JP2017146387A - Information processing apparatus, control method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information processing apparatus that displays, in a recognizable manner, what color of a target device is reproduced in what way in a device to be adjusted.SOLUTION: An information processing apparatus according to the present invention calculates a difference in color between a color signal in a L*a*b* color space where a sampled signal value of an sRGB color space is converted by using color characteristics of a target device, and a color signal in a L*a*b* color space where a sampled signal value of the sRGB color space is converted by using color characteristics of an adjustment device, and displays a boundary line of a color reproduction area where the difference in color becomes equal to or larger than a threshold.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an information processing apparatus, a control method, and a program.

  In recent years, image processing apparatuses have become widespread, and replacement of old models that have passed the service life from new models to new models has been carried out, and new image processing apparatuses have been purchased in accordance with changes in the scale of offices. In a printing workflow in a user's office, there is a demand that the user wants to inherit the color of the device (image processing apparatus) before the replacement or at the time of replacement or purchase. Hereinafter, a device that wants to inherit a color, such as a device before replacement or a handheld device, is referred to as a target device, and a device that inherits color, such as a device after replacement or a purchased device, is referred to as an adjustment target device.

  A color management system (CMS) is used to reproduce the color of the target device in the device to be adjusted. CMS is a method for evaluating how much the color of a device to be adjusted reproduces the color of a target device using a color conversion table that converts a color in one color space to a color in another color space. A method of comparing colors when printed on a device can be considered. Patent Document 1 calculates an average value and a maximum value of a color difference between a colorimetric value of a color chart printed by a target device and a colorimetric value of a color chart printed by an adjustment target device, and displays the calculation result. Is disclosed.

JP 2011-10231 A

  There may be a color that cannot be reproduced by the adjustment target device as the color of the target device. A color that cannot be reproduced in the device to be adjusted reproduces a color close to the color. However, the color gamut shape and inclusion relationship between the target device and the device to be adjusted differ depending on the local color gamut, and how much the target device color can be reproduced or how much color difference occurs depends on the local color. . Therefore, it is not possible to locally grasp which color of the target device is reproduced with what color difference only by checking the average value or the maximum value of the color difference.

  An object of the present invention is to provide an information processing apparatus that displays in a recognizable manner which color of a target device is reproduced in a device to be adjusted.

  An information processing apparatus according to an embodiment of the present invention includes a first conversion unit that converts a plurality of predetermined color signals in a first color space into color signals in a second color space using color characteristics of a target device. A second conversion means for converting the predetermined plurality of color signals in the first color space into color signals in the second color space using color characteristics of an adjustment device; and the first color The color signal of the second color space converted by the first conversion unit and the second color space converted by the second conversion unit for each of the predetermined color signals in the space Calculating means for calculating a color difference with respect to the color signal, and display means for displaying the color signal having the calculated color difference larger than a threshold value in a recognizable manner in the second color space.

  According to the information processing apparatus of the present invention, it is possible to display in a recognizable manner which color of the target device is reproduced in the device to be adjusted.

It is a figure which shows the physical structure of the information processing apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the process which visualizes the color difference of a target device and an adjustment object device. It is a figure which shows a screen display process. It is a figure which shows an example of an initial screen. It is a figure which shows an example of a threshold value registration screen. It is a figure which shows an example of the visualization screen of a color difference. It is a figure which shows the process which concerns on the update of a screen. It is a figure explaining the process until it draws the outer frame of a target device. It is a figure which shows the process which extracts the outer frame candidate point of a target device. It is a figure explaining the process until an outer frame of a device for adjustment is drawn. It is a figure which shows the process which extracts the outer frame candidate point of a device for adjustment. It is a figure explaining the process until it draws a boundary line. It is a figure which shows the process which extracts a boundary line candidate point. It is a figure which shows a screen display process. It is a figure which shows the visualization screen of the color difference displayed by the update of a screen.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a diagram showing a physical configuration of an information processing apparatus according to an embodiment of the present invention.
The information processing apparatus includes an internal bus 101, a CPU 102, a RAM 103, an external storage device 104, a display interface 105, an external input device 106, a network interface 107, and a display 108. When the information processing apparatus is activated, the CPU 102 reads an application execution program from the external storage device 104, stores it in the RAM 103, and executes the program to control the information processing apparatus. Note that the information processing apparatus according to the present embodiment only needs to read data relating to a target device and an adjustment target device, which will be described later, and execute processing described below. For example, it can be executed by a processing unit of an image processing apparatus (printer or the like) such as a target device or an adjustment device.

  The program executed by the CPU 102 starts transmitting screen display data to the display interface 105 and outputs the screen to the display 108. Further, the CPU 102 monitors the input of information by the user from the external input device 106, and when information is input, executes processing corresponding to the input information by the user defined in the program. Each process such as determination and conditional branching described below is performed by the CPU 102 in accordance with a program, and data generated during the process is temporarily stored in the RAM 103 and reused in other processes.

FIG. 2 is a flowchart for describing processing for visualizing the color difference between the target device and the adjustment target device executed by the CPU 102.
In the following, a device that wants to inherit color, such as a device before replacement or a handheld device, will be referred to as a target device, and a device that inherits color, such as a device after replacement or a purchased device, will be referred to as an adjustment target device. To do.

