JP5673933B2 - CONVERSION INFORMATION CREATION DEVICE AND CONVERSION INFORMATION CREATION PROGRAM - Google Patents

Description

  The present invention relates to a conversion information creation device and a conversion information creation program.

  With the digitization of the printing industry, an output result from a target output device is reproduced in a pseudo manner on another output device. For this purpose, a plurality of color values are given to the target output device (target output device), the output color is measured to obtain a color measurement value, and the given color value and the color measurement value are obtained. Corresponding to the target output value pair. On the other hand, in another output device (actual output device), a plurality of color values are given, the output color is measured to obtain a colorimetric value, and the color value and the colorimetric value are associated with each other and actually output. Value pairs. Then, from the target output value pair and the actual output value pair, creation of conversion information for converting the color when the given color value is output by the target output device into a color value for reproduction by the actual output device is created. To do.

  As a method of creating conversion information from such a target output value pair and an actual output value pair, for example, there is a method described in Patent Document 1 or the like. In the method described in Patent Document 1, when obtaining the color difference in each color value, the color difference in each color value is obtained by weighting according to the distance, and conversion information is created so that the overall color difference is minimized. ing. Since the color difference of another color value acts on the color difference at a certain color value, even if an unexpected pair is included, the influence is reduced and continuity is ensured.

  On the other hand, when reproducing the color of a natural image, the reproduction of a specific color such as skin, gray, or sky may be emphasized. For such important colors (important colors), even if color conversion is performed so that the color difference between the color reproduced by the target output device and the color reproduced by the actual output device is minimized, the color shifts. The appearance of the reproduced color changes depending on the direction.

  For example, the operator may manually adjust the color and create final conversion information. Also, for example, in Patent Document 2, the important color is color-converted using the created conversion information and output from the actual output device, and the color difference from the important color output by the target output device is determined from the target output value pair. The conversion information is corrected by adding the color difference to the colorimetric value for the pair used for color conversion.

Japanese Patent No. 3767657 JP 2000-203094 A

  An object of the present invention is to provide a conversion information creation apparatus and a conversion information creation program capable of creating conversion information in which color adjustment of important colors is performed while maintaining consistency of color conversion in the entire color gamut. Is.

  According to the first aspect of the present invention, a target output value pair which is a pair associated with a color value obtained by giving a colorimetric value obtained by measuring a color output by giving a plurality of color values to the target output device. The target color value from the actual output value pair that is a pair that corresponds to the color value that gives the colorimetric value obtained by measuring the color that is output by giving multiple color values to the actual output device Creation means for creating conversion information for converting the color when output by the output device into a color value for reproduction by the actual output device, and a plurality of evaluations that are color values for evaluation given in advance Selection means for selecting, as a management color value, the evaluation color value in a predetermined color range including a pre-set important color among color values, and obtained by converting the management color value according to the conversion information. Adjustment function setting means for setting an adjustment function from a color difference between the converted color value and the management color value; Adjusting means for adjusting the colorimetric value of the target output value pair by the adjustment function set by the adjustment function setting means, and the creating means converts the conversion from the adjusted target output value pair and the actual output value pair. A conversion information creating apparatus characterized by creating information.

  The invention described in claim 2 of the present application is the configuration of the invention described in claim 1 of the present application, wherein the management color value selected by the selecting means is converted by the conversion information created by the creating means. A first determination unit that determines whether a color difference between the converted color value and the management color value satisfies a preset condition; the first determination unit determines that the condition is satisfied; In this case, the conversion information creating apparatus is characterized in that the conversion information created by the creating means is output.

  In the invention according to claim 3 of the present application, the evaluation color value is further converted into the configuration of the invention according to claim 1 or claim 2 using the conversion information created by the creating means. There is a second determination means for determining whether the color difference between the color and the color of the original evaluation color value is within a preset range, and adjustment is performed when it is determined that the color difference is within the range. This is a conversion information creation device characterized by this.

  The invention according to claim 4 of the present application is a conversion information creation program that causes a computer to execute the function of the conversion information creation device according to any one of claims 1 to 3. is there.

  According to the first aspect of the present invention, it is possible to obtain conversion information that enables accurate color adjustment of important colors while maintaining consistency of color conversion in the entire color gamut compared to the case without this configuration. .

  According to the second aspect of the present invention, it is possible to obtain conversion information in which important colors are adjusted within a preset range of conditions.

  According to the invention described in claim 3 of the present application, it is possible to prevent unnecessary adjustment.

