Program, plate generation method, and plate generation device

Abstract

To easily and appropriately generate spot color plates. [Solution] A program that causes a control device 14, which is a computer, to generate a plate that represents an image to be printed by a printing device 12, causes the control device 14 to perform an image input process in which an input image that will form the plate is input, and a plate generation process in which a plate is generated based on the input image, the printing device 12 prints using process color inks and spot color inks, and in the image input process, a color image in which opacity is set for at least some of the pixels is input as the input image, and in the plate generation process, a spot color plate corresponding to the spot color ink is generated based on the opacity set in the input image. A program characterized by:

Description

[Technical Field]

[0001] The present invention relates to a program, a plate generation method, and a plate generation device. [Background technology]

[0002] In recent years, printing devices that perform color printing using ink of multiple colors have been widely used. Also, printing devices that use ink of special colors (spot colors) other than process colors have been known (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-138089 Summary of the Invention [Problem to be solved by the invention]

[0004] When printing using multiple colors of ink in a printing device, it is usually necessary to specify the ink ejection positions for each color of ink. In this case, the ejection positions of each process color ink (color ink) are automatically determined based on the color image, for example, by software processing such as RIP processing that is executed by inputting the color image. In contrast, determining the ejection positions of spot color inks may require, for example, preparing an image corresponding to the spot color (hereinafter referred to as the spot color plate) separately from the color image. In this case, the spot color image must be created by a user, for example. More specifically, in this case, the user must create the spot color image by using image editing software or a function such as color replacement. This can result in problems such as a heavy user burden. Therefore, there has been a need for a method for easily and appropriately preparing spot color plates without placing a heavy burden on the user. Therefore, an object of the present invention is to provide a program, a plate generation method, and a plate generation device that can solve the above-mentioned problems. [Means for solving the problem]

[0005] The inventors of the present application have devised a method for preparing spot color plates without imposing a significant burden on the user, by generating spot color plates based on an input image that is input as the base image for process color plates. In this case, simply preparing a spot color plate involves, for example, generating a plate indicating that spot color ink is to be ejected at a uniform density over a rectangular image area (data size) in image data representing the process color input image, or generating a plate indicating that spot color ink is to be ejected at a uniform density over an ejection position (effective pixel) where ink of one of the process color colors is to be ejected. Furthermore, when a vector image is used as the input image, it is also possible to generate a plate indicating that spot color ink is to be ejected at a uniform density over an object position within the image. However, when generating spot color plates using these methods, the resulting plate corresponds to an operation of ejecting spot color ink so as to fill an area with a uniform density. Therefore, when generating spot color plates using these methods, it is usually difficult to generate a spot color plate that ejects ink at a desired density at a desired position. In response to this, the inventors of the present application came up with the idea of ​​using a color image in which opacity is set using an alpha channel or the like, and generating a spot color plate using the opacity information. With this configuration, for example, it is possible to easily and appropriately generate spot color plates that show a wider variety of ink ejection methods, without requiring much effort on the part of the user.

[0006]

[0010] Furthermore, the inventors of the present application have, through further intensive research, discovered the features necessary to achieve such effects and have arrived at the present invention. To solve the above problems, the present invention provides a program for causing a computer to generate plates representing images to be printed by a printing device, the program causing the computer to perform an image input process for inputting an input image that is an image that serves as a basis for the plates, and a plate generation process for generating the plates based on the input image, the printing device printing using process color inks that are basic colors of color expression and spot color inks that are inks of colors other than the process colors, the image input process inputting a color image in which opacity is set for at least some pixels as the input image, and the plate generation process generating spot color plates that are the plates corresponding to the spot color inks based on the opacity set for the input image.

[0007] With this configuration, for example, a computer executing this program can easily and appropriately generate a spot color plate based on an input image without requiring significant user effort. Furthermore, in this case, by using the opacity setting for the input image, a spot color plate corresponding to an operation of ejecting spot color ink using a method other than filling in at a uniform density can be appropriately generated as needed. Therefore, with this configuration, for example, spot color plates that represent various ink ejection methods can be easily and appropriately generated. This also makes it possible to more easily and appropriately generate, for example, a spot color plate corresponding to an operation of ejecting spot color ink at a desired density at a target position or an operation of ejecting spot color ink at partially different densities.

[0008] In this configuration, opacity can be considered, for example, as a parameter associated with transparency. Therefore, setting opacity for at least some pixels can be considered, for example, as information indicating opacity or transparency being associated with at least some pixels. In this configuration, the image input process may, for example, input an input image in which opacity is set in the alpha channel. This configuration allows, for example, an input image in which opacity is set for at least some pixels to be used appropriately. In the input image, opacity is set for at least some pixels in multiple levels, for example, three or more. In this case, the plate generation process generates, for example, a spot color plate based on the opacity, an image in which the color density of each pixel is expressed in three or more gradations. This configuration allows, for example, a spot color plate corresponding to an operation of ejecting spot color ink by a method other than filling with a uniform density to be more appropriately generated. In this case, the spot color plate can also be considered, for example, as a grayscale image corresponding to the spot color. The opacity is set for each pixel in multiple levels, for example, 16 or more levels (4 bits or more), preferably 256 or more levels (8 bits or more). Furthermore, in the plate generation process, a special color plate is generated based on this opacity, in which the value of each pixel (pixel value) is expressed in 16 or more levels (4 or more bits), preferably 256 or more levels (8 or more bits).

