JP4241266B2 - Color chart creation apparatus and color chart creation method - Google Patents

Description

  The present invention relates to a color chart creation device for creating color chart data for printing, which is necessary when creating a device profile describing the color characteristics of a printing press in order to match the color expressions of different input / output devices, and a color The present invention relates to a chart creation method and its program. In particular, the present invention relates to a color chart creation apparatus, a color chart creation method, and a program therefor, which are favorable for creating color chart data for printing with little influence on the accuracy of a device profile due to the printing state of a printing press.

  When creating printed matter, desk top publishing (DTP) using a computer is widely used. In DTP, a printed material is designed and edited using a display device or a computer, and a printed material is printed by a printing machine. At this time, it is important for the design, editing, and printing of publications to be efficient that the color appearance is the same even in different printing environments such as display devices and printing machines. Therefore, a color management system (CMS) is used as a technique for making the appearance of colors reproduced in different input / output devices the same. As data used in the CMS, a device profile which is data describing color characteristics of each device is used in order to match the color expressions of different input devices and output devices. An international organization formed for the purpose of standardizing the profile format is ICC (International Color Consortium), and a device profile described in accordance with this rule is an ICC profile.

For example, in order to create an ICC profile for a printing press, first, a color patch expressed in a device color space for a printing press, which is composed of a color patch composed of a combination of a plurality of color materials, is used for printing. Prepare color chart data. Subsequently, printing is performed using the color chart data in a printing machine for which an ICC profile is to be created. Then, an ICC profile is created by measuring a color patch on the printed color chart with a spectrophotometer (see, for example, Patent Document 1).
JP 2002-94821 A

  When creating an ICC profile, IT8 is widely used as a standard chart for output devices and input devices such as scanners, displays, and printers. In the color chart based on IT8, a plurality of color patches having different hues and lightness (luminance) are arranged, the arrangement order of the color patches is also determined, and the printing direction at the time of printing is also determined. .

  FIG. 17 is a diagram conceptually showing a color chart. As shown in FIG. 17, a color chart 96 compliant with IT8 includes a region 94 in which a plurality of color patches are regularly arranged. This area 94 is called a color patch group. The color patch group 94 also includes a portion 95 in which color patches of similar hues are arranged in a row with different brightness.

  By the way, as shown in FIG. 16, there are some printers in which a plurality of ink fountains 92 are arranged on a cylinder 91 of the printing machine, and printing is performed by supplying ink from the ink fountains 92. In the case of color printing, generally, yellow, magenta, cyan, and black (YMCK) inks are used, and inks of these colors are supplied from the ink fountain 92. It is generally difficult to uniformly supply ink of each color from the ink fountain 92. For this reason, the amount of ink supplied on the left and right sides of the printed matter is different, and the left and right colors may be different even with the same color, and the printing state is slightly different on the printing paper surface.

  Due to the difficulty in stabilizing the supply of ink from the ink fountain 92 in such a printing press, the color patches on the printed color chart contain errors in color and brightness. Furthermore, as described above, the color chart based on IT8 includes a portion 95 in which a plurality of color patches having the same hue and different lightness are arranged in the same direction as the printing direction. However, depending on the supply status of the ink by the ink fountain 92, there is a possibility that a large error is included. In this case, the accuracy of the created ICC profile is reduced. In particular, if there is a problem with the ink fountain 92 that supplies the ink necessary to print the portions 95 in which the color patches of similar hues are arranged in a row with different lightness, the problem of this ink fountain is generally found. In addition to being difficult to adjust, an ICC profile created based on a printed color chart may contain errors that cannot be used for color management.

  In the color chart creating method shown in Patent Document 1, it is only disclosed that the color patches are selected so that the color patches are uniformly distributed in the standard color space, and the ink is uniformly supplied from the ink fountain in the printing press. Does not take into account dealing with difficult things.

  The present invention has been made in view of such circumstances, and even if the amount of ink supplied in a printing press cannot be made uniform, it is possible to create a more accurate device profile even under such circumstances. An object of the present invention is to provide an apparatus, method and program for creating color chart data for printing.

  The present invention relates to color patch data required when creating a device profile describing the color characteristics of a printing press in order to match the color expressions of different input / output devices, and a plurality of colors indicating combinations of color materials A patch data storage means for storing patch data, a color patch by determining the arrangement order so that the arrangement order of the color patches is random, and reading and arranging the color patch data from the patch data storage means according to the determined arrangement order And a patch position determining means for generating color chart data for a printing press.

  As a result, even when it is difficult to make the ink supply amount uniform in the printing press, the color patches of the same series of colors are randomly arranged in the chart without being arranged in a line, and the same series of colors No problems occur in all color patch printing. That is, it is possible to reduce the influence of color misregistration based on the excess or deficiency of the ink supply amount with respect to color patches of the same series of colors, and as a result, it is possible to create a device profile with higher conversion accuracy.

  Further, in the above-described color chart creation apparatus, when a device profile of the target printing machine already exists, the device profile is used so that the achromatic colors in the standard color space independent of the apparatus are arranged almost evenly. A plurality of achromatic color patches, and an achromatic color patch adding means for adding the achromatic color patch to the patch data storage means, and the patch position determining means includes the achromatic color patch and includes the achromatic color patch. Random arrangement is performed and color chart data for the target printing press is created.