  According to the invention described in claim 4 of the present application, the effect of the invention described in any one of claims 1 to 3 can be obtained.

It is a block diagram which shows one Embodiment of this invention. It is explanatory drawing of an example of the process which produces conversion information. It is explanatory drawing of an example of the setting method of an important color. It is a conceptual diagram of selection of a management color value. It is explanatory drawing of an example of the selected management color value. It is a flowchart which shows the specific example of the determination process in an adjustment determination part. It is explanatory drawing of an example of an adjustment function. It is explanatory drawing of the specific example of adjustment by an adjustment function. It is a block diagram which shows the example of application of one Embodiment of this invention. FIG. 11 is an explanatory diagram of an example of a computer program, a storage medium storing the computer program, and a computer when the functions described in the embodiment of the present invention and the application example thereof are realized by the computer program.

  FIG. 1 is a configuration diagram showing an embodiment of the present invention. In the figure, 1 is a creation unit, 2 is an accuracy determination unit, 3 is a selection unit, 4 is an adjustment determination unit, 5 is an adjustment function setting unit, and 6 is an adjustment unit. Here, even if a color output when a certain color value is given to a certain target output device (target output device), the color value is given to another output device (actual output device). Conversion information for color conversion is created so as to be output. The conversion information may be called a profile, for example.

  The creation unit 1 converts a given color value from a given target output value pair and an actual output value pair into a color value for reproduction by the actual output device when the given color value is output by the target output device. Create conversion information for Also in the case where the target output value pair and the actual output value pair are adjusted and given by the adjusting unit 6, conversion information is created from the adjusted target output value pair and actual output value pair. The target output value pair is a pair in which a plurality of color values are given to the target output device, the color output from the target output device is measured, and the given color value and the colorimetric value are associated with each other. The actual output value pair is a pair in which a plurality of color values are given to the actual output device, the color output from the actual output device is measured, and the given color value and the measured color value are associated with each other. The color value given to the target output device and the color value given to the actual output device need not be a common color. A known method may be used as a method for creating the conversion information. For example, a method using weighting described in Patent Document 1 may be used.

  The accuracy determination unit 2 uses the conversion information created by the creation unit 1 to convert a set of accuracy evaluation color values that are color values for evaluating accuracy prepared in advance, It is determined whether or not the color difference from the original accuracy evaluation color value is within a preset range. When the color difference is within the range, the processing after the selection unit 3 is performed. When the value is out of the range, it indicates that there is a problem in the conversion accuracy of the conversion information created by the creation unit 1, or that there is a problem in the given target output value pair or actual output value pair. Therefore, the correction process is not performed, and the process ends abnormally, for example. In that case, it is preferable to notify the request source of this processing that there is a problem in the conversion accuracy of the given target output value pair or actual output value pair or the created conversion information. The accuracy evaluation color value may be prepared separately, or may be substituted with the color value of the target output value pair or the color value of the actual output value pair. The accuracy determination unit 2 may not be provided and the process may be performed without performing the determination. Or about the conversion information produced from the target output value pair and the actual output value pair which were adjusted by the adjustment part 6, the determination by this precision determination part 2 does not need to be performed.

  The selection unit 3 selects a color value in a predetermined color range including a preset important color as a management color value. The color range may be a predetermined range for any important color, or a color range corresponding to the important color may be determined. Further, the selection target to be the management color value may be selected from a set of accuracy evaluation color values that are color values for evaluating accuracy prepared in advance. Of course, the color value of the target output value pair or the color value of the actual output value pair may be used as the accuracy evaluation color value. The management color value is selected at the first time, and the management color value selected at the first time is used even when the second and subsequent processes are performed by repetition. Accordingly, in the second and subsequent processes, the selection unit 3 is not processed.

  The adjustment determination unit 4 converts the management color value selected by the selection unit 3 with the conversion information created by the creation unit 1, obtains the color difference between the converted color and the color of the original management color value, and It is determined whether the color difference satisfies a preset condition. If it is determined that the condition is satisfied, the conversion information created by the creation unit 1 is output as the adjustment is completed, and if the condition is not satisfied, the process after the adjustment function setting unit 5 is performed. If the adjustment process is performed once, conversion information created from the target output value pair and the actual output value pair after adjustment by the adjusting unit 6 described later is output without providing the adjustment determining unit 4. The processing may be completed.