[0009] In this configuration, the inks of each process color may be, for example, inks of each basic color used for color expression using a subtractive color mixture method. Furthermore, the inks of each basic color may be, for example, inks of yellow (Y), magenta (M), cyan (C), and black (K). In this case, the spot colors may be considered, for example, colors other than YMCK (CMYK). Furthermore, the spot colors may be considered, for example, colors other than the basic colors used for color expression using a subtractive color mixture method. The spot colors may be considered, for example, colors treated as spot colors in the specifications of a printing device. In this configuration, the plate generation process further generates plates corresponding to each process color based on, for example, an input image. This configuration allows, for example, appropriate generation of plates corresponding to each ink color used in a printing device. In this configuration, the program further causes the computer to perform, for example, a raster image generation process that generates, based on plates, a raster image that matches the printing conditions of the printing device. In this case, in the raster image generation process, for example, a raster image for a spot color indicating the ejection position for ejecting the spot color ink is generated based on the spot color plate. Also, for example, a raster image indicating the ejection position for ejecting each color of ink is generated based on the plate corresponding to each color of process color. With this configuration, for example, the ejection position for each color of ink used in the printing device can be appropriately determined. More specifically, this program causes the computer to perform, for example, RIP processing as such a raster image generation process.

[0010] The features of the present invention can also be considered, for example, by focusing on the use of an alpha channel. In this case, the present invention can be considered, for example, as a program for causing a computer to generate plates representing images to be printed by a printing device, the program causing the computer to perform an image input process for inputting an input image, which is an image that serves as the basis for the plates, and a plate generation process for generating the plates based on the input image. The printing device prints using process color inks, which are the basic colors of color expression, and spot color inks, which are colors other than the process colors. In the image input process, a color image having an alpha channel is input as the input image, and in the plate generation process, a spot color plate, which is the plate corresponding to the spot color ink, is generated based on the value set in the alpha channel in the input image. This configuration also makes it possible to easily and appropriately generate spot color plates based on an input image. Furthermore, the present invention can also be configured, for example, by a plate generation method or plate generation device having the same features as those described above. In these cases, the same effects as those described above can be obtained. [Effects of the Invention]

[0011] According to the present invention, for example, a spot color plate can be easily and appropriately generated. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram illustrating a printing system 10 that uses a program according to an embodiment of the present invention. FIG. 1(a) shows an example of the configuration of the printing system 10. FIG. 1(b) shows an example of the configuration of a printing device 12 in the printing system 10. FIG. 1(c) shows an example of the configuration of a head unit 102 in the printing device 12. FIG. 1(d) shows an example of the configuration of a printed material produced by printing in the printing system 10. [Figure 2] 10 is a flowchart showing an example of an operation executed by the control device 14 in accordance with a RIP program. [Figure 3]3 is a flowchart showing an example of the operation of the control device 14 to generate a plate in step S104 in FIG. 2. [Figure 4] 4A and 4B are diagrams illustrating an example of an operation for generating a spot color plate based on an input image. Fig. 4A shows an example of an operation for generating a spot color plate based on the opacity set in the input image in this example. Fig. 4B shows an example of an operation related to a reference example that is different from the operation shown in Fig. 4A. DETAILED DESCRIPTION OF THE INVENTION

[0013] An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram illustrating a printing system 10 that uses a program according to an embodiment of the present invention. FIG. 1(a) shows an example of the configuration of the printing system 10. FIG. 1(b) shows an example of the configuration of a printing device 12 in the printing system 10. FIG. 1(c) shows an example of the configuration of a head unit 102 in the printing device 12. FIG. 1(d) shows an example of the configuration of a printed material produced by printing in the printing system 10. Except as described below, the printing system 10 and each part of the printing system 10 may have the same or similar features as known printing systems and their respective parts. In this example, the printing system 10 includes a printing device 12 and a control device 14. The printing device 12 is a device that performs printing under the control of the control device 14 in the printing system 10. For example, a known industrial inkjet printer or the like can be suitably used as the printing device 12. In this example, the printing device 12 is a color printer that performs color printing using inkjet printing with multiple colors of ink, and has a head unit 102, a base unit 104, a scan drive unit 106, and a control unit 110, as shown in FIG. 1(b), for example.

[0014] The head unit 102 is configured to eject ink onto a printing target medium 50 and includes multiple inkjet heads 202, as shown in FIG. 1C. In this example, the head unit 102 includes an inkjet head 202 for each process color and an inkjet head 202 for a specific spot color. With this configuration, the printing device 12 performs printing using the process color inks and the spot color inks. More specifically, in this example, the head unit 102 includes inkjet heads 202 for each of the process colors: yellow (Y), magenta (M), cyan (C), and black (K). The head unit 102 also includes an inkjet head 202 for a white (W) color as a spot color inkjet head 202. Process colors can be considered, for example, as basic colors for color expression. Furthermore, process colors can be considered to be, for example, colors used as base colors for color expression using a subtractive color mixture method in color printing performed by the printing device 12. Spot colors can be considered to be, for example, inks of colors different from the process color inks. Spot colors can be considered to be, for example, colors other than the base colors for color expression using a subtractive color mixture method. Spot colors can be considered to be, for example, colors treated as spot colors in the specifications of the printing device 12. In this example, spot colors can be considered to be, for example, colors other than YMCK (CMYK). In addition, in this example, the multiple inkjet heads 202 in the head unit 102 are aligned in a predetermined sub-scanning direction (X direction in the figure) preset in the printing device 12, and arranged in a main scanning direction (Y direction in the figure) perpendicular to the sub-scanning direction, as shown in the figure. Each inkjet head 202 has a nozzle row in which multiple nozzles are aligned at different positions in the sub-scanning direction. The inkjet heads 202 may be arranged in a different manner from the above in the head unit 102. Also, the head unit 102 may have inkjet heads 202 for colors different from those described above, for example.For example, the head unit 102 may have an inkjet head 202 for a spot color different from the above.