  In step S <b> 201, the CPU 102 acquires the color characteristics of the target device stored in advance in the external storage device 104 and stores them in the RAM 103. The color characteristic of the target device is a data group composed of coordinates (L * a * b * values) in the L * a * b * color space (second color space), and is obtained by the following processing. For example, image data in which patches of signal values (coordinates) of color signals obtained by sampling the coordinates of the sRGB color space (first color space) at equal intervals are processed by CMS, printed by the target device, and measured. It can be obtained by colorimetry.

  Hereinafter, the obtained L * a * b * values will be described as lattice points (tgtP (0) to tgtP (N)) constituting the color characteristics of the target device. Here, N is an arbitrary integer greater than or equal to 0, and the color characteristics of the target device are assumed to be composed of N L * a * b * value lattice points. The sRGB color space is an international standard for color spaces established by the IEC (International Electrotechnical Commission), and is a color space defined to ensure color reproducibility between different environments such as input / output devices. It is. The L * a * b * value is a value in the L * a * b * color space established by the CIE (International Lighting Commission). The L * a * b * color space is a device-independent three-dimensional color space in consideration of human visual characteristics (visual equality).

  The aforementioned “signal value obtained by sampling the coordinates of the sRGB color space at equal intervals” has components in three directions of the R axis, the G axis, and the B axis. The case where the coordinates are expressed by 8 bits and the signal value interval is 32 is as follows. (R-axis component, G-axis component, B-axis component) = (0,0,0), (0,0,32),..., (0,0,255), (0,32, (0, 255, 255), (32, 0, 0), ... (255, 0, 0), ... (255, 255, 255).

  Each point of tgtP (0) to tgtP (N) has three components (elements) of the L * axis, a * axis, and b * axis of the L * a * b * color space. Hereinafter, the three components of Lgt axis, a * axis, and b * axis of tgtP (i) will be described as tgtP_L (i), tgtP_a (i), and tgtP_b (i). Here, i is an arbitrary integer from 0 to N. N is an integer of 0 or more.

  In step S <b> 202, the CPU 102 acquires the color characteristics of the adjustment target device stored in advance in the external storage device 104, and stores them in the RAM 103. The color characteristic of the device to be adjusted is a data group composed of L * a * b * values obtained by the following processing. For example, image data in which a plurality of patches with equal RGB value intervals are arranged is printed by an adjustment target device without being processed by CMS, and is measured by a measuring instrument. By “printing without performing processing by CMS”, an L * a * b * value for a signal value in the RGB color space (devRGB color space) depending on the device to be adjusted is obtained.

  Hereinafter, the obtained L * a * b * values will be described as the lattice points (devP (0) to devP (N)) constituting the color characteristics of the device to be adjusted. Here, N is an arbitrary integer greater than or equal to 0, and the color characteristics of the device to be adjusted are composed of N L * a * b * value lattice points. Each point of devP (0) to devP (N) has three components of the L * axis, a * axis, and b * axis of the L * a * b * color space. Hereinafter, the three components of L * axis, a * axis, and b * axis of devP (i) will be described as devP_L (i), devP_a (i), and devP_b (i). Here, i is an arbitrary integer from 0 to N. N is an integer greater than or equal to 0, and is the same number as N in the color characteristics tgtP (0) to tgtP (N) of the target device.

  In step S <b> 203, the CPU 102 creates a CustommLUT using the color characteristics of the target device and the color characteristics of the adjustment target device. The CustommLUT is a color conversion table that converts the sRGB color space into a devRGB color space that depends on the adjustment target device. The CustommLUT is composed of points cstP (0) to cstP (N) in the devRGB color space corresponding to coordinates obtained by sampling the coordinates in the sRGB color space at equal intervals.

  An arbitrary point cstP (i) of the CustommLUT is composed of coordinate values in the devRGB color space. Hereinafter, the coordinate values of the devRGB color space constituting cstP (i) are expressed as (R-axis component, G-axis component, B-axis component) = (cstP_R (i), cstP_G (i), cstP_B (i)) Will be described. Here, i is an arbitrary integer from 0 to N. N is an integer of 0 or more. By using CustommLUT in CMS during printing, it is possible to approximate the color characteristics of the target device.

  cstP (i) is obtained as follows. A signal in devRGB color space that can calculate the coordinate value of L * a * b * space that is the same as or closest to tgtP_L (i), tgtP_a (i), and tgtP_b (i), which are components of the color characteristic tgtP (i) of the target device A value is searched based on the color characteristics of the device to be adjusted. The signal value of the searched devRGB color space is cstP (i). The CPU 102 stores cstP (0) to cstP (N) created in this process in the RAM 103.

  In step S <b> 204, the CPU 102 performs color calculation processing of the device to be adjusted using the CustommLUT. First, the CustommLUT created in step S <b> 203 is acquired from the RAM 103. Then, the CPU 102 inputs the same signal value as the signal value obtained by sampling the sRGB color space described in step S201 at equal intervals, performs interpolation using the ComputeLUT, and calculates the signal value of the devRGB color space.

