Print data processing method, print data processing device, printing system, and print data processing program

Abstract

To reduce a time required in producing final print data without deteriorating a printing quality, in performing printing using process-color ink and specific-color ink that is used mainly for a foundation (typically, white-colored ink).SOLUTION: First, low resolution is applied to white-plate data subjected to RIP processing (S10). Contraction / expansion processing is applied to the white-plate data subjected to the low resolution (S20). White-plate graphic contraction processing for contracting a white-plate graphic is performed while referring to data obtained through the contraction / expansion processing (S30). High resolution is applied to the white-plate data subjected to the white-plate graphic contraction processing (S40). Graphic correction processing for processing a white-plate graphic included in the white-plate data subjected to the high resolution so that a printing quality can be suppressed from deteriorating (S50). Finally, print data are outputted to a printing device (S60).SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a method for processing printing data (printing data processing method), and more particularly, to a method for processing data of a specific color after RIP processing in a printing system that performs printing using inks of a specific color (typically, white ink) mainly used for a base in addition to process color inks.

Background Art

[0002] In recent years, the spread of inkjet printing devices has been remarkable. In the printing unit of an inkjet printing device, typically, for each of four colors called process colors (C color: cyan, M color: magenta, Y color: yellow, and K color: black), a print head having a large number of nozzles for ejecting ink is provided. Printing is performed by ejecting ink from these numerous nozzles onto a printing medium such as printing paper by heat or pressure. Printing by an inkjet printing device differs from plate printing such as offset printing in that there is no need for a process of producing a printing plate or a process of attaching a printing plate to the printing device. Therefore, printing can be performed in a short time after receiving an order.

[0003] In recent years, inkjet printing equipment for label printing and flexible packaging printing has also been developed. For label printing and flexible packaging printing, transparent substrates such as vinyl and cellophane are often used as printing media. For example, "printing is performed on a transparent substrate, and the printed transparent substrate is then attached to the side of a cylindrical can" (see Figure 38). In such cases, the color of the can itself appears on the surface in areas where ink was not applied during printing. When printing on a transparent substrate in this way, if the printing is done in the same way as when printing on white printing paper, the desired color will not be reproduced. This is because the data values ​​(density) of each color (C, M, Y, and K) are adjusted so that the desired color is reproduced when printing on white printing paper. Therefore, when printing on a transparent substrate, the conventional method has been to "pre-apply white ink to an area that is roughly the same shape as the image or text to be printed, and then apply process color ink on top of that (or apply process color ink first, and then apply white ink on top of that)." Therefore, inkjet printers for label printing and inkjet printers for flexible packaging printing are equipped with a print head that ejects white ink, in addition to print heads that eject process color inks (print heads for C, M, Y, and K).

[0004] Incidentally, in offset printing, when a white plate is used in addition to the four color plates for process colors (C, M, Y, and K), white streaks may appear around the image (here, "image" includes the concept of shapes representing characters) due to misregistration between the white plate and the color plates caused by the expansion and contraction of the printing medium. Similarly, when printing is performed using an inkjet printer with white ink in addition to process color inks, white streaks may appear around the image, similar to offset printing, due to misalignment between the ejection positions of the process color inks and the white inks.

[0005] In the following, the term "misalignment" will also refer to the "misalignment" that causes the white streaks described above when printing with an inkjet printer. Thus, in this specification, for the sake of clarity, the term "plate" will be used when describing an inkjet printer that performs plateless printing. For example, process color data will be called "color plate data," white data will be called "white plate data," a figure corresponding to the area to which the desired color ink is applied based on the color plate data will be called a "color plate figure," and a figure corresponding to the area to which white ink is applied based on the white plate data will be called a "white plate figure."

[0006] To prevent white streaks from appearing around a figure due to misregistration, it has been conventional practice to make the white figure smaller than the color figure by thinning it. Incidentally, the process of thinning a figure overall by changing the data values ​​(pixel values) of pixels located at the periphery of the figure is called "shrinkage" in the field of image processing. Therefore, in this specification, the series of processes for thinning a white figure will be called "white figure shrinkage." Shrinkage of a white figure is performed as follows: With respect to the white data, pixels with data values ​​other than 0 are designated as focus pixels, and if there is even one pixel with a data value of 0 around the focus pixel, the data value of the focus pixel is rewritten from its original value to 0. In this way, the white figure is shrunk overall.