[0015] The base unit 104 is a platform-like member that supports the medium 50 at a position facing the head unit 102. The scan driver 106 is a driver that causes the head unit 102 to perform a scanning operation, moving relative to the medium 50. In this case, causing the head unit 102 to perform a scanning operation can also be considered, for example, as causing the inkjet head 202 in the head unit 102 to perform a scanning operation. In this example, the scan driver 106 causes the head unit 102 to perform a main scanning operation and a sub-scanning operation as the scanning operation. The main scanning operation can be considered, for example, as an operation of ejecting ink while moving in the main scanning direction relative to the medium 50 (scanning operation). The sub-scanning operation can be considered, for example, as an operation of moving in the sub-scanning direction relative to the medium 50. The scan driver 106 causes the head unit 102 to perform a sub-scanning operation between main scanning operations, thereby changing the portion of the medium 50 that faces the head unit 102 with each main scanning operation. The sub-scanning operation can also be considered as, for example, a feeding operation that feeds the medium 50 relative to the head unit 102.

[0016] The control unit 110 is, for example, the CPU of the printing device 12 and controls the operation of each unit of the printing device 12. In this example, the control unit 110 receives RIP-generated data, which is data generated by RIP processing (Raster Image Processing), from the control device 14 and controls the operation of each unit of the printing device 12 based on this RIP-generated data. According to this example, for example, the printing device 12 can appropriately print on the medium 50. In this case, for example, by using inks of each process color, color printing that draws a color image on the medium 50 can be appropriately performed. Furthermore, by using inks of special colors as needed, it is possible to perform, for example, a variety of printing. In addition to the above configuration, the printing device 12 may further have configurations that are the same as or similar to those of known printing devices. For example, the printing device 12 may further have a fixing unit that fixes ink to the medium 50.

[0017] The control device 14 controls the operation of the printing device 12 by supplying RIP-generated data generated by RIP processing to the printing device 12. In this example, the control device 14 is a computer such as a PC that executes a program for RIP processing (hereinafter referred to as a RIP program). The control device 14 generates RIP-generated data for causing the printing device 12 to print using, for example, spot-color inks, and supplies the RIP-generated data to the printing device 12. In this example, the RIP program is an example of a program that causes a computer to generate plates representing images to be printed by the printing device 12. The plates can also be considered, for example, as images to be processed for each ink color in the RIP process. The plates can also be considered, for example, as data representing images to be printed by the printing device 12 for the corresponding ink colors. In this example, the plates can be considered, for example, as representing an image to be printed by the printing device 12 using ink corresponding to the plates. The operation of the control device 14 to generate RIP-generated data will be described in more detail below.

[0018] In this example, the printing device 12 performs a printing operation based on the RIP-generated data received from the control device 14 to create a printed material in which multiple ink layers are formed on the medium 50, as shown in FIG. 1(d), for example. In the example shown in FIG. 1(d), the printing device 12 forms multiple ink layers, including a color layer 52 and a spot color layer 54, on the medium 50. In this case, the printing device 12 forms the color layer 52 and the spot color layer 54 on the medium 50 so that, for example, at least a portion of the color layer 52 overlaps with at least a portion of the spot color layer 54. In this example, the color layer 52 is an ink layer formed using process color ink. The color layer 52 can also be considered, for example, as an ink layer on which a color image is drawn. The spot color layer 54 is an ink layer formed using spot color ink. The spot color layer 54 can also be considered, for example, as an ink layer formed using only one spot color ink. As described above, the printing device 12 in this example uses white ink as the spot color ink. In this case, the special color layer 54 in FIG. 1(d) can be considered to be, for example, an ink layer (white layer) formed with white ink. In a modified configuration of the printing device 12, the printing device 12 may use ink of a special color other than white. In this case, the printing device 12 may form the special color layer 54 of a color other than white. More specifically, the printing device 12 may use, for example, a colorless, transparent clear ink or a primer ink used as a primer as the special color ink other than white. Furthermore, for example, a colored ink different from each of the process colors may be used as the special color ink. According to this example, for example, the printing device 12 can appropriately perform printing using the special color ink.

[0019] Next, the operation of generating RIP-generated data in the control device 14 will be described in more detail. FIG. 2 is a flowchart showing an example of the operation executed by the control device 14 in accordance with the RIP program. In this operation, the control device 14 first inputs an input image, which is an image to be processed (S102). In this example, the operation of step S102 is an example of the image input process and the operation of the image input stage. The input image can be considered, for example, as an image that serves as the basis for a plate in the operation of generating a plate described below. Also, in this example, the input image represents a print image, which is a color image to be drawn by the printing device 12 using process color inks. The input image representing the print image can be considered, for example, to mean that the content expressed in at least a portion of the input image substantially represents the content expressed in the print image. More specifically, the input image representing the print image can be considered, for example, to mean that the print image is substantially drawn based on the input image depending on the performance of the printing device 12.