  If an error occurs in the vicinity of an achromatic color in the standard color space, the hue will be greatly different. In addition, it is more sensitive to luminance changes in achromatic colors than human visual characteristics. Therefore, by the above processing, achromatic color patches that are arranged almost evenly in the standard color space are added, and color chart data including them is added to the achromatic color that is sensitive to changes in human visual characteristics. The accuracy of conversion between the device space and the standard color space can be improved.

  In the color chart creating apparatus, the patch position determining unit may determine the size of the printing paper surface of the printing machine when the plurality of color patches cannot be printed on one color chart in the target printing machine. It includes a chart dividing means for randomly arranging the color patches so that all the color patches are printed in the corresponding number of color charts.

  In the color chart based on IT8, it is assumed that all color patches necessary for one color chart can be stored. Moreover, in order to measure a color patch with a spectrophotometer, each color patch needs a predetermined area. However, depending on the printing machine for which the device profile is to be created, there are cases where all the necessary color patches cannot be contained in one color chart due to the limitation of the size of paper that can be printed. In this case, by the above processing, the color patches are randomly arranged so that all the color patches are printed within the number of color charts corresponding to the size of the printing paper surface of the printing press. Therefore, a device profile can be created without being limited by the size of the printing paper surface of the printing press.

  Further, in the color chart creation device, a dummy patch, which is a color patch that may not be used when creating the device profile, is used as color chart data on at least a part of the periphery of the arranged color patch group. Further, a dummy patch adding means for adding is provided.

  In the periphery of the color patch group that requires measurement, there is usually no printed design, or other designs are arranged at a certain distance. For this reason, the amount of ink supplied tends to be insufficient at the periphery of the color patch group, which may cause color misregistration. Therefore, by providing a dummy patch around the color patch group to be measured by the above processing, it becomes easy to supply a necessary amount of ink to each color patch around the color patch group. Color shift can be reduced. As a result, it is possible to obtain color chart data for creating a highly accurate device profile.

  In the color chart creating apparatus, the dummy patch adding unit is a row of the color patch group in the same direction as the printing direction when the color chart is printed by the target printing machine, The dummy patch is added to the periphery of the arranged color patch group by arranging the same patch array as the endmost color patch array in parallel outside the endmost color patch array. .

  Thus, a dummy patch row having the same color as the color patch row located at the end of the color patch group is added in the color patch row in the same direction as the printing direction of the printing press. As a result, the required amount of ink can be efficiently supplied to the color patch array, and the color patch array located at the extreme end of the color patch group is printed in the same direction as the printing direction of the printing press. It becomes possible to prevent color shift at the time. As a result, it is possible to obtain color chart data for creating a highly accurate device profile.

  In the color chart creation apparatus, the dummy patch adding means is a direction orthogonal to a printing direction when the color chart is printed by the target printing machine, and is generally at the end of the color patch group. By arranging an achromatic color patch row, the dummy patch is added around the arranged color patch group.

  As a result, in the color patch row in the direction orthogonal to the printing direction of the printing press, a substantially achromatic dummy patch row is added around the color patch row located at the end of the color patch group. As a result, it is easy to supply ink of each color almost evenly at the start and end of printing of the color patch row to be measured, especially at the extreme end in the direction perpendicular to the printing direction of the printing press. It is possible to prevent color misregistration during printing of the color patch array. As a result, it is possible to obtain color chart data for creating a highly accurate device profile.

  Further, the color chart creation device further includes background color adding means for adding background color data to the color chart data so that the achromatic color is printed on the background portion where no color patch is arranged. It is characterized by.

  When the background of a color patch group or a patch group including a dummy patch applied around the color patch group is colorless, the color at the time of printing becomes insufficient particularly because the ink supply is insufficient around the patch group. There is a risk of misalignment. However, by adding an almost achromatic background color by this process, a predetermined amount of ink is stably supplied to each color around the patch group, and patch color misregistration can be prevented. become able to. As a result, it is possible to obtain color chart data for creating a highly accurate device profile.

  The present invention also provides color patch data necessary for creating a device profile describing the color characteristics of a printing press in order to match the color expressions of different input / output devices, and a plurality of combinations of color materials. The color patch data is stored in advance in the storage means of the computer, the calculation processing of the arrangement order is performed so that the arrangement order of the color patches is random, and the color patch data is read from the storage means and arranged according to the determined arrangement order. Is a color chart creation method for creating color chart data for a printing press by performing random arrangement processing of color patches.

  The color chart creation method also includes a method for causing a computer to perform other functions described in the color chart creation apparatus.

The present invention is also a program for causing a computer to create color chart data for a printing press, in which the computer describes the color characteristics of the printing press in order to match the color representations of different input / output devices. Color patch data required when creating a profile, and in a state of storing a plurality of color patch data indicating a combination of color materials, determine the arrangement order so that the arrangement order of the color patches is random, This is a program for causing a computer to execute a patch position determining function for randomly arranging color patches by reading out and arranging color patch data from a storage unit according to the determined arrangement order, and creating color chart data for a printing press.