[0007] The white ink graphic reduction process will be further explained with reference to Figure 39. Let's assume that if the white ink graphic reduction process is not performed, white streaks will appear, for example, as shown in the area labeled 91 in section A of Figure 39. In this case, if the white ink graphic is thinned by 1 pixel width using the white ink graphic reduction process, the white streaks will become thinner, for example, as shown in the area labeled 92 in section B of Figure 39. Furthermore, in this example, by further increasing the amount by which the white ink graphic is thinned by the white ink graphic reduction process (hereinafter referred to as the "thinning width"), a printed image without white streaks (for example, a printed image as shown in section C of Figure 39) can be obtained.

[0008] As described above, white plate graphic shrinkage processing suppresses the appearance of white streaks around graphics caused by misregistration. However, if the data to be processed consists of complex graphics, the time required for white plate graphic shrinkage processing increases, reducing the overall processing efficiency of printing. Therefore, Japanese Patent Publication No. 2018-012262 discloses a technique for performing white plate graphic shrinkage processing at high speed by performing the processing on raster data instead of vector data. In addition, although not a technique related to white plate graphic shrinkage processing, Japanese Patent Publication No. 2013-071426 discloses a technique for reducing processing time in image processing that generates data for coating processes such as overcoat processing by reducing the resolution of the input image data. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2018-012262 [Patent Document 2] Japanese Patent Publication No. 2013-071426 [Overview of the project] [Problems that the invention aims to solve]

[0010] Generally, flexible packaging printing uses larger substrate sizes and resolutions compared to label printing. Consequently, the number of pixels processed by the white ink graphic shrinkage process is greater for flexible packaging printing than for label printing. Furthermore, comparing label printing using UV ink (ultraviolet-curing ink) with flexible packaging printing using water-based ink, the time required for ink fixing (curing for UV ink, drying for water-based ink) is longer for flexible packaging printing than for label printing. Therefore, the distance between the print head for process color and the print head for white ink is longer for flexible packaging printing than for label printing. As a result, the misalignment (misregistration) between the print position of process color ink and the print position of white ink is greater for flexible packaging printing than for label printing. Therefore, in the white ink graphic shrinkage process, a larger shrinkage width is required for flexible packaging printing compared to label printing. In summary, the longer time required for the white ink graphic shrinkage process in flexible packaging printing reduces the overall efficiency of the printing process. Similar concerns may arise in label printing in the future, for example, when the resolution increases.

[0011] Furthermore, regarding the white ink graphic shrinkage process, it is possible to exclude fine lines below a certain width from shrinkage in order to prevent the disappearance of fine lines necessary for the printed image due to the shrinkage process. For example, if the exclusion width is set to 0.4 mm and the white ink graphic shrinkage process is executed, fine lines with a width of 0.4 mm or less will not disappear due to the white ink graphic shrinkage process. To achieve this, a process of shrinking and expanding the white ink data (hereinafter referred to as "shrinkage / expansion process") is performed before the white ink graphic shrinkage process is executed, but the time required for this shrinkage / expansion process is significantly longer. According to one experiment, the time from the start of the RIP process to the end of the white ink graphic shrinkage process was 29 seconds when the exclusion width was set to 0 mm and the white ink graphic shrinkage process was executed (in this case, no shrinkage / expansion process is performed), while it was 10 minutes and 19 seconds when the exclusion width was set to 0.4 mm and the white ink graphic shrinkage process was executed. Thus, the significant time required for the shrinkage / expansion process also reduces the overall efficiency of the printing process.

[0012] Considering the above circumstances, it is necessary to shorten the time required for white ink graphic shrinkage processing and shrinkage / expansion processing, but it is undesirable for the print quality to deteriorate as a result of shortening these processing times.

[0013] Therefore, the present invention relates to printing using process color inks and specific color inks mainly used as undercoats, and aims to shorten the time required to generate the final print data (print data provided to the printing device) without degrading print quality. [Means for solving the problem]

[0014] The first invention is a method for processing print data which is raster data comprising process color data including a main figure corresponding to an area to be coated with process color ink and first specific color data including a first specific color figure corresponding to an area to be coated with ink of a specific color other than process color, A low-resolution step of generating second specific color data including a second specific color figure corresponding to the first specific color figure by reducing the resolution of the first specific color data, A specific color figure shrinking step that generates third specific color data including a third specific color figure by applying a shrinking process to the second specific color figure, A high-resolution step of generating a fourth specific color data including a fourth specific color figure corresponding to the third specific color figure by increasing the resolution of the third specific color data, A figure modification step to generate fifth specific color data including a fifth specific color figure by replacing the fourth specific color figure with the first specific color figure in at least a portion of the overall area corresponding to the fourth specific color data; It is characterized by including.