[0020] In step S102 of this example, the control device 14 inputs, as the input image, a color image in which opacity is set for at least some of the pixels. In this case, the setting of opacity for at least some of the pixels can be considered, for example, as a value associated with opacity being associated with at least some of the pixels. Furthermore, opacity can be considered, for example, as a parameter associated with transparency. Therefore, transparency, for example, can be used as a value associated with opacity. In this case, the setting of opacity for at least some of the pixels can be considered, for example, as a value associated with opacity being associated with at least some of the pixels. Furthermore, the association of information indicating opacity or transparency with pixels can be considered, for example, as a value associated with pixels that is treated as information indicating opacity or transparency in image editing software. In this case, the image editing software may be software widely used in the printing industry, such as Photoshop (registered trademark) or Illustrator (registered trademark) sold by Adobe. More specifically, in this example, an image in which opacity is set in the alpha channel is used as the input image. With this configuration, for example, it is possible to appropriately use an input image in which opacity is set for at least some of the pixels.

[0021] In this example, opacity can be considered to be, for example, color information indicating the degree to which background colors are not transmitted through the input image. The alpha channel can be considered to be, for example, a channel indicating an alpha value, which is additional information for a pixel. The alpha channel, to which opacity is set, can be considered to indicate the transparency of each pixel of the input image, depending on the alpha value. For example, a multi-level value (e.g., 256 levels from 0 to 255, corresponding to 8 bits) is preferably used as the alpha value. In this case, the minimum alpha value indicates a completely transparent state, and the maximum alpha value indicates a completely opaque state. In this case, the alpha channel can be considered to indicate an image corresponding to the opacity, depending on the value set for each pixel. More specifically, the input image can be an image in a known image format with an alpha channel, such as a PNG image with an alpha channel or a TIFF image with an alpha channel. In this case, the operation of step S102 can be considered to be, for example, an operation of inputting a color image with an alpha channel as the input image. The opacity specified by the alpha channel can be considered to correspond to transparency information indicating the transparency of each pixel, for example. Therefore, the input image can be considered to be an image that includes transparency information as part of its image format.

[0022] Following the operation of step S102, the control device 14 generates plates corresponding to the colors of the inks used for printing based on the input image (S104). In this example, the operation of step S104 is an example of the operation of the plate generation process and plate generation stage. In step S104, the control device 14 generates plates corresponding to each of the process colors based on, for example, the input image. In this case, the control device 14 generates plates corresponding to each of the process colors by performing processing that is the same as or similar to a known method. More specifically, in this case, the control device 14 converts the input image into a color image that is expressed in a color system that matches the process colors by, for example, performing color conversion using a device profile (color profile) that matches the process color inks used in the printing device 12, and then performs plate separation processing on this color image that matches each of the process colors to generate plates corresponding to each of the process colors. In addition, when the printing device 12 is to print using spot color inks, in step S104 the control device 14 generates spot color plates that are plates corresponding to the spot color inks. If the input image has the above-described opacity settings, the control device 14 generates a spot color plate based on the opacity settings in the input image. More specifically, as described above, in this example, the control device 14 inputs, as the input image, a color image in which the opacity corresponding to the transparency information is set in the alpha channel. In this case, the control device 14 generates a spot color plate based on the value set in the alpha channel of the input image. This configuration allows the control device 14 to appropriately generate plates corresponding to, for example, each color of ink used in the printing device 12. According to this example, the control device 14 can easily and appropriately generate a spot color plate based on the input image, for example, without requiring significant user effort. Furthermore, in this case, by using the opacity settings in the input image, it is possible to appropriately generate a spot color plate corresponding to an operation of ejecting spot color ink using a method other than filling in a uniform density, as needed. This also makes it possible to easily and appropriately generate spot color plates that represent, for example, various ink ejection methods.More specifically, in this case, it is possible to more easily and appropriately generate, for example, a spot color plate corresponding to the operation of ejecting spot color ink at a desired density at a target position, or a spot color plate corresponding to the operation of ejecting spot color ink at partially different densities.

[0023] In this example, the control device 14 can be considered to function as a plate generating device that executes a predetermined plate generating method by executing a RIP program. The alpha channel can also be considered to represent an image corresponding to transparency information, for example, based on a value set for each pixel. Therefore, the control device 14 can be considered to generate a spot color plate based on the image represented by the alpha channel. In this case, the alpha channel can also be considered to be a spot color channel, for example. The operation of the control device 14 to generate plates in step S104 will be described in more detail later.