  Further, the CPU 102 performs an interpolation operation on the calculated signal value of the devRGB color space using the color characteristics of the device to be adjusted, and obtains a signal value of the L * a * b * color space. As a complementary calculation method, for example, tetrahedral interpolation is performed. The calculated signal values are stored in the RAM 103 as devP_cst (0) to devP_cst (N). devP_cst (i) is composed of three components that specify the coordinates of the L * a * b * color space, and the three components are (L-axis component, a-axis component, b-axis component) = (devP_cst_L (i) , DevP_cst_a (i), devP_cst_b (i)).

  In step S205, the CPU 102 calculates a color difference. The CPU 102 calculates the color difference between the color characteristics (tgtP (0) to tgtP (N)) of the target device and the color characteristics (devP_cst (0) to devP_cst (N)) of the device to be adjusted after customization. For example, the following formula (1) is used to calculate the color difference.

  The calculated color differences dE (0) to dE (N) are stored in the RAM 103. In step S206, the CPU 102 performs screen display processing using the calculated color difference information. Details of the screen display process will be described later.

FIG. 3 is a flowchart for explaining a screen display process executed by the CPU 102.
In step S301, the CPU 102 displays an initial screen 401 (FIG. 4) on the display 108.

FIG. 4 is a diagram illustrating an example of the initial screen.
The initial screen 401 includes an L * value setting area 402, an L * value setting bar 403, a color gamut display area 404, a legend area 405, and a threshold value registration button 406. The L * value setting bar 403 can be moved up and down in the L * value setting area 402 by the user using the external input device 106, and the L * value is set to a number between 0 and 100. Can do. When the CPU 102 determines that the L * value setting bar 403 is stationary, the CPU 102 stores the position information where the L * value setting bar 403 is stationary in the external storage device 104 as the current L * value. When the user presses the threshold value registration button 406 using the external input device 106, a threshold value registration screen 501 (FIG. 5) is drawn on the display.

FIG. 5 is a diagram illustrating an example of the threshold value registration screen.
The threshold registration screen 501 has a threshold list display area 502, a color difference input area 503, a numerical value input area 504, a threshold addition button 505, and a completion button 506. The threshold list display area 502 is an area for displaying threshold values stored in the external storage device 104. A numerical value input area 504 in the color difference input area 503 is an area where the user can input an arbitrary numerical value using the external input device 106. That is, the user can specify an arbitrary value as the threshold value.

  When the user presses the threshold addition button 505 with the external input device 106 while a numerical value is input in the numerical value input area 504, the CPU 102 registers the relevant numerical value as a threshold (stores in the external storage device 104). Then, the CPU 102 draws with the registered threshold value added to the threshold value list display area 502. When the user presses the completion button 506 with the external input device 106, the threshold value registration screen 501 is closed.

  Returning to the description of FIG. In step S302, the CPU 102 acquires the color characteristics of the target device, the color characteristics of the adjustment target device, and the color difference. Specifically, the color characteristics of the target device refer to the data acquired from the external storage device 104 in step S201 and temporarily stored in the RAM 103. For the color characteristics of the device to be adjusted, refer to the data acquired from the external storage device 104 in step S202 and temporarily stored in the RAM 103. The color difference is calculated in step S205 and refers to data temporarily stored in the RAM 103.

  In step S303, the CPU 102 acquires an L * value. This L * value is a value set by the L * value setting bar 403 on the initial screen 401 and stored in the external storage device 104. The CPU 102 acquires the L * value and stores it in the RAM 103. In step S304, the CPU 102 acquires a threshold value. The threshold is a value displayed in the threshold list display area 502 of the threshold registration screen 501 and is stored in the external storage device 104. The CPU 102 acquires the threshold value from the external storage device 104 and stores it in the RAM 103. In step S305, the CPU 102 updates the screen. Specifically, a color difference visualization screen 601 (FIG. 6) is displayed on the display 108.

FIG. 6 is a diagram illustrating an example of a color difference visualization screen displayed by updating the screen in step S305.
By updating the screen in step S305, the target device reproduction range 602, the adjustment target device reproduction range 604, and the boundary line 603 are drawn on the color difference visualization screen 601. Details of processing related to these drawing will be described later with reference to FIG.

  In the present embodiment, the drawing is performed in the color gamut display area 404 of the color difference visualization screen 601 using the coordinate system of the horizontal axis a * and the vertical axis b *, but the present invention is not limited to this. You may define and draw axes such as brightness and hue. Further, the reproduction range 604 of the adjustment target device drawn on the color difference visualization screen 601 may not be drawn.

  In step S306, the CPU 102 determines whether or not the L * value or the threshold value has been updated. Specifically, when the L * value acquired in step S303 and stored in the RAM 103 is different from the L * value changed by the L * value setting bar 403 and stored in the external storage device 104, the L * value is stored. Is determined to have been updated. Further, when the threshold value acquired in step S304 and stored in the RAM 103 is different from the threshold value registered in the threshold value registration screen 501 and stored in the external storage device, it is determined that the threshold value has been updated.

  If it is determined that the L * value or the threshold value has been updated, the CPU 102 executes the processing from step S303 to step S305 again to update the color difference visualization screen. When determining that the L * value or the threshold value has not been updated, the CPU 102 repeatedly executes the process of step S306 at regular time intervals.