  The adjustment function setting unit 5 converts the management color value according to the conversion information created by the creation unit 1 to obtain a conversion color value, and sets the adjustment function from the color difference between the converted color value and the management color value. As described above, even when color conversion is performed using the conversion information obtained with the minimum color difference, the appearance of the reproduced color changes depending on which direction the color is shifted. Accordingly, a function for adjusting the direction of the color difference may be set as the adjustment function. The direction to be adjusted may be determined in advance together with the important color, and is a direction that satisfies the conditions used for determination by the adjustment determination unit 4. In addition, it is preferable to set a function in which the adjustment amount decreases with distance from the important color. The adjustment function is obtained by statistically processing the color difference between the management color value and the converted color value, and may be set using various methods such as an operator setting with reference to the color difference variation.

  The adjustment unit 6 converts the colorimetric values of the target output value pair by the adjustment function set by the adjustment function setting unit 5 and performs color adjustment. The adjusted target output value pair and actual output value pair are given to the creating unit 1 to create adjusted conversion information.

  The configuration of the above-described embodiment will be further described using a specific example. Here, it is assumed that the color values given to the target output device and the actual output device are color values having four elements of C (cyan), M (magenta), Y (yellow), and K (black) as elements. As a value in the LAB color space. Of course, it goes without saying that each value is not limited to these values.

FIG. 2 is an explanatory diagram of an example of processing for creating conversion information. In the figure, 11 is a target output device, and 12 is an actual output device. Assuming that a certain color value (CMYK value) is x and the color value x (LAB value) of the color output by giving the color value x to the target output device 11 is y, the output characteristic F of the target output device 11 is y = Fx (1)
It is represented by When the color measurement value (LAB value) of the color output by giving the color value x to the actual output device 12 is y ′, the output characteristic P of the actual output device 12 is y ′ = Px (2)
It is represented by Due to the difference in output characteristics, even if the color value x is given to the target output device 11 and the actual output device 12, the output color may be different.

If the reverse characteristic of the output characteristic P of the actual output device 12 is P ⁻¹ , y = F (P ⁻¹ P) x from the equation (1)
y = (FP ⁻¹ ) Px (3)
In other words, if the conversion of FP ⁻¹ is performed, the color (y) output from the target output device 11 as the output of the actual output device 12 with respect to the color value x is reproduced. That is, the color value x is converted according to the output characteristic F of the target output device 11 by the equation (1) to obtain the colorimetric value y. Further, the obtained colorimetric value y is converted using the inverse characteristic P ⁻¹ of the output characteristic of the actual output device 12 to obtain the color value x ′. That is,
x ′ = (FP ⁻¹ ) x (4)
Is obtained. When the color value x ′ is given to the actual output device 12, it is converted by the output characteristic P of the actual output device 12.
y ″ = Px ′ (5)
Thus, an output having the colorimetric value y ″ is obtained from the actual output device 12. Theoretically, y = y ″ from the equation (3). This flow is shown in FIG. Here, the information for performing the conversion of FP ⁻¹ is the conversion information created by the creation unit 1.

In order to create this conversion information, the output characteristic F of the target output device 11 and the output characteristic P of the actual output device 12 are required. The output characteristic F of the target output device 11 is obtained from the target output value pair. Since the output characteristic P of the actual output device 12 is also obtained from the actual output value pair, the inverse characteristic P ⁻¹ is also obtained from the inverse correspondence of the actual output value pair.

Theoretically, conversion information can be obtained in this way, but in reality, the target output device and the actual output device have different color gamuts, there are errors in colorimetry, or erroneous data It may be mixed. For this reason, for example, the output characteristic and the reverse characteristic may be acquired using a technique such as Patent Document 1. Note that the inverse characteristic P ⁻¹ of the output characteristic of the actual output device is not uniquely determined because it is converted from three dimensions to four dimensions in this example, but a known technique may be used for the determination method. Due to these various factors, the color conversion based on the generated conversion information may not actually satisfy y = y ″.

After the conversion information is created by the creation unit 1, the accuracy judgment unit 2 determines the conversion accuracy of the conversion information. As described with reference to FIG. 2, when the color value x is converted by the conversion information (FP ⁻¹ ), the color value x ′ to be given to the actual output device is obtained by the equation (4). When this color value x ′ is converted by the output characteristic P of the actual output device, a colorimetric value y ″ is obtained from the equation (5). Theoretically, y = y ″ should be obtained from the equation (3). In practice, y and y ″ may differ due to differences in the color gamut between the target output device and the actual output device, errors in colorimetry, erroneous data, etc. The difference between y and y ″ is the color difference ΔE. And conversion accuracy. As an example, if y = (L ^* ₁ , a ^* ₁ , b ^* ₁ ) and y ″ = (L ^* ₂ , a ^* ₂ , b ^* ₂ ), the color difference ΔE is ΔE = √ ((L ^* ₁₋ L _{^{* 2) 2 + (a *}} 1 -a * 2) 2 + (b * 1 -b * 2) 2) ... (6)
Find it in