  The program also causes the computer to execute functions for causing the computer to execute other functions described in the color chart creating apparatus.

  In the color chart creating apparatus, the color chart creating method, and the method according to the present invention, color chart data for a printing press capable of printing a color chart including randomly arranged color patches is created. As a result, even when it is difficult to make the ink supply amount uniform in the printing press, the color patches of the same series of colors are randomly arranged in the chart without being arranged in a line, and the same series of colors No problems occur in all color patch printing. That is, it is possible to reduce a decrease in printing accuracy based on an excess or deficiency of the ink supply amount for color patches of the same series of colors, and as a result, it is possible to create a device profile with higher accuracy.

  Hereinafter, a color chart creation device for creating color chart data for printing according to an embodiment of the present invention will be described with reference to the drawings. The following embodiments do not limit the invention described in the claims, and all combinations of features described in the embodiments are necessary for the solution means of the invention. Not necessarily.

  FIG. 1 is a diagram showing an overall apparatus configuration for creating a device profile using the color chart creating apparatus of the present invention. In FIG. 1, a color chart creation device 10, a print control device 30, and an ICC profile creation device 50 are included as devices (computers) necessary for creating a device profile.

  The color chart creation device 10 accumulates the color patch data 11 in a storage device in advance, and creates the color chart data 12 for printing that is necessary when the color chart is printed by the printing machine using the color patch data 11. . The color patch data 11 is data necessary for creating a device profile, and is data related to a plurality of color patches indicating combinations of color materials. The color material in a printing machine generally indicates four color inks of yellow, magenta, cyan, and black. A device profile means a file describing the color characteristics of different input / output devices such as a display device, a scanner, and a printing machine in order to match the color expression. Means a device profile for

  The device profile is information for converting from a device color space (Device Dependent Color) specific to the device to a standard color space (Device Independent Color) independent of the input / output device, from the standard color space to the device specific At least one of the information for conversion to the device color space is included. As a device profile, in this embodiment, an ICC profile described in accordance with the rules of an international organization (ICC) formed for the purpose of standardizing a device profile format is taken as an example. In the ICC profile, the device color space of the printing press is generally defined in the color system by YMCK, and the standard color space is CIE LAB (CIE 1976 L * a * b *) proposed by the CIE (International Lighting Commission). Is defined in the color system.

  In addition, when there is an ICC profile 13 of the target printing press, the color chart creating apparatus 10 also performs processing for creating the color chart data for printing 12 using the ICC profile to improve the accuracy of the ICC profile.

  The print control device 30 causes the printing machine 32, which is a target of ICC profile creation, to print the color chart 33 using the printing color chart data 12 created by the color chart creation device 10.

  The ICC profile creation device 50 includes a spectrophotometer 53 for measuring the CIE LAB value of each printed color patch. The ICC profile creation device 50 includes a patch measurement unit and an ICC profile creation unit as its functions. The patch measurement unit controls the spectrophotometer 53 to measure the CIE LAB value of each color patch to be measured in the color chart 33 printed by the printing machine 32 and accumulates it as measurement data 51. Further, as the measurement data 51, color values in the device color space of each color patch on the color chart are accumulated using the printing color chart data 12 or the like. The ICC profile creation unit associates the color values in the device color space of each color patch with the CIE LAB value measured by the spectrophotometer 53, and creates the ICC profile of the target printing machine 32. . The ICC profile creation unit can be realized by using commercially available software such as a profile maker of GretagMacbeth.

  Next, the processing flow of ICC profile creation by the apparatus configuration shown in FIG. 1 will be described with reference to FIG.

  First, the color chart creation device 10 uses the color patch data 11 to determine the arrangement of the color patches to be included in the color chart, and creates printing color chart data 12 that becomes printing data when printing with a printing press. Is performed (step S11).

  Next, the print control device 30 prints the color chart 33 on the printing machine 32 that is the target of ICC profile creation using the printing color chart data 12 created by the color chart creation device 10 (step S12). .

  Subsequently, the patch measurement unit of the ICC profile creation device 50 performs measurement regarding the color of the color patch to be measured in the color chart 33 printed by the printing machine 32 using the spectrophotometer 53, and obtains the measurement value. Utilizing this, the color values in the standard color space of each patch are accumulated as measurement data 51 (step S12). Note that dummy patches described later are added to reduce color misregistration during printing of a color patch to be measured, and need not be measured.

  Next, the ICC profile creation unit of the ICC profile creation apparatus 50 creates an ICC profile using the measurement data 51 (step S13). As described above, in the measurement data 51 for creating the ICC profile 52, the color values in the device space of each color patch on the color chart to be measured are also stored in advance. The ICC profile creation unit creates an ICC profile for each color patch by associating the color values in the standard color space with the color values in the device color space.