[0015] The second invention is, in the first invention, The figure modification step is characterized in that a masking process using the first specific color figure is applied to the fourth specific color figure so that the portion of the fourth specific color figure that is outside the outline of the first specific color figure is deleted, thereby generating the fifth specific color data including the fifth specific color figure.

[0016] The third invention is, in the first invention, The figure modification step is characterized in that, in the region where the fourth specific color figure and the main figure do not overlap, the pixel values ​​in the fourth specific color data are replaced with the pixel values ​​in the first specific color data, thereby generating the fifth specific color data including the fifth specific color figure.

[0017] The fourth invention is, in the first invention, The figure modification step is characterized in that a masking process is applied to the fourth specific color figure using the first specific color figure so that the portion of the fourth specific color figure corresponding to the area outside the outline of the first specific color figure is deleted, and the pixel values ​​in the fourth specific color data are replaced with the pixel values ​​in the first specific color data in the area where the fourth specific color figure and the main figure do not overlap, thereby generating the fifth specific color data including the fifth specific color figure.

[0018] The fifth invention is, in the first invention, The graphic modification step is characterized in that the fifth specific color data, which includes the fifth specific color graphic, is generated by replacing the pixel values ​​of pixels in the fourth specific color data that have pixel values ​​other than 0 with the pixel values ​​in the first specific color data.

[0019] The sixth invention relates to any of the first to fifth inventions, The printing data processing method includes a shrinking and expanding step of generating shrinkage determination data by shrinking a second specific color figure by a first width, which is a threshold value for distinguishing whether or not the second specific color figure is to be the target of shrinkage processing in the specific color figure shrinking step, by the first width and then expanding it by the first width after the low-resolution conversion step and before the specific color figure shrinking step. In the specific color figure shrinking step, a second specific color figure in which the corresponding figure is not included in the shrinkage determination data is excluded from the target of shrinkage processing.

[0020] A seventh invention is any one of the first to fifth inventions, Taking M and N as natural numbers, in the low-resolution conversion step, the resolution of the first specific color data is made 1 / M times in the horizontal axis direction and 1 / N times in the vertical axis direction by obtaining the average value of pixel values for every (M×N) pixels with respect to the first specific color data, and the second specific color data is generated.

[0021] An eighth invention is any one of the first to fifth inventions, In the high-resolution conversion step, the fourth specific color data is generated by increasing the resolution of the third specific color data using the nearest neighbor interpolation method.

[0022] A ninth invention is any one of the first to fifth inventions, The printing data processing method further includes a printing data output step of outputting the process color data and the fifth specific color data to a printing apparatus.

[0023] A tenth invention is any one of the first to fifth inventions, The specific color is white.

[0024] An eleventh invention is any one of the first to fifth inventions, The specific color figure shrinking step is A step to calculate a contraction candidate region, which is a candidate region for contracting the second specific color figure included in the second specific color data, A colored area calculation step in which the colored area, which is the area to be coated with process color ink, is determined based on the process color data, A painting target area calculation step in which a set of pixels included in at least one of the colored area and the area to be coated with the specific color ink based on the second specific color data is determined as the painting target area, A shrinkage permission area calculation step is to calculate a shrinkage permission area, which is an area in which the shrinkage of the second specific color figure included in the second specific color data is permitted by applying a shrinkage process to the area to be painted, A step to identify a region to be reduced, in which the region of pixels included in all of the candidate region to be reduced, the colored region, and the permitted region to be reduced is defined as the region to be reduced, A specific color data update step that generates the third specific color data by rewriting the pixel values ​​of pixels included in the shrinkage target region of the second specific color data so that the amount of ink of the specific color applied to those pixels is reduced. It is characterized by including.