  The accuracy determination unit 2 converts, for example, a set of accuracy evaluation color values, which are color values for evaluating accuracy prepared in advance, with conversion information, and further outputs the output characteristics of the actual output device created from the actual output value pairs. Is used to obtain the predicted value (y ″) of the color that will be output from the actual output device. Also, the accuracy evaluation color value is converted using the output characteristics of the target output device, and the target output is obtained. A predicted color value (y) that will be output from the apparatus is obtained, and a color difference between the predicted value (y ″) obtained by conversion using the conversion information and the predicted value (y) of the original accuracy evaluation color value. Ask for. This color difference is obtained for each accuracy evaluation color value, and an average value (average color difference) is calculated. Then, it may be determined whether or not the calculated average color difference is within a preset range. The accuracy evaluation color value may be substituted with the color value of the target output value pair or the color value of the actual output value pair.

  If the color difference (average color difference) is out of range, there is a problem with the conversion accuracy of the conversion information created by the creation unit 1, or there is a problem with the given target output value pair or actual output value pair. Show. It is useless to adjust the conversion information having such a problem. Therefore, the correction process is not performed, and the process ends abnormally, for example. In that case, it is preferable to notify that there is a problem in the conversion accuracy of the given target output value pair or actual output value pair or the conversion information to be created.

  If the accuracy determination unit 2 determines that the color difference (average color difference) is within a preset range, adjustment processing is performed. The important color to be adjusted is set in advance. For example, a color such as flesh color or gray may be set in advance so that the color conversion error affects the color appearance. Furthermore, a configuration set by the operator may be provided. FIG. 3 is an explanatory diagram of an example of an important color setting method. In the “profile automatic adjustment” item shown in FIG. 3A, several colors are presented in advance, and whether or not to adjust each color is set. In the “specific color adjustment” item, colors other than those set in the “profile automatic adjustment” item are set as important colors. As an example, when one of several setting methods shown in FIG. 3B is selected, for example, a selection screen shown in FIG. 3C is presented according to the setting method, and a color to be an important color may be selected. . Of course, a plurality of colors may be selected as important colors. It goes without saying that the method of setting an important color by the operator is not limited to this example. For example, various methods such as specifying a color on an image and extracting a representative color component of the specified area can be used. May be adopted. Further, when the operator sets an important color, how to adjust, what color range to adjust, and the like may be further set.

  The selection unit 3 selects, as a management color value, an accuracy evaluation color value that is in a predetermined color range including a preset important color. A set of accuracy evaluation color values is given in advance. Alternatively, the color value of the target output value pair or the color value of the actual output value pair may be used as the accuracy evaluation color value. FIG. 4 is a conceptual diagram of management color value selection. In FIG. 4, the important color is indicated by “heavy” in the circle, and the accuracy evaluation color value is indicated by a number in the circle. A predetermined color range is indicated by a broken-line circle. In this example, an area whose distance from the important color in the color space is d is a color range, and accuracy evaluations indicated as “1”, “2”, “3”, and “4” included in the color range. The color value is selected as the management color value, and the accuracy evaluation color value indicated as “5” is not the management color value.

  As a specific example, an important color is (c, m, y, k), an accuracy evaluation color value is (p, q, r, s), and a color range for selecting a management color value is important for each color component. Accuracy evaluation color values satisfying | c−p | <d, | m−q | <d, | y−r | <d, and | k−s | <d when the color components are within a range of ± d. May be selected as the management color value.

  Such a management color value is selected for each important color. FIG. 5 is an explanatory diagram of an example of the selected management color value. The example shown in FIG. 5 indicates that a plurality of management color values are selected when skin color, gray, and red are important colors.

  In addition, the color range including important colors when selecting the management color value is determined uniformly for each important color, and the color range corresponding to each important color is determined. Also good. For example, it may be determined in consideration of human sensitivity characteristics for important colors. The selected management color value is used without change even when iterative processing is performed.