  Subsequently, when the process for increasing the accuracy of the ICC profile is performed using the created ICC profile 52 (step S14: Yes), the created ICC profile is used as the primary ICC profile 13 by the color chart creating apparatus 10. New color chart data for printing is created (step S10). On the other hand, when the process for increasing the accuracy of the ICC profile is not performed, or when the accuracy of the ICC profile is sufficiently increased and it is not necessary to perform the process for increasing the accuracy of the ICC profile again (step S14: No), the target The ICC profile for the printing press is completed. In order to improve the accuracy of the ICC profile shown in step S14, it is preferable to perform the loop processing returning to step 10 again at least once. In addition, the second and subsequent loop processing generally has a lower effect of increasing the conversion accuracy of the ICC profile than the first loop processing, and therefore the second and subsequent loop processing is performed depending on the required conversion accuracy of the ICC profile. Perform loop processing.

  The above is the processing flow until the ICC profile is created in the device configuration shown in FIG. The creation of the color chart shown in step 10 will be described in detail separately.

  Next, functions of the color chart creating apparatus 10 will be described. FIG. 3 is a diagram showing functional blocks of the color chart creating apparatus 10. In this figure, the same parts as those in the color chart creating apparatus 10 shown in FIG. As shown in FIG. 3, the color chart creating apparatus 10 includes an achromatic color patch adding unit 21, a patch position determining unit 22, a dummy patch adding unit 24, and a background color adding unit 25. The patch position determination unit 22 includes a chart division unit 23 as its function.

  If the ICC profile of the printing machine 32 already exists, the achromatic color patch adding unit 21 uses this ICC profile as the primary ICC profile 13 so that the achromatic colors are arranged almost evenly in the standard color space. A plurality of achromatic color patches expressed by the above are obtained, and the obtained color patches are added to the color patch data 11 as additional patch data.

  The patch position determination unit 22 determines the arrangement order so that the arrangement order is random with respect to the predetermined arrangement order of the color patches. Then, the patch position determination unit 22 reads the color patch data 11 from the storage device according to the determined arrangement order, arranges the color patches randomly on the color chart, and creates the color chart data 12. The patch position determination unit randomly arranges the color patches including the achromatic color patch when the data related to the achromatic color patch is added by the achromatic color patch addition unit 21. The color chart data 12 for the printing press is created.

  The chart division unit 23 included in the patch position determination unit 22 prints a color chart on the printing machine 32 when a plurality of necessary color patches cannot be printed on a single color chart when the printing machine 32 prints the color chart. Depending on the size, color patches are randomly arranged so that all necessary color patches are printed in a plurality of color charts.

  The dummy patch adding unit 24 applies a dummy patch, which is a color patch that does not need to be measured with a spectrophotometer, when creating an ICC profile to a part or all of the periphery of the arranged color patch group. Processing to add to the data 12 is performed.

  The background color adding unit 25 performs a process of adding background color data to the color chart data 12 so that an achromatic color is printed in the background portion where no color patch is arranged.

  As shown also in FIG. 1, the color chart creation device 10 stores or creates color patch data 10, printing color chart data 12, and a primary ICC profile 13. Here, the color patch data 10 includes data associating a number for identifying a color patch with a color value in the device space of the color patch. The color chart data for printing 12 is a file format that can be printed by a printing press, and is data including information on the position information of each color patch in the color chart and information on the color values in the device space of the color patch. The primary ICC profile 13 is an existing ICC profile for the printing press 32 or an ICC profile 52 created by the apparatus configuration shown in FIG. 1 in order to increase the accuracy of the ICC profile 52.

  Next, the operation of the color chart creation apparatus 10 will be described. FIG. 4 is a diagram showing an operation flow of the color chart creating apparatus.

  First, the color chart creating apparatus 10 determines whether an ICC profile for the printing press 32 already exists and whether processing for improving the accuracy of the ICC profile is performed using this ICC profile as the primary ICC profile 13 ( Step S20).

  When the process for improving the accuracy of the ICC profile is performed (step S20: Yes), the process proceeds to step S21. Otherwise (step S20: No), the process skips step S21 and proceeds to step S22. In the processing flow shown in FIG. 4, first, the case where there is no ICC profile of the printing machine 32 and the process proceeds to step S22 will be described.

  When the process for improving the accuracy of the ICC profile is not performed (step S20: No), the patch position determination unit 22 determines the arrangement order so that the arrangement order is random with respect to the initial arrangement order of the color patches. Made. Next, the color patch data 11 is read out according to the arrangement order determined from the storage device, and the color patches are randomly arranged by sequentially arranging them on the printing paper sheet expressed as digital data. Color chart data 12 serving as print data is created (step S22).

  Details of the processing of the patch position determination unit 22 for randomly arranging color patches shown in step S22 will be described with reference to FIG. As an initial color patch arrangement state, as shown by reference numeral 41 in FIG. 6, there are 924 color patches, patch numbers 000 to 923, and the patch positions and the corresponding patch numbers are the same. . In the color patch data 11, a combination of color materials is associated with each patch number as a color value, and the order of the initial color patch data is, for example, the arrangement of color patches defined by IT8. In order.

  In FIG. 5, a variable i indicating the number of times of random placement processing is initialized (step S31). Subsequently, two random numbers RND1 and RND2 are generated using a random number generation function or the like (steps S32 and S33). Here, the random number is generated as a real number in the range of 0 to less than 1.

  Next, the replacement location of the color patch position is determined, and the replacement of the color patch position using the patch number is performed (step S34). For example, when the number of color patches is “m”, the patch positions A and B for exchanging the positions of the color patches are obtained as follows.