[0025] The twelfth invention is a method for processing print data which is raster data comprising image data including a main figure corresponding to an area to be coated with an image-forming ink and first base data including a first base map shape corresponding to an area to be coated with a base coat, A low-resolution step of generating second background data including a second background map shape corresponding to the first background map shape by reducing the resolution of the aforementioned background data, A specific color shape shrinking step that generates a third background data including a third background map shape by applying a shrinking process to the second background map shape, A high-resolution step of generating a fourth background data including a fourth background map shape corresponding to the third background map shape by increasing the resolution of the third background data, A graphic modification step to generate a fifth background data including a fifth background shape by replacing the fourth background map shape with the first background map shape in at least a portion of the overall area corresponding to the fourth background data; It is characterized by including.

[0026] The 13th invention is a print data processing device that processes print data which is raster data consisting of process color data including a main figure corresponding to an area to be coated with process color ink and first specific color data including a first specific color figure corresponding to an area to be coated with ink of a specific color other than process color, A low-resolution means for generating second specific color data including a second specific color figure corresponding to the first specific color figure by reducing the resolution of the first specific color data, A specific color figure shrinking means that generates a third specific color data including a third specific color figure by applying a shrinking process to the second specific color figure, A high-resolution means for generating a fourth specific color data including a fourth specific color figure corresponding to the third specific color figure by increasing the resolution of the third specific color data, A graphic modification means for generating fifth specific color data including a fifth specific color figure by replacing the fourth specific color figure with the first specific color figure in at least a portion of the overall area corresponding to the fourth specific color data, and It is characterized by having the following features.

[0027] The fourteenth invention is a printing system comprising a printing data processing device that generates second printing data by processing first printing data which is raster data consisting of process color data including a main figure corresponding to an area to be coated with process color ink and first specific color data including a first specific color figure corresponding to an area to be coated with ink of a specific color other than process color, and a printing device that prints on a printing medium based on the second printing data, The print data processing device is A low-resolution means for generating second specific color data including a second specific color figure corresponding to the first specific color figure by reducing the resolution of the first specific color data, A specific color figure shrinking means that generates a third specific color data including a third specific color figure by applying a shrinking process to the second specific color figure, A high-resolution means for generating a fourth specific color data including a fourth specific color figure corresponding to the third specific color figure by increasing the resolution of the third specific color data, A graphic modification means for generating fifth specific color data including a fifth specific color figure by replacing the fourth specific color figure in at least a portion of the overall area corresponding to the fourth specific color data with the first specific color figure, A print data output means that outputs the process color data and the fifth specific color data as the second print data to the printing device. Equipped with, The aforementioned printing apparatus, A transport mechanism for transporting the aforementioned printing medium, A first printing unit that ejects process color ink onto the printing medium being transported by the transport mechanism based on the process color data, A first fixing unit that fixes the ink ejected from the first printing unit onto the printing medium, A second printing unit that ejects ink of the specified color onto the printing medium being transported by the transport mechanism based on the fifth specified color data, The device is characterized by comprising a second fixing unit for fixing the ink ejected from the second printing unit onto the printing medium.

[0028] The 15th invention is a print data processing program that processes print data which is raster data consisting of process color data including a main figure corresponding to an area to be coated with process color ink and first specific color data including a first specific color figure corresponding to an area to be coated with ink of a specific color other than process color, On the computer, A low-resolution step of generating second specific color data including a second specific color figure corresponding to the first specific color figure by reducing the resolution of the first specific color data, A specific color figure shrinking step that generates third specific color data including a third specific color figure by applying a shrinking process to the second specific color figure, A high-resolution step of generating a fourth specific color data including a fourth specific color figure corresponding to the third specific color figure by increasing the resolution of the third specific color data, A figure modification step to generate fifth specific color data including a fifth specific color figure by replacing the fourth specific color figure with the first specific color figure in at least a portion of the overall area corresponding to the fourth specific color data; Make it run. [Effects of the Invention]

[0029] According to the first invention described above, a shrinkage process (e.g., white plate shape shrinkage process) is performed on the low-resolution data of the specific color (second specific color data) to make the specific color shape smaller than the main shape (process color shape) in order to suppress the appearance of streaks of a specific color (e.g., white) around the shape due to misregistration. This reduces the number of pixels processed in the shrinkage process to make the specific color shape smaller than in the conventional method. Consequently, the time required for the shrinkage process to make the specific color shape smaller is shortened. Here, a resolution conversion process (low-resolution and high-resolution) is added compared to the conventional method, but by appropriately selecting the algorithm used for the resolution conversion process, the overall processing time involved in generating the final print data can be shortened. Furthermore, a shape correction process is applied to the high-resolution data of the specific color (fourth specific color data) to suppress the deterioration of print quality caused by the resolution conversion. As a result, with respect to printing using process color ink and specific color ink, a reduction in the time required to generate the final print data (print data provided to the printing device) is achieved without degrading print quality.