  When the management color value is selected, the adjustment determination unit 4 determines whether adjustment is necessary for each important color based on the management color value. In the determination, the management color value selected by the selection unit 3 is converted by the conversion information created by the creation unit 1, and the color difference between the converted color and the color of the original management color value is obtained. It may be determined whether or not the set condition is satisfied. When obtaining the color difference, a value (LAB value) obtained by converting the management color value by the output characteristic of the target output device, and a value obtained by further converting the color value obtained by converting the management color value by the conversion information by the output characteristic of the actual output device From the (LAB value), the color difference may be calculated using the above equation (6). The output characteristics of the target output device and the output characteristics of the actual output device have been described with reference to FIG.

  The condition used for the determination is a condition for ending the adjustment for the important color so that the color reproduced by the actual output device for the important color does not look different from the color reproduced by the target output device. It is a condition to do. When color conversion is performed using conversion information, the appearance of the reproduced color may change depending on the color shift direction, so the management color values scattered around the important color are If it is shifted in a direction that does not affect the appearance of the image, no further correction is necessary.

  As a specific example, as a condition used for the determination when the skin color is an important color, the brightness of the converted color value after color conversion of the management color value by the conversion information is lighter than the brightness of the original management color value, For example, the hues of the management color value and the converted color value are within a predetermined range. In addition, as conditions used for the determination when gray is an important color, the difference in brightness between the management color value and the converted color value is within a predetermined range, and the saturation of the management color value is predetermined. It is below the value.

FIG. 6 is a flowchart illustrating a specific example of determination processing in the adjustment determination unit. FIG. 6 shows an example of determination processing in the adjustment determination unit 4 when the above-described skin color and gray are used as important colors. In this example, first, determination is made when the skin color is an important color. In S61, it is determined whether or not the difference ΔL ^* between the brightness component of the colorimetric value (here, L ^* ) corresponding to the skin color management color value and the brightness of the important color is greater than zero. If there is a management color value whose brightness corresponding to the management color value is equal to or less than the brightness corresponding to the important color, it is determined in S64 that the skin color is adjusted to be the important color. In this case, the adjustment for setting the skin color as an important color is performed in the brightness direction.

If the brightness is greater than the brightness corresponding to any of the management color value of the skin color also corresponds to the key color, in S62, the a ^* component and important colors of the a ^* component of colorimetric values corresponding to the skin color management color value difference .DELTA.a ^* it is determined whether the difference between [Delta] b ^* greater whether than the b ^* component and important colors of the b ^* component of the colorimetric values corresponding to the skin color management color value. If Δa ^* is greater than Δb ^* , the skin color will appear red, so it is determined in S64 that the skin color is adjusted to be an important color. If Δa ^* is equal to or less than Δb ^* , whether or not the difference Δθ between the hue angle of the colorimetric value corresponding to the skin color management color value and the hue angle of the important color is within a predetermined range in S63. Determine whether. If the hue angle difference Δθ is within a predetermined range, the adjustment is finished for the skin color. If the hue angle difference Δθ exceeds a predetermined range, it is determined in S64 that the skin color is adjusted to be an important color. If it is determined in S62 and S63 that the skin color is an important color, the adjustment in S64 is performed for the saturation and the hue direction.

Next, in this example, determination is made when gray is an important color. In S65, it is determined whether or not the difference ΔL ^* between the lightness component (here, L ^* ) of the colorimetric value corresponding to the gray management color value and the lightness of the important color is within a predetermined range. If the difference between the lightness component corresponding to the gray management color value and the lightness of the important color exceeds the predetermined range, it is determined in S67 that the adjustment to make gray the important color is performed. In this case, the adjustment with gray as an important color is performed in the lightness direction.

If no gray management color value has a difference between the lightness component corresponding to the management color value and the lightness of the important color exceeding the predetermined range, in S66, the gray management color value corresponds to the gray management color value. It is determined whether or not the a ^* component and b ^* component of the colorimetric values are within a predetermined range. If it is within the predetermined range, the adjustment for gray is finished. If the predetermined range is exceeded, it is determined in S67 that the adjustment is made with gray as an important color. In this case, adjustment with gray as an important color is performed in the saturation direction.

  In this determination processing example, the order of processing is performed in the order of adjustment of the lightness direction in which the skin color is an important color, adjustment of saturation and hue direction, adjustment of the lightness direction in which gray is an important color, and adjustment of the saturation direction. It will be. Of course, the order of this adjustment is not limited to this example. Further, the conditions when the skin color or gray is an important color are not limited to this example, and various conditions may be set. For other important colors, conditions corresponding to the respective important colors may be determined. The order of adjustment for each important color is not limited to this example. If it is determined that the adjustment is completed for any important color that satisfies the condition, the conversion information at that time may be output as the adjustment result.