FIG. 7 is a flowchart for explaining the details of the processing relating to the screen update in step S305.
In step S701, the CPU 102 extracts a grid point having a specific L * value from the color characteristics of the target device. Specifically, the grid points having the L * value acquired in step S303 are extracted from the grid points tgtP (0) to tgtP (N) constituting the color characteristics of the target device. Here, the following description will be made assuming that the extracted lattice points are t. The extracted t lattice points are tgtP_ext (0) to tgtP_ext (t). When i is an arbitrary integer in the range of 0 to t, tgtP_ext (i) is an L * a * b * value, and the three components of the L * axis, a * axis, and b * axis are represented by tgtP_ext_L ( i), tgtP_ext_a (i), tgtP_ext_b (i).

  The CPU 102 stores tgtP_ext (0) to tgtP_ext (t) in the RAM 103. The specific L * value may be the L * value itself acquired in step S303, but an arbitrary width may be given to the L * value. For example, when the L * value acquired in step S303 is 20, the grid point tgtP (0) of the color characteristic of the target device having a width of 5 up and down and the L * value in the range of 15 to 25 is provided. ~ TgtP (N) may be extracted.

FIG. 8 is a diagram showing a two-dimensional plane (chromaticity diagram) based on the coordinate system of the horizontal axis a * and the vertical axis b * drawn in the color gamut display area 404 shown in FIG. It is a figure explaining the process until an outer frame of (color reproduction range) is drawn.
FIG. 8 shows specific L * -value grid points, outer frame candidate points, hue classification lines, outer frame lines used until the outer frame of the color reproduction area of the target device is drawn by the processing in steps S701 to S703. The image is shown. However, only the outer frame is actually drawn in the color gamut display area 404, and the others are shown for explanation.

  An area divided by the hue classification line is referred to as a hue group, and each hue group is denoted as H (0) to H (K-1). In the example of FIG. 8, the hue group is divided into 12 groups H (0) to H (11) with K = 12, but the present invention is not limited to this, and K = 12 is not necessary. Points tgtP_ext (0) to tgtP_ext (t) extracted by the processing in step S701 include the following points shown in FIG. That is, it includes lattice points (tgtP_ext (0) to tgtP_ext (t)) and outer frame candidate points (tgt_edgP (0) to tgt_edgP (K-1)) having specific L * values.

  In step S <b> 702, the CPU 102 extracts points that are candidates for the outer frame (outer frame candidate points) from the lattice points that form the color characteristics of the target device. The extracted outer frame candidate points are stored in the RAM 103 as tgt_edgP (0) to tgt_edgP (K−1). K is an arbitrary integer and represents the number of hue divisions. When the value of K is increased, the outer frame line becomes smoother. Conversely, when the value of K is decreased, the outer frame line becomes rougher. The process of step S702 will be described later with reference to FIG. FIG. 8 shows a case where the number of hue divisions is 12 (K = 12), and there are 12 outer frame candidate points from tgt_edgP (0) to tgt_edgP (11).

  In step S <b> 703, the CPU 102 acquires the outer frame candidate points (tgt_edgP (0) to tgt_edgP (K−1)) of the target device from the RAM 103, and connects the outer frame candidate points to each other on the color difference visualization screen 601. Draw. Specifically, the coordinates of tgt_edgP (i) and tgt_edgP (i + 1) on the a * b * plane (two-dimensional plane in the coordinate system of the horizontal axis a * and the vertical axis b * displayed in the color gamut display area 404). Draw a line segment connecting the coordinates of).

  The coordinates of tgt_edgP (i) on the a * b * plane are (tgt_edgP_a (i), tgt_edgP_b (i)). Similarly, the coordinates on the a * b * plane of tgt_edgP (i + 1) are (tgt_edgP_a (i + 1), tgt_edgP_b (i + 1)). Thereby, a line connecting the outer frame candidate points located in the adjacent hues can be drawn. In FIG. 8, the line drawn by the process of step S <b> 703 is a line indicated as “outer frame”.

  In step S704, the CPU 102 extracts a grid point having a specific L * value from the color characteristics of the adjustment target device. Specifically, the points having the L * value acquired in step S303 are extracted from the grid points devP (0) to devP (N) that constitute the color characteristics of the device to be adjusted. Here, the following description will be made assuming that the number of extracted lattice points is u. The extracted u lattice points are devP_ext (0) to devP_ext (u). When i is an arbitrary integer in the range of 0 to u, devP_ext (i) is an L * a * b * value, and the three components of the L * axis, a * axis, and b * axis are set to devP_ext_L ( i), devP_ext_a (i), devP_ext_b (i).

  The CPU 102 stores devP_ext (0) to debP_ext (u) in the RAM 103. The specific L * value may be the L * value itself acquired in step S303, but an arbitrary width may be given to the L * value. For example, when the L * value acquired in step S303 is 20, the grid point devP (0) of the color characteristic of the target device having a width of 5 up and down and the L * value in the range of 15 to 25 ~ DevP (N) may be extracted.

FIG. 10 is a diagram showing a two-dimensional plane (chromaticity diagram) based on the coordinate system of the horizontal axis a * and the vertical axis b * drawn in the color gamut display area 404 shown in FIG. It is a figure explaining the process until it draws the outer frame of a field (color reproduction range).
FIG. 10 shows specific L * -value grid points, outer frame candidate points, hue classification lines, outer frame, and the like used until the outer frame of the color reproduction area of the device to be adjusted is drawn by the processing in steps S704 to S706. The image is shown. However, only the outer frame is actually drawn in the color gamut display area 404, and the others are shown for explanation.