[0024] Following the operation of step S104, the control device 14 performs RIP processing based on the plates generated in step S104 to generate RIP-generated data (S106). In this example, the operation of step S106 is an example of a raster image generation process and a raster image generation stage. The raster image generation process and the raster image generation stage can be considered, for example, as a process and a stage for generating, based on plates, a raster image that matches the printing conditions of the printing to be performed by the printing device 12. More specifically, in step S106 of this example, the control device 14 specifies, for example, for each ink layer to be formed by the printing device 12, the printing conditions for the printing to be performed by the printing device 12 based on a user instruction. Then, the control device 14 generates, based on plates, a raster image that matches the printing conditions for each ink color used in printing by the printing device 12. In this case, the control device 14 generates, for example, a raster image that indicates the ejection positions for ejecting each color of ink based on plates corresponding to each color of process color. The control device 14 also generates a spot color raster image, for example, based on the spot color plate, indicating the ejection position of the spot color ink. This configuration allows, for example, the ejection position of each color ink used in the printing device 12 to be appropriately determined. The control device 14 also generates RIP-generated data by, for example, adding information related to control of the printing device 12 to the raster image generated for each color ink, as needed, and converting the data into data in a format processable by the printing device 12. In this case, the RIP-generated data can be considered to specify the ink ejection positions for each color ink used in the printing device 12. In this example, the RIP process can be considered, for example, to be a process of generating a raster image indicating the actual ink ejection positions from among the ejection positions set according to the printing resolution, based on an image input as a plate. The RIP process can also be considered, for example, to be a process of converting a digital image generated as a plate into a format understandable by the printing device 12. The RIP process can also be considered, for example, to be a process of generating a raster image according to printing conditions and converting the generated raster image into a command format understandable by the printing device 12, based on the plate.Depending on how the process is defined, the operations of steps S102 to S106 described above can be collectively considered to be RIP processing. In this case, the operation of step S106 can be considered to correspond to the operation of the raster image generation process performed in the RIP processing. Following the operation of step S106, the control device 14, for example, supplies RIP-generated data to the printing device 12, causing the printing device 12 to execute a printing operation based on the RIP-generated data (S108). According to this example, for example, the control device 14 can appropriately generate RIP-generated data based on an input image. This also allows the printing device 12 to appropriately print a print image corresponding to the input image on a medium. Furthermore, in this case, for example, the printing device 12 can appropriately form a spot color layer as needed.

[0025] Next, the operation of the control device 14 to generate a plate in step S104 will be described in more detail. FIG. 3 is a flowchart showing an example of the operation of the control device 14 to generate a plate in step S104 in FIG. 2. In this operation, the control device 14 first determines whether a spot color plate needs to be created (S202). In this case, the control device 14 determines whether a spot color plate needs to be created based on, for example, an instruction input by a user to a RIP program. Alternatively, for example, instructions indicating at least a portion of the printing content to be performed by the printing device 12 may be associated with the input image, and the control device 14 may read the instructions to cause the control device 14 to determine whether a spot color plate needs to be created. Then, if it is determined that a spot color plate needs to be created (S202, Yes), the control device 14 further determines whether transparency information is set in the input image (S204). In this example, the setting of transparency information in the input image can be considered to mean, for example, that opacity corresponding to the transparency information is set in the input image. The control device 14 determines that transparency information is present, for example, when the input image has an alpha channel and a value (alpha value) is set in the alpha channel at least at some pixel positions. If it is determined in step S204 that transparency information is present (Yes in S204), the control device 14 generates a spot color plate based on the transparency information (opacity) set in the input image (S206). In this case, the control device 14 generates a spot color plate based on the opacity, for example, corresponding to an operation of ejecting spot color ink using a method other than filling with a uniform density. The operation of the control device 14 to generate a spot color plate can also be considered, for example, as an operation of reading transparency information in the input image and converting the transparency information for the spot color to generate a spot color plate. The operation of generating a spot color plate by the control device 14 will be described in more detail later.

[0026] After generating the spot color plate in step S206, the control device 14 generates plates (CMYK plates) corresponding to each of the process colors, for example, using the same or similar method as known in the art (S208). In this example, the control device 14 combines the plates by associating the spot color plate generated in step S206 with the plates corresponding to each of the process colors generated in step S208 (S210). This completes the plate generation operation of the control device 14. In this example, combining the plates can be considered, for example, associating multiple plates corresponding to different colors as plates corresponding to a single printing unit. A single printing unit can be considered, for example, as a unit corresponding to a printed product that is an independent printing result. In this example, following step S208, the control device 14 performs RIP processing in step S106. In this RIP processing, the control device 14 generates a raster image for each ink color based on the ink plates for each ink color combined in step S210. Therefore, combining the plates can be thought of as combining a plurality of plates as the processing targets of the RIP process performed in step S106, for example.

[0027] Furthermore, if it is determined in step S202 that a spot color plate does not need to be created (S202, No), the control device 14 skips steps S204 and S206 and proceeds to step S208. Furthermore, if it is determined in step S204 that transparency information is not set in the input image (S204, No), the control device 14 generates a spot color plate using another method without using transparency information (S212) and proceeds to step S208. In this case, the control device 14 generates a spot color plate using, for example, a method identical to or similar to a known method. More specifically, in this case, the control device 14 generates a spot color plate indicating that spot color ink is to be ejected at a uniform density based on the input image. Examples of such a spot color plate include a spot color plate indicating that spot color ink is to be ejected at a uniform density over a rectangular image area, a spot color plate indicating that spot color ink is to be ejected at a uniform density over effective pixels, and the like. In step S212, the control device 14 may also input an image for a spot color separately from the input image and generate a spot color plate based on this image. In this case, the control device 14 uses, for example, an image created by the user using image editing software as the image for the spot color. According to this example, the control device 14 can appropriately generate plates corresponding to, for example, each color of ink used in the printing device 12.

[0028] Next, the operation of generating a spot color plate in the control device 14 will be described in more detail. FIG. 4 is a diagram showing an example of the operation of generating a spot color plate based on an input image. FIG. 4(a) shows an example of the operation of generating a spot color plate based on the opacity set in the input image in this example. As described above, in this example, an image in which opacity is set in at least some pixels is used as the input image input to the control device 14. The control device 14 then generates a spot color plate based on the opacity set in the input image. As a result, the control device 14 generates a spot color plate corresponding to an operation of ejecting spot color ink using a method other than filling with a uniform density, as shown in FIG. 4(a), for example. More specifically, as described above, in this example, a color image in which opacity is set in the alpha channel is used as the input image. In this case, a color and opacity are set for each pixel in the input image, as shown in a simplified manner on the left side of FIG. 4(a). In this figure, each square represents a pixel (color pixel) in the input image. The hatched patterns in the squares indicate the color to be set for the pixel. In this case, squares without a hatched pattern are pixels for which no color is set. In this diagram, for example, it can be thought that the different colors set for the pixels are expressed by the different hatched patterns. The numerical values ​​shown as percentages in some of the squares are transparency information corresponding to the opacity.