  If it is determined that any important color is adjusted without satisfying the condition, an adjustment function is first set by the adjustment function setting unit 5 as an adjustment process. The adjustment function is set from the color difference between the color of the conversion color value obtained by converting the management color value according to the conversion information created by the creation unit 1 and the color of the original management color value. In order to calculate the color difference, for example, the converted color value is converted into a value in the LAB color space according to the output characteristics of the actual output device, and the management color value is also converted into a value in the LAB color space according to the output characteristics of the target output device. The color difference between them may be calculated.

  As described above, the appearance of the reproduced color changes depending on which direction the color is shifted. Since it can be seen in which direction the color difference is shifted, the adjustment function may be set by determining the adjustment direction for each important color.

  FIG. 7 is an explanatory diagram of an example of the adjustment function. As a specific example of setting the adjustment function, a case where skin color is an important color and brightness direction adjustment is performed will be described. If the skin color is an important color, the person's impression may change and appear when the color shifts to a darker direction than the original color. For this reason, when color conversion is performed based on the conversion information, conversion is preferably performed so that the brightness after conversion does not decrease. As an adjustment function therefor, if there is a management color value whose difference between the lightness corresponding to the conversion color value obtained by converting the management color value by the conversion information and the lightness corresponding to the original management color value is 0 or less, What is necessary is just to set the function which adjusts so that the lightness corresponding to the conversion information after conversion by conversion information about those management color values may become high.

  In the specific example shown in FIG. 7, for each management color value, a difference obtained by subtracting the lightness corresponding to the original management color value from the lightness corresponding to the converted color value is used as the lightness difference and corresponds to the management color value. The black circle is associated with the brightness. In this example, there is a management color value whose brightness difference is 0 or less. These management color values are adjusted so that the brightness difference obtained by subtracting the brightness corresponding to the management color value from the brightness corresponding to the converted color value is greater than zero. For this purpose, a curve indicating the relationship between brightness and brightness difference indicated by a thick line in FIG. 7 is considered, and a function for adjusting brightness so that the difference is 0 is set as an adjustment function on this curve. Simply, for a management color value whose brightness difference obtained by subtracting the brightness corresponding to the management color value from the brightness corresponding to the conversion color value is 0 or less, the brightness of the management color value may be set as the brightness corresponding to the conversion color value. But that alone does not guarantee color continuity. For this reason, here, a curve is set which has a minimum value for the lightness of the important color and increases as the distance from the lightness of the important color increases, and does not include a management color value having a smaller difference than this curve. An adjustment function may be set from this curve. Alternatively, for example, an adjustment function may be determined, and the coefficient of the adjustment function may be determined from the lightness corresponding to each management color value and the difference between the lightness and the lightness of the important color. A known method may be used as the coefficient determination method. For example, the difference between the lightness corresponding to the management color value and the lightness corresponding to the converted color value may be statistically processed. Alternatively, it may be set using various methods such as an operator setting with reference to variations in brightness difference.

In this example, an adjustment function for adjusting in the brightness direction is set when the skin color is an important color. In addition, in order to adjust the saturation direction, an adjustment function for adjusting the a ^* component, b ^* component, saturation component (C ^* component), hue component (θ component), and the like is set. Of course, an adjustment function combining the lightness component, the saturation component, and the hue component may be set. Further, for example, a weighting function is set for the above-described adjustment function for lightness by an a ^* component, a b ^* component, a C ^* component, a θ component, or the like, and the adjustment amount in the lightness direction by the above-described adjustment function is set to saturation or hue. You may set the new adjustment function controlled about the direction. For example, the weighting function in this case may be set to 1 in the a ^* and b ^* components or the C ^* and θ components of the important color, and may be set to a function that decreases as the distance from the important color increases. An area to which the adjustment function is applied may be set by this weight function. Of course, the weight function for the brightness direction and hue direction is set for the adjustment function for the saturation direction, or the weight function for the brightness direction and saturation direction is set for the adjustment function for the hue direction. It may be a function.

  Although the case where the skin color is set as the important color has been described here, the adjustment function may be set depending on which direction the important color is shifted in the case where the other color such as gray is set as the important color. When it is determined that adjustment is necessary for a plurality of important colors, an adjustment function corresponding to each important color is set.