[0030] According to the second invention described above, the width of the figure, which has become thicker than it should be due to the resolution conversion, is corrected to its original width by the processing of the figure correction step. This prevents the width of the figure from becoming inappropriately thicker due to the resolution conversion.

[0031] According to the third invention described above, the figure correction step replaces figures whose smoothness of contours has been compromised due to resolution conversion with the original figures. This prevents printed images based on figures of a specific color from becoming blurred due to resolution conversion.

[0032] According to the fourth invention described above, the shape correction step corrects the width of a shape that has become thicker than its original width due to resolution conversion back to its original width. This prevents the shape from becoming inappropriately thicker due to resolution conversion. In addition, the shape correction step replaces a shape whose smoothness of outline has been lost due to resolution conversion with its original shape. This prevents a printed image based on a shape of a specific color from becoming blurred due to resolution conversion.

[0033] According to the fifth invention described above, the same effects as those of the fourth invention described above can be obtained.

[0034] According to the sixth invention described above, it becomes possible to exclude shapes with a width of less than a certain width (such as thin lines) from the shrinkage process in the specific color shape shrinkage step. This prevents shapes necessary for the printed image from disappearing due to the shrinkage process.

[0035] According to the seventh invention described above, the process of reducing the resolution of the first specific color data is performed in a relatively short time.

[0036] According to the eighth invention described above, the process of increasing the resolution of the third specific color data is performed in a relatively short time.

[0037] According to the ninth invention described above, the same effects as those of the first invention described above can be obtained.

[0038] According to the tenth invention described above, with respect to printing using process color ink and white ink, it is possible to shorten the time required to generate the final print data (print data to be provided to the printing device) without degrading the print quality.

[0039] According to the 11th invention described above, instead of applying a simple shrinkage process to a figure of a specific color, only pixels within the shrinkage candidate region, which are candidates for shrinkage of the figure of a specific color, that are located in the region where the process color figure exists are designated as targets for shrinkage. In other words, pixels that are not coated with process color ink on top of the ink of a specific color are not targeted for shrinkage. As a result, it is prevented that part or all of the figure of a specific color (for example, letters of a specific color or thin lines of a specific color) will disappear or become thinner. In addition, it is prevented that the letter portion of cutout letters formed with data of a specific color will become thicker. Thus, the shrinkage process in the specific color figure shrinkage step is performed while ensuring sufficient print quality.

[0040] According to the 12th invention described above, in cases where an area to which a primer has been applied is treated as part of a printed image, it is possible to shorten the time required to generate the final print data (print data to be provided to the printing device) without degrading the print quality.

[0041] According to the 13th invention described above, the same effects as those of the first invention described above can be obtained.

[0042] According to the 14th invention described above, the same effects as those of the first invention described above can be obtained.

[0043] According to the 15th invention described above, the same effects as those of the first invention described above can be obtained. [Brief explanation of the drawing]