A = INT (m × RND1)
B = INT (m × RND2)

  Here, the function INT () is a function that converts a real number into an integer, and the patch positions A and B become integers in the range of 0 to 923 by this function. For example, it is assumed that the patch position A is determined as “300” and the patch position B as “640” by the first color patch position replacement process. In this case, the positions of the patch number 300 and the patch number 640 at the position 300 and 640 of the color patch in the initial state indicated by reference numeral 41 in FIG. 6 are exchanged, and as a result of the replacement, the state indicated by reference numeral 42 in FIG. Become.

  The above steps S32 to S34 are repeated up to a predetermined patch position replacement count “n” (steps S35 and S36). The code | symbol 43 of FIG. 6 has shown an example of the arrangement | sequence order of the patch number after replacing n patch positions. By setting the number of replacements “n” to a sufficiently large value, the random arrangement order of the color patches is determined by the processing shown in FIG. When all the color patches are stored in one chart, the patch position determining unit 22 reads the color patch data 11 according to the arrangement order determined by the above processing, and the color patches are preliminarily arranged on the digital data. The color chart data 12 for the printing machine 3 is created by sequentially arranging them. FIG. 7 is a view showing an example of a color chart printed based on the color chart data created by the patch position determination unit 22. When the random arrangement order indicated by reference numeral 43 in FIG. 6 is used, for example, the arrangement position No. The color patch indicated by the patch number 601 is arranged in 0, the color patches are sequentially arranged, and the last arrangement position No. A color patch indicated by the patch number 192 is arranged at (m−1). In FIG. 7 and FIG. 11 described later, reference numeral 45 indicates a “color patch group” that is a group of color patches that require measurement by the spectrophotometer 53 on each color chart. In FIG. 7, some color patches have the same hatch pattern even if they are different due to space limitations.

  When printing a color patch on a color chart, it is necessary to measure each color patch with the spectrophotometer 53 after printing. Therefore, each color patch needs to be printed with a predetermined size. On the other hand, depending on the printing machine for which the ICC profile is to be created, there are cases where all the color patches to be measured cannot be printed on one sheet of paper. In this case, it is necessary to divide the color patches that need to be measured into a plurality of color charts. Therefore, in FIG. 4, when the color chart creating apparatus 10 prints the color chart with the printing machine 32, it is confirmed whether the printing machine 32 can print a plurality of necessary color patches on one color chart. Is performed (step S23). This determination is made, for example, by checking the specifications of the target printing machine 32.

  When it is necessary to divide and print the color patch into a plurality of color charts (step S23: Yes), the chart dividing unit 23 included in the patch position determining unit 22 determines the size of the printing paper surface of the printing machine 32. A process of randomly arranging the color patches is performed so that all the color patches are printed in a plurality of color charts (step S24). FIG. 8 is an example of a plurality of color chart images printed based on the plurality of color chart data created by the chart dividing unit 22. FIG. 8 shows an example divided into three color charts. When the random arrangement order indicated by reference numeral 43 in FIG. 6 is used, for example, the arrangement position No. 1 of the first color chart in FIG. The color patch indicated by the patch number 601 is arranged at 0, the color patches are arranged sequentially, and the last arrangement position No. 1 in the first color chart is arranged. A color patch indicated by the patch number 352 is arranged in a. In the second color chart, the color patch is similarly arranged, and the arrangement position No. 3 of the third color chart is set. In (b + 1), the color patch indicated by the patch number 738 is arranged, the color patches are sequentially arranged, and the last arrangement position No. No. 3 in the third color chart is arranged. In (m−1), the color patch indicated by the patch number 192 is arranged. As in the case shown in FIG. 7, a group of color patches that require measurement by the spectrophotometer 53 on each color chart, indicated by reference numeral 46 in FIG. 8, is also referred to as a “color patch group”.

  In FIG. 4, when it is not necessary to divide and print color patches into a plurality of color charts (step S23: No), or after being divided into a plurality of divided color charts in step S24, the dummy patch adding unit 24 Thus, a process of adding a dummy patch, which is a color patch that does not need to be a measurement target when creating an ICC profile, to part or all of the periphery of the arranged color patch group is performed on the color chart data 12. . An example of adding dummy patches to the color patch group by the dummy patch adding unit 24 will be described with reference to the drawings.

  FIG. 9 is a diagram showing an example of a color chart print image when dummy patch rows 61 and 62 are added to the color patch group 71 in the same direction as the print direction. 9 and other drawings, the color patch group 71 is the color patch group 45 when all the color patches necessary for one color chart are included as shown in FIG. 7, or as shown in FIG. One of the color patch groups 46 when all the necessary color patches are included in a plurality of color charts is shown in FIG. In the example of FIG. 9, the dummy patch adding unit 24 is one row in the color patch group 71 in the same direction as the printing direction of the target printing machine 32, and is the outermost color patch row 65 of the color patch group 71. In this example, dummy patch rows 61 and 62 including the same color patches as 68 are arranged in parallel near the outside of the respective color patch rows 65 and 68 to perform processing for adding dummy patches. With this processing, when the color patch row in the same direction as the printing direction is viewed, the outer dummy patch row 61 and the color patch row 65 become the same pattern patch row, and the other outer dummy patch row 62 and color patch row 68 Are patch rows with the same pattern.