  An area divided by the hue classification line is referred to as a hue group, and each hue group is denoted as H (0) to H (K-1). In the example of FIG. 10, the hue group is divided into 12 groups H (0) to H (11) with K = 12, but the present invention is not limited to this, and K = 12 is not necessary. The points devP_ext (0) to devP_ext (u) extracted in step S704 include the following points shown in FIG. That is, it includes lattice points (devP_ext (0) to devP_ext (u)) and outer frame candidate points (dev_edgP (0) to dev_edgP (K-1)) having specific L * values.

  In step S <b> 705, the CPU 102 extracts points (outer frame candidate points) that are candidates for the outer frame from the lattice points that form the color characteristics of the device to be adjusted. The extracted outer frame candidate points are stored in the RAM 103 as dev_edgP (0) to dev_edgP (K−1). K is an arbitrary integer and represents the number of hue divisions. When the value of K is increased, the outer frame line becomes smoother. Conversely, when the value of K is decreased, the outer frame line becomes rougher. The process of step S705 will be described later with reference to FIG. FIG. 10 shows a case where the number of hue divisions is 12 (K = 12), and there are 12 outer frame candidate points, dev_edgP (0) to dev_edgP (11).

  In step S706, the CPU 102 acquires the outer frame candidate points (dev_edgP (0) to dev_edgP (K-1)) of the adjustment target device from the RAM 103, and connects the outer frame candidate points to each other on the color difference visualization screen 601. Draw minutes. Specifically, the coordinates of dev_edgP (i) and dev_edgP (i + 1) on the a * b * plane (two-dimensional plane in the coordinate system of the horizontal axis a * and the vertical axis b * displayed in the color gamut display area 404). Draw a line segment connecting the coordinates of).

  The coordinates of dev_edgP (i) on the a * b * plane are (dev_edgP_a (i), dev_edgP_b (i)). Similarly, the coordinates on the a * b * plane of dev_edgP (i + 1) are (dev_edgP_a (i + 1), dev_edgP_b (i + 1)). Thereby, a line connecting the outer frame candidate points located in the adjacent hues can be drawn. In FIG. 10, the line drawn by the process of step S <b> 706 is a line indicated as “outer frame”.

  In step S <b> 707, the CPU 102 extracts points (boundary line candidate points) that are candidates for the boundary line. Specifically, boundary line candidate points are extracted from the points tgt_extP (0) to tgt_extP (t) extracted in step S701 and stored in the RAM 103 as bdrP (0) to bdrP (K-1).

FIG. 12 is a diagram showing a two-dimensional plane (chromaticity diagram) based on the coordinate system of the horizontal axis a * and the vertical axis b * drawn in the color gamut display area 404 shown in FIG. 4 until the boundary line is drawn. It is a figure explaining the process of.
In FIG. 12, the grid line candidate point of the specific L * value used until the boundary line is drawn by the processing of step S707 and step S708, the boundary line candidate point among the points whose color difference is larger than a predetermined value (threshold value) Th1, and Points other than boundary line candidate points, hue classification lines, and boundary line images are shown. However, only the boundary line is actually drawn in the color gamut display area 404. Others are shown for illustrative purposes.

  An area divided by the hue classification line is referred to as a hue group, and each hue group is denoted as H (0) to H (K-1). In the example of FIG. 12, K = 12. In FIG. 12, points bdrP (0) to bdrP (K-1) extracted by the process of step S707 are points indicated as boundary line candidate points. Details of the processing in step S707 will be described later with reference to FIG.

  In step S708, the CPU 102 draws a boundary line. Specifically, boundary line candidate points bdrP (0) to bdrP (K-1) are acquired from the RAM 103, and a line segment connecting the boundary line candidate points is drawn on the color difference visualization screen 601. Specifically, the coordinates of bdrP (i) on the a * b * plane (bdrP_a (i), bdrP_b (i)) and the coordinates of bdrP (i + 1) (bdrP_a (i + 1), bdrP_b (i + 1)) Draw a line segment connecting. As a result, a line connecting the boundary line candidate points located in the adjacent hues can be drawn. In FIG. 12, the line drawn by the process of step S <b> 708 is a line indicated as a “boundary line” between the color reproduction area of the target device and the color reproduction area of the adjustment target device.

  In the present embodiment, the boundary line is covered with the threshold value Th1, but when a plurality of threshold values are registered on the threshold value registration screen 501 shown in FIG. 5, a plurality of boundary lines are displayed in the color gamut display area 404. May be. With the above processing, the processing related to the screen update in step S305 is completed.

FIG. 9 is a flowchart for explaining the details of the process of extracting outer frame candidate points from the color characteristics of the target device in step S702.
In step S901, the CPU 102 acquires an initial value of the saturation of each hue. The CPU 102 stores the initial value of saturation stored in the external storage device 104 in the RAM 103. The initial value of saturation is the initial value of saturation in each of the hues divided between K and 0 to 2π. For example, 0 is stored. In the subsequent processing, the initial value of saturation is set to tgt_Cdef (0) to tgt_Cdef (K-1).

