conversion step of converting the stored coordinate values in the second color system into coordinate values in the third color system;
Based on the coordinate values in the third color system converted by the conversion step, the sample point set is displayed in the second display window as a color solid in the color space of the third color system. A color information processing method comprising: 2 display steps. Based on the color distribution information stored in the memory in which the sample point set in the first color system is represented by the coordinate values in the second color system, the sample point set is converted into the second color system. First display means for displaying in a first display window as a color solid in a color space;
In response to an instruction to display the sample point set displayed in the first display window in a second display window corresponding to a third color system different from the second color system, the second Conversion means for converting the coordinate value in the color system to coordinate values in the third color system;
Based on the coordinate values in the third color system converted by the conversion means, the sample point set is displayed in the second display window as a color solid in the color space of the third color system. (2) A program for realizing the display means by a computer.

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