  When the adjustment function is set, the adjustment unit 6 performs adjustment processing on the colorimetric values of the target output value pair based on them. The adjustment process may be performed by converting the colorimetric values of the target output value pair using the adjustment function to obtain the adjusted colorimetric values. FIG. 8 is an explanatory diagram of a specific example of adjustment by the adjustment function. In FIG. 8, the colorimetric values of the target output value pair are indicated by white circles, and the colorimetric values after adjustment are indicated by black circles.

  Here, it is assumed that adjustment is performed using an adjustment function set using a curve for lightness shown in FIG. In this adjustment function, the amount of adjustment becomes maximum at the lightness of the important color, and the amount of adjustment decreases as the value moves away from the lightness of the important color. The lightness of the important color is indicated by a broken line.

  An adjustment function is applied to the colorimetric values of each target output value pair, and adjustment according to the brightness is performed. The amount of adjustment is maximized in the lightness of the important color, and decreases as the value moves away from the lightness of the important color. Therefore, the amount of deviation between the white circle that is the colorimetric value before adjustment and the black circle that is the colorimetric value after adjustment decreases as the distance from the lightness of the important color increases.

  As described above, the adjustment unit 6 adjusts the colorimetric values of the target output value pair. At this time, since the adjustment amount decreases as the adjustment function moves away from the important color, the continuity of the color is not lost.

In this example, the case where the adjustment function for the lightness direction is applied is shown for the sake of simplicity. Of course, if an adjustment function for the a ^* and b ^* components or the C ^* and θ components is set. Then, adjustment is performed by applying an adjustment function for these components. Further, when using an adjustment function in which a weight function is set, for example, adjustment in the brightness direction is also performed according to the saturation, hue, and the like by the weight function. When adjustment is necessary for a plurality of important colors, adjustment for each important color is performed.

  After the adjustment by the adjustment unit 6, the target output value pair whose colorimetric value is adjusted is given to the creation unit 1, and the conversion information is recreated together with the actual output value pair. Since the colorimetric value of the target output value pair is adjusted, conversion information reflecting the adjustment is created. For example, in the adjustment using the skin color as an important color described above, the skin color brightness is adjusted in the direction of increasing the brightness, so the newly created conversion information uses a skin color that is more than in the case of color conversion using the previously created conversion information. It will be converted brighter. For example, when the conversion information creation method that performs weighting described in Patent Document 1 is used, only by changing the colorimetric values of one or several target output value pairs, the other target output value pairs are weighted. Adjustment may be negated. However, since the adjustment function is applied to the target output value pair in the adjustment process described above, the adjustment is reflected in the conversion information even if a conversion information generation method that performs weighting is used. Further, there is no need to add a target output value pair or an actual output value pair in order to create new conversion information.

  The newly created conversion information is subjected to adjustment processing after determination by the accuracy determination unit 2, but is selected in the first processing without selecting a new management color value in the selection unit 3 after the second time. Use managed color values. The adjustment determination unit 4 determines whether adjustment is necessary from the management color value. Since adjustment is performed by the adjustment unit 6, it may be determined that adjustment is not necessary. In this case, the newly created conversion information is output and the process ends. If there is an important color that is determined to need further adjustment by the adjustment determination unit 4, an adjustment function is set by the adjustment function setting unit 5, and the target output value is set by the adjustment unit 6 using the adjustment function. The pair of colorimetric values are adjusted, and the creation unit 1 creates the conversion information again. In this way, the process is repeated to create conversion information adjusted for important colors. Note that there are cases where the adjustment determination unit 4 does not determine that no adjustment is necessary even if the adjustment for each condition for each important color is repeated. In order to cope with such a case, an upper limit may be set for the number of repetitions, and when the number of repetitions reaches the upper limit, the adjustment process may be terminated and conversion information may be output. In that case, it may be notified to the request source of this processing that the output conversion information does not satisfy the condition.

  FIG. 9 is a block diagram showing an application example of an embodiment of the present invention. In the figure, 21 is a color conversion unit. The color conversion unit 21 performs color conversion of a given processing target image using the conversion information created in the embodiment of the present invention described above. The color-converted image may be output by the actual output device. The output image is adjusted so that the appearance of important colors is not different from that when output by the target output device. Therefore, the output of the target output device is reproduced by the actual output device as it is.

  FIG. 10 is an explanatory diagram of an example of a computer program, a storage medium storing the computer program, and a computer when the functions described in the embodiment of the present invention and the application example thereof are realized by the computer program. In the figure, 31 is a program, 32 is a computer, 41 is a magneto-optical disk, 42 is an optical disk, 43 is a magnetic disk, 44 is a memory, 51 is a CPU, 52 is an internal memory, 53 is a reading unit, 54 is a hard disk, and 55 is An interface 56 is a communication unit.