[0029] In the illustrated example, the transparency information value is 0% for the most opaque state and 100% for the most transparent state. In contrast, the opacity set as the alpha value in the alpha channel indicates, for example, a completely transparent state at its minimum value and a completely opaque state at its maximum value. Therefore, the transparency information values ​​shown in the figure can be considered to correspond to, for example, the inverse values ​​of the opacity gradation expressed in a predetermined number of gradations in the alpha channel. Also, in FIG. 4, for convenience of illustration and explanation, the transparency information is shown as a percentage value. In contrast, as explained above, the opacity set in the alpha channel uses a predetermined multi-gradation value (gradation value), such as a 256-level value corresponding to 8 bits. In this case, the gradation can be considered, for example, as a color step in a gradation that represents the shade of a color. In this case, the transparency information can also be considered to actually have the same number of gradations as the opacity. Furthermore, when the opacity set in the input image is considered more generally, it can be considered that the opacity is set for at least some pixels in the input image in multiple steps, for example, three or more steps, and the opacity is set for pixels in multiple steps, for example, 16 or more steps (4 bits or more), preferably 256 or more steps (8 bits or more).

[0030] FIG. 4(a) also shows a simplified view on the right side of at least a portion of the spot color plate generated by the control device 14 based on the input image shown on the left. In this figure, each square represents a pixel in the spot color plate. The percentage values ​​shown in some squares represent pixel values ​​set for the pixels corresponding to the squares. These pixel values ​​can be considered to represent, for example, the color density set for the pixel. FIG. 4(a) also shows an example in which the pixel values ​​of each pixel in the spot color plate are set to the same value as the transparency information set for the corresponding pixel in the input image. In this case, the pixel values ​​of each pixel in the spot color plate can also be considered to be, for example, the inverse of the opacity gradation set in the alpha channel of the input image. The pixel values ​​of each pixel in the spot color plate may be different from the transparency information in the input image depending on the purpose of the spot color layer, etc. In this case, the control device 14 generates a spot color plate in which the pixel value of each pixel is set to a value with a predetermined number of gradations, for example, based on the transparency information (opacity) in the input image. More specifically, the control device 14 may set, as the pixel value of each pixel of the spot color plate, a value that does not invert the opacity gradation set in the alpha channel of the input image. Furthermore, the control device 14 may set, as the pixel value of each pixel of the spot color plate, a value that inverts the opacity gradation, or a value that is a preset adjustment of the value that does not invert the opacity gradation. In this case, the adjustment may involve, for example, gamma correction. This configuration allows for more appropriate generation of a spot color plate according to the intended use of the spot color layer, for example, based on transparency information in the input image.

[0031] Also, in FIG. 4, for convenience of illustration and explanation, the pixel values ​​of the spot color plate are also shown as percentage values. In actual operation, for example, a predetermined multi-tone value is used as the pixel value of the spot color plate. In this case, the control device 14 generates a spot color plate in which the pixel value of each pixel is expressed, for example, in 16 or more levels (4 bits or more), preferably 256 or more levels (8 bits or more), based on the transparency information of the input image. More specifically, in this example, the control device 14 sets, for example, 256 levels corresponding to 8 bits as the pixel value of the spot color plate. In this case, the control device 14 can be considered to generate an image in which the color density of each pixel is expressed in three or more levels, based on the opacity set in the input image. With this configuration, for example, a spot color plate corresponding to an operation of ejecting spot color ink by a method other than filling with a uniform density can be appropriately generated. In this case, the spot color plate can also be considered, for example, as a grayscale image corresponding to the spot color. The spot color plate can be considered to indicate, for example, the ink duty of the spot color for each pixel. Furthermore, the operation of the control device 14 to generate such a spot color plate can also be considered to be, for example, an operation to adjust the ink duty of the spot color plate based on the opacity set in the alpha channel of the input image.

[0032] As described above, in this example, the control device 14 generates a spot color plate using the opacity set as an alpha value in the alpha channel of the input image. However, if one simply considers preparing a spot color plate, it is also possible to generate the spot color plate based on the color image represented by the input image without using opacity, as shown in FIG. 4(b). FIG. 4(b) illustrates an example of an operation for generating a spot color plate without using the opacity set in the input image, which is different from the operation shown in FIG. 4(a). In FIG. 4(b), the left side shows the same input image as in FIG. 4(a). In this case, at least some pixels in the input image are set to opacity, as indicated by the transparency information shown as a percentage in the figure. However, in this example, the transparency information of the input image is not reflected in the spot color plate, as shown on the right side of the figure. In FIG. 4(b), the right side shows a simplified view of at least a portion of the spot color plate generated in this example.