  In step S902, the CPU 102 sets an arbitrary integer i to 0. In step S903, the CPU 102 calculates the saturation of the point tgt_extP (i) among the points extracted in step S701. When the saturation to be calculated is tgtP_ext_C (i), the saturation is obtained by the following equation (2).

  In step S904, the CPU 102 obtains the hue of the point tgt_extP (i) from the points extracted in step S701 by using equation (3). And CPU102 calculates | requires the group number Hgr showing which of the calculated | required hue belongs to hue group H (0) -H (K-1) by following formula (4). The CPU 102 stores the obtained group number Hgr in the RAM 103.

  In step S905, the CPU 102 compares the magnitude relationship between the saturation tgtP_ext_C (i) obtained in step S903 and the initial saturation value tgt_Cdef (Hgr) of the hue group Hgr obtained in step S904. When tgtP_ext_C (i)> tgt_Cdef (Hgr), the CPU 102 executes the process of step S906. When tgtP_ext_C (i) <= tgt_Cdef (Hgr), the CPU 102 executes the process of step S908.

  In step S <b> 906, the CPU 102 changes the saturation value tgt_Cdef (Hgr) of the hue group Hgr to the saturation value of tgtP_ext_C (i), and stores it in the RAM 103. In step S907, the CPU 102 changes the value of the outer frame candidate point tgt_edgP (Hgr) of the hue group Hgr to tgtP_ext (i) and stores it in the RAM 103.

  In step S908, the CPU 102 increases the value of an arbitrary integer i by one. In step S909, the CPU 102 determines whether or not the current i exceeds t. t is the number of points (tgtP_ext (0) to tgtP_ext (t)) extracted in step S701. If the CPU 102 determines that the current i exceeds t, the process ends. On the other hand, if the CPU 102 determines that the current i does not exceed t, the CPU 102 starts processing in step S903. With the above processing, the extraction of the outer frame candidate points of the color characteristics of the target device in step S702 is completed.

FIG. 11 is a flowchart for explaining the details of the process of extracting outer frame candidate points from the color characteristics of the adjustment target device in step S705.
In step S1101, the CPU 102 acquires an initial value of the saturation of each hue. The CPU 102 stores the initial value of saturation stored in the external storage device 104 in the RAM 103. The initial value of saturation is the initial value of saturation in each of the hues divided between K and 0 to 2π. For example, 0 is stored. In the subsequent processing, the initial value of saturation is set to dev_Cdef (0) to dev_Cdef (K-1).

  In step S1102, the CPU 102 sets an arbitrary integer i to 0. In step S1103, the CPU 102 calculates the saturation of the point dev_extP (i) among the points extracted in step S704. When the saturation to be calculated is devP_ext_C (i), the saturation is obtained by the following equation (5).

  In step S1104, the CPU 102 obtains the hue of the point dev_extP (i) from the points extracted in step S701 by using equation (6). Then, the CPU 102 obtains a group number Hgr indicating which of the obtained hues belongs to one of the hue groups H (0) to H (K-1) by the following formula (7). The CPU 102 stores the obtained group number Hgr in the RAM 103.

  In step S1105, the CPU 102 compares the magnitude relationship between the saturation devP_ext_C (i) obtained in step S1103 and the initial saturation value dev_Cdef (Hgr) of the hue group Hgr obtained in step S1104. When devP_ext_C (i)> dev_Cdef (Hgr), the CPU 102 executes the process of step S1106. When devP_ext_C (i) <= dev_Cdef (Hgr), the CPU 102 executes the process of step S1108.

  In step S <b> 1106, the CPU 102 changes the saturation value dev_Cdef (Hgr) of the hue group Hgr to the saturation value of devP_ext_C (i) and stores it in the RAM 103. In step S <b> 1107, the CPU 102 changes the value of the outer frame candidate point dev_edgP (Hgr) of the hue group Hgr to devP_ext (i) and stores it in the RAM 103. In step S1108, the CPU 102 increases the value of an arbitrary integer i by one.

  In step S1109, the CPU 102 determines whether or not the current i exceeds u. u is the number of points (devP_ext (0) to devP_ext (u)) extracted in step S704. If the CPU 102 determines that the current i exceeds u, the process ends. On the other hand, if the CPU 102 determines that the current i does not exceed u, the CPU 102 starts the process of step S1103. With the above processing, the extraction of the outer frame candidate points of the color characteristics of the device to be adjusted in step S705 is completed.

FIG. 13 is a flowchart illustrating details of the process of extracting boundary line candidate points in step S707.
In step S <b> 1301, the CPU 102 acquires the color differences dE (0) to dE (N) from the RAM 103. In step S <b> 1302, the CPU 102 acquires the threshold value Th <b> 1 from the external storage device 104 and stores it in the RAM 103. As the threshold Th1, for example, 3 is stored in advance.

  In step S1303, the CPU 102 acquires an initial value of the saturation of each hue. The CPU 102 acquires the initial saturation values bdr_Cdef (0) to bdr_Cdef (N) of the external storage device 104 and stores them in the RAM 103. For bdr_Cdef (i), for example, a large value such as 10,000 is stored in advance. In step S1304, the CPU 102 sets an arbitrary number i to 0.