  You may implement | achieve the function of each part demonstrated by one Embodiment of the above-mentioned embodiment of this invention and its application example entirely or partially with the program 31 which a computer runs. In that case, the program 31 and data used by the program may be stored in a storage medium read by the computer. A storage medium is a signal of a corresponding signal that causes a change state of energy such as magnetism, light, electricity, etc., depending on the description content of the program, to the reading unit 53 provided in the hardware resource of the computer. The program description is transmitted to the reading unit 53 in a format. For example, a magneto-optical disk 41, an optical disk 42 (including a CD, a DVD, a Blu-ray disk, etc.), a magnetic disk 43, a memory 44 (including an IC card, a memory card, a flash memory, etc.) and the like. Of course, these storage media are not limited to portable types.

  The program 31 is stored in these storage media, and the program 31 is read from the computer by, for example, mounting these storage media on the reading unit 53 or the interface 55 of the computer 32, and the internal memory 52 or the hard disk 54 (magnetic disk) And the functions described in the above-described embodiment of the present invention and its application examples are realized in whole or in part. Alternatively, the program 31 is transferred to the computer 32 via the communication path, and the computer 32 receives the program 31 by the communication unit 56 and stores it in the internal memory 52 or the hard disk 54, and the CPU 31 executes the program 31. May be.

  In addition, various devices may be connected to the computer 32 via the interface 55. For example, a reception unit that receives information from the user may be connected, and the reception unit may specify designation of target output value pairs and actual output value pairs, for example, designation of important colors shown in FIG. You may comprise so that it may receive. When the configuration of the application example of the embodiment of the present invention is realized, an actual output device that outputs an image after color conversion may be further connected via the interface 55. Further, a reading device that reads an image to be processed may be connected. Further, the created conversion information may be stored in a storage medium via the hard disk 54 or the interface 55, or may be transferred to another device via a communication path via the communication unit 56. Further, for example, the program may be passed to a program that executes the function of the color conversion unit 21 shown in the application example.

  Of course, it may be partially configured by hardware, or all may be configured by hardware. Or you may comprise as a program which included all or one part of the function demonstrated by one Embodiment of this invention and its application example with other structures. Of course, when applied to other purposes, it may be integrated with the program for that purpose.

  DESCRIPTION OF SYMBOLS 1 ... Creation part, 2 ... Accuracy determination part, 3 ... Selection part, 4 ... Adjustment determination part, 5 ... Adjustment function setting part, 6 ... Adjustment part, 11 ... Target output device, 12 ... Actual output device, 21 ... Color conversion , 31 ... program, 32 ... computer, 41 ... magneto-optical disk, 42 ... optical disk, 43 ... magnetic disk, 44 ... memory, 51 ... CPU, 52 ... internal memory, 53 ... reading part, 54 ... hard disk, 55 ... interface 56: Communication unit.

Claims (4)

  A target output value pair that is a pair associated with a color value obtained by measuring a color output by giving a plurality of color values to the target output device and a plurality of colors for the actual output device The color when the target output device outputs the color value given from the actual output value pair that is the pair that is associated with the color value that gives the colorimetric value obtained by measuring the color that is output with the value is the actual color. Creation means for creating conversion information for conversion to color values to be reproduced by the output device, and important color set in advance among a plurality of evaluation color values that are color values for evaluation given in advance Selection means for selecting, as a management color value, the evaluation color value in a predetermined color range including the conversion color value obtained by converting the management color value according to the conversion information, and the management color value Adjustment function setting means for setting an adjustment function based on the color difference of the color and setting by the adjustment function setting means Adjusting means for adjusting the colorimetric value of the target output value pair by the adjusted function, wherein the creating means creates the conversion information from the adjusted target output value pair and the actual output value pair. A featured conversion information creation device.   Whether or not a color difference between the converted color value obtained by converting the management color value selected by the selection unit using the conversion information created by the creation unit and the management color value satisfies a preset condition. The conversion information created by the creation means is output when the first judgment means judges that the condition is satisfied by the first judgment means. Conversion information creation device. Whether within the color difference between the color of the evaluation color values of the color and the original case of converting the evaluation color values using the conversion information generated by the pre-Symbol creation means is set in advance 3. The conversion information creating apparatus according to claim 1, further comprising a second determination unit configured to determine whether or not the range is within a range.   A conversion information creating program for causing a computer to execute the function of the conversion information creating apparatus according to any one of claims 1 to 3.

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