[0033] More specifically, when generating a spot color plate in the operation of this reference example, the control device 14, for example, identifies effective pixels, which are pixels in the input image that are set to a certain color, and assigns a predetermined constant pixel value to pixels of the spot color plate that correspond to the effective pixels of the input image. For example, in the left diagram of FIG. 4(b), the pixels marked with a hatched pattern are effective pixels. In this case, the control device 14 assigns a pixel value corresponding to the value indicated as 100% in the right diagram to pixels of the spot color plate that correspond to the effective pixels of the input image. Even with this configuration, it is possible to generate a spot color plate corresponding to the input image, for example. Another possible method for generating a spot color plate without using opacity is to assign a predetermined constant pixel value to all pixels included in an image area corresponding to the entire input image. Even with this configuration, it is possible to generate a spot color plate corresponding to the input image, for example. Furthermore, the method for generating a spot color plate without using opacity may also be applied to an input image to which no opacity is set. However, when spot color plates are generated using these methods without using opacity, a spot color plate that indicates, for example, the ejection of spot color ink at a uniform density is generated. Therefore, in this case, it is difficult to generate spot color plates that indicate various ink ejection methods. Such spot color plates can also be considered, for example, as plates corresponding to binary images. In contrast, in this example, as shown in FIG. 4(a), the pixel values ​​set for the pixels of the spot color plate can be appropriately varied for each pixel. This also makes it possible to appropriately generate spot color plates that indicate, for example, various ink ejection methods.

[0034] Next, supplementary explanations and variations of the configuration described above will be provided. As described above, in this example, a spot color plate can be generated automatically by generating it based on the opacity set in the alpha channel of an input image, for example, without the user having to separately prepare an image or the like that serves as the basis for the spot color plate. This also allows the spot color plate to be generated easily and appropriately without the user having to manually create spot color plate data using image editing software. Therefore, this example allows the spot color plate to be generated easily and appropriately without requiring much effort on the part of the user. Furthermore, in this example, the control device 14 generates the spot color plate according to the RIP program, eliminating the need for image editing software separate from the RIP program. Furthermore, in this example, generating a spot color plate based on opacity allows the easy and appropriate generation of a spot color plate corresponding to an operation of ejecting spot color ink in a manner other than filling with a uniform density, as needed. This also allows the easy and appropriate generation of spot color plates that represent various ink ejection methods, for example. Therefore, according to this example, for example, it is possible to more appropriately generate a spot color plate that matches the design to be expressed in the printed matter.

[0035] As explained above, in this example, the printing device 12 is a color printer that performs color printing using an inkjet method with multiple colors of ink. In this case, the colors expressed by the inks used in the printing device 12 can be considered, for example, as colors (object colors) that result from light reflecting off, absorbing, or transmitting light from an object. When, as in this example, basic color inks for subtractive color mixing are used as the process color inks, it may be necessary to form a background ink layer. For example, when printing on a translucent medium such as film, acrylic, or glass, or a colored medium, it may be necessary to form a background light-reflective ink layer. In this case, the printing device 12 forms a white layer, for example, a white ink layer, as a special color layer corresponding to such an ink layer. Depending on the design to be expressed in the printed matter, it may be desirable to form the white layer using a method other than filling in the white layer with a uniform density. More specifically, for example, when attempting to express a color image with a sense of transparency in a color layer, forming a background ink layer, such as a white layer, using a uniform density fill method may result in the transparency of the color image being lost due to the influence of the background. Furthermore, in this case, the background color may become overly prominent, creating an unnatural appearance and affecting the quality of the printed material. Furthermore, when forming an ink layer with a uniform density, for example, the background ink layer may cover the medium, making it difficult to print while taking advantage of the medium's color. In contrast, according to this example, as described above, it is possible to easily and appropriately generate a spot color plate corresponding to the operation of ejecting spot color ink using a method other than a uniform density fill method, as needed. Furthermore, this allows for more appropriate formation of a spot color layer that is less likely to create an unnatural appearance, for example, when attempting to express transparency in at least a portion of a color image to be drawn on a printed material or when utilizing the color of the underlying medium.

[0036] As described above, the printing device 12 can be, for example, an industrial inkjet printer. In this case, an inkjet printer for various applications using special color inks can be used as the industrial inkjet printer. More specifically, a DTF (Direct to Film / Digital Transfer Film) printer that prints on a transfer film can be used as an example of such an inkjet printer. In this case, the printing device 12 forms a color layer on the transfer medium, and then forms a white layer on top of the color layer to serve as the special color layer. By forming such a white layer, for example, it is possible to appropriately form an ink layer that serves as the background of the color layer after transferring the image from the transfer medium to the transfer medium. This also allows, for example, the color expression in the color layer to be appropriately suppressed while appropriately suppressing the influence of the color of the transfer medium. Furthermore, in this case, forming a white layer on the color layer can also improve the adhesion of, for example, transfer powder (hot melt powder). Therefore, with this configuration, the transfer powder can be appropriately applied, for example, to positions where thin lines are expressed in the color layer.

[0037] As described above, in this example, the input image is, for example, an image in which opacity corresponding to transparency information is set in the alpha channel. In this case, the input image can also be considered as, for example, data in a file format in which color information representing a color image and transparency information are set for each pixel. In this case, information representing colors in various known formats can be suitably used as the color information. More specifically, the color information in the input image can be, for example, RGB information, which is information representing colors in the RGB color system. In this case, the control device 14 generates, for example, CMYK plates corresponding to each color of the process color based on the RGB information, and generates spot color plates based on the transparency information. The color information in the input image can also be, for example, CMYK information, which is information representing colors in the CMYK color system (YMCK color system). In this case, the control device 14 generates, for example, CMYK plates based on the CMYK information, and generates spot color plates based on the transparency information. The input image can also be, for example, an image in which both RGB information and CMYK information are set as color information. In this case, the control device 14 generates a CMYK plate based on at least one of RGB information and CMYK information, and generates a spot color plate based on transparency information, for example.