  FIG. 10 is a diagram illustrating an example of a color chart print image when dummy patch rows 63 and 64 are added to the color patch group 72 in a direction orthogonal to the print direction. In the example of FIG. 10, the dummy patch adding unit 24 is in a direction orthogonal to the printing direction of the target printing machine 32, and in the vicinity of the endmost part of the color patch group 71, the dummy patch row 63 of approximately achromatic color, In this example, 64 is assigned to perform a process of adding a dummy patch. Here, the colors of the color patches included in the dummy patch rows 63 and 64 are the same color, and are, for example, half of the average value (average halftone%) of each color in the color patches included in the color patch group 71. A patch having (net%). As a result, the patches included in the dummy patch rows 63 and 64 are substantially achromatic.

  FIG. 11 is a diagram illustrating a print image example of a color chart when both the processes illustrated in FIGS. 9 and 10 are performed. In FIG. 11, the same parts as those in FIGS. 9 and 10 are denoted by the same reference numerals. In FIG. 11, compared to FIG. 10, not only the color patch group but also the added dummy patch rows 61 and 62, a dummy patch row made up of substantially achromatic patches so as to cover them. The difference is that 63 and 64 are added.

  Note that the method of adding dummy patches to the color patch group 71 by the dummy patch adding unit 24 is not limited to the above. For example, as shown in FIG. 12, two or more dummy patch rows including the same color patch as the outermost color patch row 65 of the color patch group 71 are provided as indicated by reference numerals 66 and 67, and the other outermost side is similarly provided. Two or more dummy patch rows including the same color patch as the color patch row 68 may be provided as indicated by reference numerals 69 and 97. Further, as shown in FIG. 13, the dummy patch having substantially achromatic color described in FIG. 10 may be added so as to surround the color patch group 71. Further, a dummy patch may be added by adding any color patch so as to surround the color patch group 71.

  After the dummy patch is added as described above, in FIG. 4, the background color adding unit 25 prints the color chart to be measured and the background portion on which the added dummy patch is not arranged, Background color data is added to the color chart data 12 so that an achromatic background color is printed (step S26). For example, as shown in FIG. 14, the background color is added so that the portions 74 other than the patches included in the color patch group 71 and the dummy patch group 73 are substantially achromatic. The background color is also added between the color patches by this processing. As an example of the background color to be added, each of the average values (average halftone%) of each color in the color patches included in the color patch group 71 is set to a value of 1/10 (halftone percentage). The background color does not need to be the entire printed chart, and may be added only so as to surround at least the arranged color patches and dummy patches with a predetermined width.

  Even if the process of step 21 in FIG. 4 is not performed, the color chart data 12 can be created by performing steps S22 to S26. By using the color chart data 12 and performing the processing shown in steps S11 to S13 shown in FIG. 2 using the apparatus configuration shown in FIG. 1, the ICC profile 52 for the printing press 32 can be created. In FIG. 2, when the ICC profile 52 created in this way is used to increase the accuracy of the ICC profile (step S14: Yes), the accuracy is improved using the ICC profile 52 created first. Processing is performed by the color chart creating apparatus 10 (step S21 in FIG. 4).

  In FIG. 4, when processing for improving accuracy is performed using the ICC profile 52 created first as the primary ICC profile 13 (step S <b> 20: Yes), the achromatic color patch adding unit 21 uses the primary ICC profile 13. In the standard color space, a plurality of achromatic color patches in the device space of the target printing press are obtained so that the achromatic colors are arranged almost uniformly. The obtained color patch is stored in the patch data 10 as additional color patch data (step S21). Hereinafter, this process will be described in more detail.

  FIG. 15 is a diagram for explaining the relationship between the color difference and the hue in the standard color space. Here, the CIE LAB (CIE 1976 L * a * b *) color system is taken as an example of the standard color space. In this color system, the “L *” axis indicates the change in brightness, the “a *” axis + direction is red, the “a *” axis − direction is green, and the “b *” axis + direction is yellow. The “b *” axis direction indicates blue, and the saturation increases with increasing distance from the L * axis at the origin position on the ab plan view shown in the figure. Further, the angle formed with respect to the origin of two points on the orthogonal projection plane viewed from the L * -axis direction in this color system indicates the degree of hue change (hue difference).

  In FIG. 15, for example, if a highly saturated color patch A is printed and measured with high accuracy, it is located at the point indicated by reference numeral 81 on the L * a * b * color system, but errors during printing, etc. Therefore, it is assumed that it is located at a point indicated by reference numeral 82. The angle formed with respect to the origin of the points indicated by reference numerals 81 and 82 at this time is defined as θ1. On the other hand, if an almost achromatic color patch B with low saturation is printed and measured with high accuracy, it is located at the point indicated by reference numeral 83 on the L * a * b * color system, but errors during printing, etc. Therefore, it is assumed that it is located at a point indicated by reference numeral 84. An angle formed with respect to the origin of the points indicated by reference numerals 83 and 84 at this time is defined as θ2. Here, it is assumed that the distance between the points 81 and 82 and the distance between the points 83 and 84 are equal. As shown in FIG. 15, in the case of the color patch A with high saturation, even if there is an error, the hue difference θ1 is relatively small. On the other hand, in the case of an almost achromatic color patch B, if there is an error, the hue difference θ2 becomes relatively large and may be perceived as a different color. In addition, from the human visual characteristics, humans can sensitively identify changes to achromatic brightness. For this reason, it is important to have a large number of measurement values relating to colors that are almost achromatic colors in the standard color space in order to improve the color conversion accuracy in the standard color space and the device color space.