[0044] [Figure 1] This is an overall configuration diagram of a printing system according to one embodiment of the present invention. [Figure 2] This is a block diagram showing an example of the functional configuration of an inkjet printing apparatus in the above embodiment. [Figure 3] This is a block diagram showing another example of the functional configuration of an inkjet printing apparatus in the above embodiment. [Figure 4] This is a hardware configuration diagram of the print data generation device in the above embodiment. [Figure 5] This block diagram shows the functional configuration of the print data generation device in the above embodiment. [Figure 6] This flowchart shows the overall outline of the print data processing procedure in the above embodiment. [Figure 7] This figure illustrates the shrinkage and expansion process in the above embodiment. [Figure 8] This figure illustrates the shrinkage and expansion process in the above embodiment. [Figure 9] This figure illustrates the shrinkage and expansion process in the above embodiment. [Figure 10] This figure illustrates the shrinkage and expansion process in the above embodiment. [Figure 11] This figure shows an example of white text. [Figure 12] This diagram illustrates how some of the white text disappears due to the shrinkage process. [Figure 13] This figure shows an example of white text. [Figure 14] This diagram illustrates how white text becomes bolder due to the shrinking process. [Figure 15] This diagram illustrates the use of white-plate and K-plate graphics. [Figure 16] This diagram illustrates the use of white-plate and K-plate graphics. [Figure 17] This diagram illustrates the use of white-plate and K-plate graphics. [Figure 18]This diagram illustrates the use of white-plate and K-plate graphics. [Figure 19] This diagram illustrates the use of white-plate and K-plate graphics. [Figure 20] This flowchart shows the procedure for the white ink graphic shrinkage process in the above embodiment. [Figure 21] This figure illustrates the shrinkage process using a 3x3 shrinkage filter in the above embodiment. [Figure 22] This diagram illustrates the processing of ordinary shapes in the above embodiment. [Figure 23] This diagram illustrates the processing of ordinary shapes in the above embodiment. [Figure 24] This diagram illustrates the processing of ordinary shapes in the above embodiment. [Figure 25] This figure illustrates the processing of white characters in the above embodiment. [Figure 26] This is a diagram illustrating the processing of white text in the above embodiment. [Figure 27] This diagram illustrates the process in the above embodiment where a normal graphic and white text are mixed. [Figure 28] This diagram illustrates the process in the above embodiment where a normal graphic and white text are mixed. [Figure 29] This diagram illustrates the process in the above embodiment where a normal graphic and white text are mixed. [Figure 30] This diagram illustrates the process in the above embodiment where a normal graphic and white text are mixed. [Figure 31] This figure illustrates the processing of data having overlapping portions in the above embodiment. [Figure 32] This figure illustrates the graphic modification process in the above embodiment. [Figure 33]This figure illustrates the graphic modification process in the above embodiment. [Figure 34] This figure illustrates the graphic modification process in the above embodiment. [Figure 35] This figure illustrates the graphic modification process in the above embodiment. [Figure 36] This figure illustrates the graphic modification process in the above embodiment. [Figure 37] This figure illustrates the graphic modification process in the above embodiment. [Figure 38] This is a diagram illustrating printing on a transparent substrate. [Figure 39] This diagram illustrates the process of shrinking white ink graphics. [Modes for carrying out the invention]

[0045] One embodiment of the present invention will be described below with reference to the attached drawings. In the printing system according to the following embodiment, plateless printing is performed, but as mentioned above, the term "plate" will be used for the sake of explanation. In addition, while the resolution of printing is generally expressed by the vertical resolution and the horizontal resolution, in the following explanation, for the sake of convenience, it will be assumed that the vertical resolution and the horizontal resolution are the same, and a single resolution will be used to represent the resolution in both the vertical and horizontal directions. For example, "the resolution is 1200 dpi" means that the resolution in both the vertical and horizontal directions is 1200 dpi.

[0046] <1. Overall configuration of the printing system> Figure 1 is an overall configuration diagram of a printing system according to one embodiment of the present invention. This printing system consists of an inkjet printing device 10 and a print data generation device 30. The inkjet printing device 10 consists of a printing press body 100 and a print control device 200 that controls the operation of the printing press body 100. The inkjet printing device 10 and the print data generation device 30 are connected to each other by a communication line 4. The print data generation device 30 generates bitmap format print data by applying RIP processing to input data such as PDF files. The print data generation device 30 also applies data processing such as white plate graphic shrinkage processing to the bitmap format print data. Hereinafter, the series of processes applied to the bitmap format print data obtained by RIP processing will be referred to as "print data processing". Furthermore, when distinguishing between print data before and after the execution of print data processing, the print data before the execution of print data processing will be referred to as "first print data", and the print data after the execution of print data processing will be referred to as "second print data". The second print data is transmitted from the print data generation device 30 to the print control device 200 via the communication line 4. Then, the print control device 200 issues a print instruction to the printing press body 100, and printing is performed based on the second print data. In this embodiment, the printing press body 100 performs printing by ejecting ink onto a printing medium such as a transparent substrate, such as a flexible packaging film, without using a printing plate. In this embodiment, the print data processing device is realized by the print data generation device 30.

[0047] <2. Configuration of an inkjet printing device> Figure 2 is a block diagram showing an example of the functional configuration of the inkjet printing apparatus 10 in this embodiment. As described above, the inkjet printing apparatus 10 consists of a printing machine body 100 and a printing control device 200.