[0038] In addition, in a modified configuration and operation of the printing system 10, it is also possible to set information other than opacity in the alpha channel of the input image. In this case, the control device 14 generates a spot color plate based on the information set in the alpha channel, for example, in the same or similar manner as the operation described above. Even with this configuration, it is possible to appropriately generate a spot color plate, for example. It is also possible, for example, to represent an image created by a user using image editing software in the alpha channel of the input image. In this case, the user may have to take the time and effort of creating the image in advance, but the subsequent process of generating the spot color plate can be performed using the same procedure as when using an input image with transparency information set in the alpha channel. Therefore, with this configuration, for example, in a printing system 10 using an input image with transparency information set in the alpha channel, it is possible to specify the position where spot color ink is to be ejected more directly and in detail as needed. This also allows, for example, the printing system 10 to appropriately generate a wider variety of spot color plates. [Industrial Applicability]

[0039] The present invention can be suitably used in, for example, a program that causes a computer to generate a plate representing an image to be printed by a printing device. [Explanation of symbols]

[0040] 10 printing system, 102 head unit, 104 base unit, 106 scan drive unit, 110 control unit, 12 printing device, 14 control device, 202 inkjet head, 50 medium, 52 color layer, 54 special color layer

Claims

1. A program that causes a computer to generate a plate representing an image to be printed by a printing device, an image input process for inputting an input image that is an image that is the basis of the plate; a plate generation process for generating the plate based on the input image; causing the computer to perform the printing device performs printing using process color inks, which are basic colors for color expression, and special color inks, which are inks of colors other than the process colors; In the image input process, a color image in which opacity is set for at least some pixels is input as the input image; A program characterized in that, in the plate generation process, a spot color plate, which is the plate corresponding to the spot color ink, is generated based on the opacity set in the input image.

2. 2. The program according to claim 1, wherein the plate generating process further generates the plates corresponding to each of the process colors based on the input image.

3. further causing the computer to perform a raster image generation process for generating a raster image based on the plate, the raster image being matched to the printing conditions of the printing to be performed by the printing device; In the raster image generation process, generating a raster image for the spot color that indicates an ejection position for ejecting the spot color ink based on the spot color plate; 3. The program according to claim 2, further comprising generating a raster image indicating ejection positions for ejecting ink of each color based on a plate corresponding to each of the process colors.

4. 2. The program according to claim 1, wherein the input image has the opacity set in an alpha channel in the image input process.

5. In the input image, the opacity is set for the at least some pixels in a plurality of stages of three or more stages; 2. The program according to claim 1, wherein, in the plate generation process, an image is generated as the spot color plate, which indicates the color density of each pixel in three or more gradations based on the opacity.

6. A plate generation method for generating a plate representing an image to be printed by a printing device, comprising: an image input step of inputting an input image that is an image that is the basis of the plate; a plate generation step of generating the plate based on the input image; Equipped with the printing device performs printing using process color inks, which are basic colors for color expression, and special color inks, which are inks of colors other than the process colors; In the image input step, a color image in which opacity is set for at least some pixels is input as the input image; A plate generation method characterized in that, in the plate generation step, a spot color plate, which is the plate corresponding to the spot color ink, is generated based on the opacity set in the input image.

7. A plate generating device that generates a plate representing an image to be printed by a printing device, an image input process for inputting an input image that is an image that is the basis of the plate; a plate generation process for generating the plate based on the input image; and the printing device performs printing using process color inks, which are basic colors for color expression, and special color inks, which are inks of colors other than the process colors; In the image input process, a color image in which opacity is set for at least some pixels is input as the input image; a plate generating device that generates a spot color plate, which is the plate corresponding to the spot color ink, based on the opacity set in the input image in the plate generating process;

8. A program that causes a computer to generate a plate representing an image to be printed by a printing device, an image input process for inputting an input image that is an image that is the basis of the plate; a plate generation process for generating the plate based on the input image; causing the computer to perform the printing device performs printing using process color inks, which are basic colors for color expression, and special color inks, which are inks of colors other than the process colors; In the image input process, a color image having an alpha channel is input as the input image; A program characterized in that, in the plate generation process, a spot color plate, which is the plate corresponding to the spot color ink, is generated based on a value set in the alpha channel in the input image.

9. A plate generation method for generating a plate representing an image to be printed by a printing device, comprising: an image input step of inputting an input image that is an image that is the basis of the plate; a plate generation step of generating the plate based on the input image; Equipped with the printing device performs printing using process color inks, which are basic colors for color expression, and special color inks, which are inks of colors other than the process colors; In the image input step, a color image having an alpha channel is input as the input image; A plate generation method characterized in that, in the plate generation step, a spot color plate, which is the plate corresponding to the spot color ink, is generated based on the value set in the alpha channel in the input image.

10. A plate generating device that generates a plate representing an image to be printed by a printing device, an image input process for inputting an input image that is an image that is the basis of the plate; a plate generation process for generating the plate based on the input image; and the printing device performs printing using process color inks, which are basic colors for color expression, and special color inks, which are inks of colors other than the process colors; In the image input process, a color image having an alpha channel is input as the input image; a plate generating device that generates a spot color plate, which is the plate corresponding to the spot color ink, based on a value set in the alpha channel in the input image in the plate generation process.

Images