  Therefore, the achromatic color patch adding unit 21 determines points at an equal interval on the achromatic color in the standard color space, that is, on the L * axis. For example, in the L * a * b * color system, a * = 0, b * = 0, and 10 points are determined at the same interval in the range of L * from 10 to 100. Next, the achromatic color patch adding unit 21 uses the primary ICC profile 13 to convert from a predetermined standard color space point (for example, 10 points) to a point in the device color space of the printing machine 32 (for example, 10 points). . The achromatic color patch adding unit 21 adds the point color patches (for example, 10 color patches) in the converted device color space to the color patch data 12 as color patches to be measured. The above is the processing of the achromatic color patch adding unit 21.

  In addition, when the achromatic color patch to be measured is added to the color patch data 11 by the achromatic color patch adding unit 21, the patch position determining unit 22 randomly arranges the color patches including this color patch. The color chart data 12 to be printed by the printing machine 32 is created (step S22).

  The operation of the color chart creating apparatus 10 has been described above.

  3 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed, thereby executing a printing machine. A color chart data creation process may be performed. Here, the “computer system” includes an OS and hardware such as peripheral devices. The “computer system” includes a WWW system having a homepage providing environment (or display environment). The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Further, the “computer-readable recording medium” refers to a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

  The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes designs and the like that do not depart from the gist of the present invention.

  For example, in the present embodiment, the creation of color chart data for a printing press is taken as an example. However, the present invention is not limited to this and can be applied to other input / output devices. In particular, it is favorable when applied to an input / output device in which a line-like error is likely to occur at a specific position during input / output.

  Further, in the present embodiment, the description has focused on a printing machine using ink, but the present invention is not limited to this. For example, it may be a printing machine that uses dyes, pigments, toners, etc. in addition to ink, and is particularly good when applied when line-like printing errors are likely to occur when using them.

  In this embodiment, the ICC profile is described as an example of the device profile, but the present invention is not limited to this. The device profile may be any device profile that can perform one-way or two-way color conversion at least between the device color space of the target apparatus and the standard color space. In the present embodiment, an example in which the color patch group fits in a square area is shown in FIGS. 7 to 14, but the present invention is not limited to this. When the color patch group does not fit in the square area, the dummy patch row and the dummy patch group provided around this area are basically provided along the color patch group area.

  Moreover, in this Embodiment, the example which processed each process part 21-25 shown in FIG. 4 is shown. However, the processing by all the processing units is not necessary, as long as at least the processing by the patch position determination unit 22 is included, and the processing by the other processing units 21 and 23 to 25 may be appropriately performed.

It is the figure which showed the whole apparatus structure for producing an ICC profile using the color chart production apparatus of this invention. FIG. 2 is a diagram showing a processing flow until an ICC profile is created in the apparatus configuration shown in FIG. 1. It is the figure which showed the functional block of the color chart production apparatus of this invention. It is the figure which showed the operation | movement flow of the color chart preparation apparatus. It is the figure which showed the detailed operation | movement flow of step S22 of FIG. It is a figure for demonstrating that the arrangement | sequence order of a color patch becomes random by the process shown in FIG. It is the figure which showed an example of the printing image of the color patch arranged at random. It is the figure which showed an example of the printing image when a color patch is arranged at random on a some color chart. It is a figure showing an example of a print image of a color chart when a dummy patch row is added to the color patch group in the same direction as the print direction. FIG. 6 is a diagram illustrating an example of a color chart print image when a dummy patch row is added to a color patch group in a direction orthogonal to the print direction. It is a figure showing an example of a print image of a color chart when a dummy patch is added around a color patch group. It is the figure which showed the other example of addition of the dummy patch at the time of adding a dummy patch to the periphery of a color patch group. It is the figure which showed the other example of addition of the dummy patch at the time of adding a dummy patch to the periphery of a color patch group. FIG. 6 is a diagram illustrating an example of a print image when an achromatic background color is added to a portion where color patches are not arranged on a color chart. It is a figure explaining the relationship between the color difference in a standard color space, and a hue. It is a figure for demonstrating the relationship between the cylinder of a printing machine, and an ink fountain. It is a figure for demonstrating the conventional color chart.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Color chart production apparatus 11 ... Patch data 12 ... Color chart data for printing 13 ... Primary ICC profile 21 ... Achromatic patch addition part 22 ... Patch position determination part 23 ... Chart dividing unit 24 ... Dummy patch adding unit 25 ... Background color adding unit 30 ... Print control device 32 ... Printer 50 ... ICC profile creation device 51 ... Measurement data 52 ... ICC profile 53 ... Spectrophotometer