  In step S1305, the CPU 102 compares the magnitude relationship between the color difference dE (i) acquired in step S1301 and the threshold Th1 acquired in step S1302. If dE (i)> Th1, the CPU 102 executes the process of step S1306. On the other hand, when dE (i) <= Th1, the CPU 102 executes Step S1311. In step S1306, the CPU 102 calculates the saturation of tgt_extP (i). Since this process is the same as the process of step S903, description thereof is omitted. The calculated saturation is stored in the RAM 103 as tgtP_ext_C (i).

  In step S1307, the CPU 102 calculates the hue of tgt_extP (i). Since this process is the same as the process of step S904, description thereof is omitted. The CPU 102 stores the hue group number Hgr representing the hue group to which the calculated hue belongs in the RAM 103. In step S1308, the CPU 102 compares the magnitude relationship between the saturation tgtP_ext_C (i) of tgt_extP (i) and the initial saturation value bdr_Cdef (Hgr). If tgtP_ext_C (i) <bdr_Cdef (Hgr), the CPU 102 executes the process of step S1309. When tgtP_ext_C (i)> = bdr_Cdef (Hgr), the CPU 102 executes the process of step S1311.

  In step S <b> 1309, the CPU 102 rewrites the value of the saturation initial value bdr_Cdef (Hgr) with the value of the saturation tgtP_ext_C (i) of tgt_extP (i), and stores it in the RAM 103. That is, in each hue, a point with the minimum saturation is extracted as a boundary line candidate point from tgt_extP (i) where the color difference from the adjustment target device is larger than the threshold value. In step S1310, the CPU 102 sets the point tgt_extP (i) as the boundary line candidate point bdrP (Hgr). In step S1311, the CPU 102 increases the value of i by one.

  In step S1312, the CPU 102 determines whether or not the current i and t are exceeded. If i> t, the process ends. If i <= t, the process of step S1305 is executed. With the above processing, extraction of boundary candidate points in step S707 is completed.

  As described above, according to the present embodiment, the user can easily recognize which color of the target device is reproduced in the adjustment device with what color difference.

(Second Embodiment)

  In the first embodiment, the boundary line 603 is drawn on the color difference visualization screen 601 to identify how much the specific color of the target device is reproduced. In the present embodiment, a color in an arbitrary L * a * b * space is selected on the color difference visualization screen 601 and a detailed color difference is displayed as to how much the selected color is reproduced. Make it possible. Note that the physical configuration of the information processing apparatus according to the present embodiment and the process of visualizing the color difference between the target device and the adjustment target device are the same as those in the first embodiment, and thus description thereof is omitted. The processing in the second embodiment is performed by the CPU 102 reading and executing a program loaded in the RAM 103.

FIG. 14 is a flowchart illustrating screen display processing executed by the CPU 102 in the present embodiment.
Steps S1401 to S1402 are the same as steps S301 to S302 of the screen display process (FIG. 3) in the first embodiment, and thus description thereof is omitted. Further, steps S1404 to S1407 are the same processes as steps S303 to S306, and thus description thereof is omitted.

  In step S1403, the CPU 102 calculates a reverse characteristic of the target device. The inverse characteristic of the target device is a color conversion table (rev_tgtP (0) to rev_tgtP (M)) that represents the correspondence of the coordinates of the sRGB color space to the coordinates of an arbitrary L * a * b * color space. M is an integer of 0 or more. The color conversion table (rev_tgtP (0) to rev_tgtP (M)) includes M sRGB value grid points, and each grid point rev_tgtP (i) has three components (elements) that can specify the coordinates of the sRGB color space. Have

  Hereinafter, the three components of the R-axis, G-axis, and B-axis of rev_tgtP (i) will be described as rev_tgtP_R (m), rev_tgtP_G (m), and rev_tgtP_B (m). Here, i is an arbitrary integer from 0 to M. The CPU 102 stores the calculated inverse characteristics (rev_tgtP (0) to rev_tgtP (M)) of the target device in the RAM 103. In step S1408, the CPU 102 determines whether coordinates have been selected. Here, FIG. 15 will be described.

FIG. 15 is a diagram showing a color difference visualization screen displayed by updating the screen in step S1406.
The user selects coordinates by moving an arrow 1501 using an external input device 106 at an arbitrary position in the color gamut display area 404 of the color difference visualization screen. The color difference display area 1502 displays the color difference calculated based on the coordinates (selected) indicated by the arrow 1501.

  In the processing of step S1408, whether or not the coordinate is selected depending on whether or not there is an arrow 1501 on the two-dimensional plane in the coordinate system of the horizontal axis a * and the vertical axis b * drawn on the color gamut display area 404. Judging. In the present embodiment, coordinate selection by an arrow has been described. However, the present invention is not limited to this. For example, coordinates may be directly input, and the selection method is not limited. If it is determined that the coordinates have been selected, the CPU 102 executes the process of step S1409. If it is determined that no coordinate has been selected, the CPU 102 executes the process of step S1407.