Claims (6)

Color patch data required when creating a device profile that describes the color characteristics of a printing press that supplies ink from an ink fountain to match the color representation of different input / output devices. Patch data storage means for storing a plurality of color patch data indicating a combination of materials;
The arrangement order is determined so that the arrangement order of the color patches is random, the color patch data is read out and arranged from the patch data storage means according to the decided arrangement order, and the color patches are arranged randomly. Patch position determining means for creating chart data;
Dummy patch adding means for adding, to at least a part of the periphery of the arranged color patch group, a dummy patch that is a color patch that may not be used when creating the device profile, to the color chart data;
With
The dummy patch adding means is
A single row of said color patch groups of the print in the same direction at the time of printing a color chart on a printing press of interest, the same patch array color patch line most the outer side of said color patch group by arranged in parallel and adjacent to the outside of the color patch line to be the outermost, together with the addition of the dummy patches around the arranged color patch group,
The color patch group and the added dummy patch in a direction orthogonal to the printing direction when the color chart is printed by the target printing machine, and the added dummy patch, the color patch group , the added dummy patch, An achromatic color patch having a predetermined proportion of the average value of each color in the color patches included in the color patch group in parallel and adjacent to the outermost color patch of the color patches The dummy patch is added around the arranged color patch group by arranging the rows.
A color chart creating apparatus characterized by the above. The color chart creating apparatus is
When the device profile of the target printing machine already exists, the device profile is used to make the achromatic color in the standard color space independent of the apparatus equidistant on the axis indicating the change in brightness in the standard color space. A plurality of achromatic color patches to be arranged, and achromatic color patch adding means for adding the achromatic color patches to the patch data storage means,
2. The color according to claim 1, wherein the patch position determination unit randomly arranges color patches including the achromatic color patch and creates color chart data for the target printing machine. Chart creation device. The patch position determining means includes
When the target printing machine cannot print the plurality of color patches on one color chart, all the color patches are printed in the number of color charts corresponding to the size of the printing paper surface of the printing machine. The color chart creating apparatus according to claim 1, further comprising: a chart dividing unit that randomly arranges the color patches.   The background color data is printed so that the background portion where the color patch is not arranged is printed with an almost achromatic color having a predetermined ratio value with respect to the average value of each color in the color patch included in the color patch group. 4. The color chart creating apparatus according to claim 1, further comprising background color adding means for adding to the color chart data. A printing press that supplies ink from an ink fountain and performs printing in order to determine the arrangement order so that the arrangement order of the color patches is random, and to match the color expression of different input / output devices according to the determined arrangement order. Color patch data required when creating a device profile describing color characteristics, and by reading and arranging the color patch data from a patch data storage means for storing a plurality of color patch data indicating combinations of color materials A patch position determination procedure for randomly arranging color patches and creating color chart data for a printing press,
A dummy patch addition procedure for adding, to at least a part of the periphery of the arranged color patch group, a dummy patch that is a color patch that may not be used when creating the device profile, to the color chart data;
Have
The dummy patch adding procedure is:
A single row of said color patch groups of the print in the same direction at the time of printing a color chart on a printing press of interest, the same patch array color patch line most the outer side of said color patch group by arranged in parallel and adjacent to the outside of the color patch line to be the outermost, together with the addition of the dummy patches around the arranged color patch group,
The color patch group and the added dummy patch in a direction orthogonal to the printing direction when the color chart is printed by the target printing machine, and the added dummy patch, the color patch group , the added dummy patch, An achromatic color patch having a predetermined proportion of the average value of each color in the color patches included in the color patch group in parallel and adjacent to the outermost color patch of the color patches The dummy patch is added around the arranged color patch group by arranging the rows.
A method of creating a color chart. To a computer as a color chart creation device,
A printing press that supplies ink from an ink fountain and performs printing in order to determine the arrangement order so that the arrangement order of the color patches is random, and to match the color expression of different input / output devices according to the determined arrangement order. Color patch data required when creating a device profile describing color characteristics, and by reading and arranging the color patch data from a patch data storage means for storing a plurality of color patch data indicating combinations of color materials A patch position determination procedure for randomly arranging color patches and creating color chart data for a printing press,
A dummy patch addition procedure for adding, to at least a part of the periphery of the arranged color patch group, a dummy patch that is a color patch that may not be used when creating the device profile, to the color chart data;
And execute
The dummy patch adding procedure is:
A single row of said color patch groups of the print in the same direction at the time of printing a color chart on a printing press of interest, the same patch array color patch line most the outer side of said color patch group by arranged in parallel and adjacent to the outside of the color patch line to be the outermost, together with the addition of the dummy patches around the arranged color patch group,
The color patch group and the added dummy patch in a direction orthogonal to the printing direction when the color chart is printed by the target printing machine, and the added dummy patch, the color patch group , the added dummy patch, An achromatic color patch having a predetermined proportion of the average value of each color in the color patches included in the color patch group in parallel and adjacent to the outermost color patch of the color patches The dummy patch is added around the arranged color patch group by arranging the rows.
A program to make things happen.

Images