  In step S1409, the CPU 102 acquires the selected coordinates. Specifically, the coordinates are coordinates in the L * a * b * color space, and the components of the a * axis and the b * axis are acquired from the position of the arrow 1501 on the color gamut display area 404. Also, the L * axis component is acquired from the value indicated by the L * value setting bar 403. The acquired coordinates (L * -axis component, a * -axis component, b * -axis component) = (tmpP_L, tmpP_a, tmpP_b). The CPU 102 stores tmpP_L, tmpP_a, and tmpP_b in the RAM 103.

  In step S1410, the CPU 102 calculates RGB values. The CPU 102 interpolates tmpP_L, tmpP_a, and tmpP_b stored in the RAM 103 using inverse characteristics (rev_tgtP (0) to rev_tgtP (M)) of the target device, and calculates signal values in the sRGB color space. The CPU 102 stores the calculated signal values of the sRGB color space (R-axis component, G-axis component, B-axis component) = (tmpP_R, tmpP_G, tmpP_G) in the RAM 103.

  In step S1411, the CPU 102 calculates points (signal values) in the corresponding devRGB color space of the device to be adjusted using the CustommLUT. Specifically, interpolation calculation is performed on the tmpP_R, tmpP_G, and tmpP_G stored in the RAM 103 using a CustommLUT to calculate signal values in the devRGB color space. The calculated devRGB color space signal value is (R-axis component, G-axis component, B-axis component) = (tmpP_devR, tmpP_devG, tmpP_devB).

  The calculated tmpP_devR, tmpP_devG, and tmpP_devB are interpolated using the color characteristics of the device to be adjusted, and the signal value of the L * a * b * color space is calculated. The calculated signal value of the L * a * b * color space is (L * axis component, a * axis component, b * axis component) = (tmp_cst_L, tmp_cst_a, tmp_cst_b), and is stored in the RAM 103.

  In step S1412, the CPU 102 calculates a color difference. The color difference between the signal values tmpP_L, tmpP_a, tmpP_b in the L * a * b * color space based on the coordinates acquired in step S1409 and the signal values tmp_cst_L, tmp_cst_a, tmp_cst_b calculated in step S1411 is calculated by the following equation (8). The CPU 102 stores the calculated color difference as tmp_dE in the RAM 103.

  In step S1413, the CPU 102 displays the color difference. The CPU 102 acquires the RGB color space coordinates tmpP_R, tmpP_G, tmpP_G acquired in step S1410 and the color difference tmp_dE calculated in step S1412 from the RAM 103, and displays them on the color difference display area 1502.

  As described above, according to the present embodiment, the user can not only confirm how much of the color of the target device is reproduced in the adjustment target device in the entire color space, but also how much in any color. It is possible to confirm in detail whether there is a color difference.

(Other embodiments)
The present invention supplies a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus read and execute the program This process can be realized. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

102 CPU
103 RAM
104 External storage device 108 Display

Claims (9)

First conversion means for converting a plurality of predetermined color signals in the first color space into color signals in the second color space using the color characteristics of the target device;
Second conversion means for converting the predetermined plurality of color signals in the first color space into color signals in the second color space using color characteristics of an adjustment device;
For each of the predetermined color signals in the first color space, the color signal in the second color space converted by the first conversion means and the color signal converted by the second conversion means. Calculating means for calculating a color difference from the color signal of the second color space;
An information processing apparatus comprising: display means for displaying a color signal having the calculated color difference larger than a threshold value in a recognizable manner in the second color space. The information processing apparatus according to claim 1, wherein the display unit displays a color signal having the calculated color difference larger than the threshold on a chromaticity diagram for each designated brightness. In the chromaticity diagram, the display means obtains a color signal that minimizes the color difference for each hue from among the color signals having the calculated color difference larger than the threshold, and displays a line connecting the obtained color signals. The information processing apparatus according to claim 2, wherein the information processing apparatus is displayed as a boundary line of each color reproduction region of the target device and the adjustment device. The information processing apparatus according to claim 3, further comprising a specifying unit that specifies a threshold value used by the display unit. When a plurality of threshold values are designated by the designation means, the display means displays a plurality of the boundary lines.
The information processing apparatus according to claim 4. The display means includes
Based on the color signal of the second color space converted by the first conversion means, the color reproduction region of the target device is displayed recognizable in the chromaticity diagram,
6. The color reproduction area of the adjustment device is recognizablely displayed on the chromaticity diagram based on the color signal of the second color space converted by the second conversion means. The information processing apparatus according to any one of the above. The display means includes
Selecting means for selecting a color in the chromaticity diagram;
The information processing apparatus according to any one of claims 2 to 6, wherein when a color is selected by the selection unit, a color difference corresponding to the selected color is displayed. A first conversion step of converting a plurality of predetermined color signals in the first color space into color signals in the second color space using the color characteristics of the target device;
A second conversion step of converting the predetermined plurality of color signals of the first color space into color signals of the second color space using color characteristics of an adjustment device;
For each of the predetermined color signals in the first color space, the color signal in the second color space converted in the first conversion step and the color signal converted in the second conversion step. A calculation step of calculating a color difference from the color signal of the second color space;
A display step of displaying a color signal having a calculated color difference larger than a threshold value in a recognizable manner in the second color space.   The program for functioning a computer as each means with which the information processing apparatus of any one of Claim 1 thru | or 7 is provided.

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