[0048] The printing press body 100 includes a transport mechanism 110 for transporting a printing medium 5 such as a flexible packaging film, a primer application unit 120 for applying a primer (coating liquid) to the printing medium 5 to form a base layer, a color printing unit 130 for printing by ejecting process color ink onto the printing medium 5 on which the base layer has been formed, a pre-drying unit 140 for pre-drying the printed surface of the printing medium 5 after color printing, a white printing unit 150 for printing by ejecting white ink onto the printing medium 5 after color printing, an upper drying unit 160 for drying the printed surface of the printing medium 5 after white printing, and a main drying unit 170 for drying both the printed surface and its back surface of the printing medium 5 printed by the color printing unit 130 and the white printing unit 150. In this example, the first printing section is realized by the color printing section 130, the first fixing section is realized by the pre-drying section 140, the second printing section is realized by the white printing section 150, and the second fixing section is realized by the upper drying section 160. Some inkjet printing devices are equipped with an imaging unit (e.g., a CIS sensor) that captures an image of the printed image (printed medium 5 after printing) to check whether the printing has been performed correctly.

[0049] The color printing section 130 is composed of four print heads that eject C, M, Y, and K inks, respectively. The white printing section 150 is composed of a print head that ejects white ink. Each print head is composed of multiple head modules arranged, for example, in a staggered pattern. Each head module contains numerous nozzles that eject ink. The process color inks and white ink are water-based inks. As can be seen from the above configuration, in this embodiment, printing is performed using white ink in addition to process color inks. Therefore, the print data is composed of four color plate data (C plate data, M plate data, Y plate data, and K plate data) and white plate data.

[0050] The print control device 200 comprises a primer control unit 210, a print control unit 220, a drying control unit 230, and a transport control unit 240. The primer control unit 210 controls the application of primer to the print medium 5 by the primer application unit 120. The print control unit 220 controls the ejection of ink from each nozzle contained in each print head that constitutes the color print unit 130 and the white print unit 150. The drying control unit 230 controls the temperature when the pre-drying unit 140, the upper drying unit 160, and the main drying unit 170 dry the print medium 5. The transport control unit 240 controls the speed at which the transport mechanism 110 transports the print medium 5 (transport speed).

[0051] Figure 2 shows an example configuration of an inkjet printing apparatus 10 that uses water-based ink for printing. However, the present invention can also be applied to inkjet printing apparatuses that use UV ink (ultraviolet-curable ink). Therefore, with reference to Figure 3, an example of the functional configuration of an inkjet printing apparatus that uses UV ink will be described. This inkjet printing apparatus also consists of a printing press body 100 and a printing control device 200. The printing press body 100 includes a transport mechanism 110 for transporting the printing medium 5, a white printing unit 150 that performs printing by ejecting white ink onto the printing medium 5, a white curing unit 161 that cures the white ink ejected onto the printing medium 5, a color printing unit 130 that performs printing by ejecting process color ink onto the printing medium 5 after white printing, and a color curing unit 141 that cures the process color ink ejected onto the printing medium 5. The white curing unit 161 and the color curing unit 141 cure the ink by irradiating it with UV light (ultraviolet light). The print control device 200 comprises a print control unit 220, a curing control unit 231, and a transport control unit 240. The print control unit 220 controls the ejection of ink from each nozzle contained in each print head that constitutes the white printing unit 150 and the color printing unit 130. The curing control unit 231 controls the intensity of UV light when the white curing unit 161 and the color curing unit 141 cure the ink. The transport control unit 240 controls the speed at which the transport mechanism 110 transports the printing medium 5 (transport speed). In this example, the first printing unit is realized by the color printing unit 130, the first fixing unit is realized by the color curing unit 141, the second printing unit is realized by the white printing unit 150, and the second fixing unit is realized by the white curing unit 161.

[0052] In this embodiment, white ink corresponds to a specific color of ink.

[0053] <3. Print Data Generation Device> <3.1 Hardware Configuration> Figure 4 is a hardware configuration diagram of the print data generation device 30 in this embodiment. The print data generation device 30 includes a main unit 310, an auxiliary storage device 321, an optical disc drive 322, a display unit 323, a keyboard 324, and a mouse 325. The main unit 310 includes a CPU 311, a memory 312, a first disk interface unit 313, a second disk interface unit 314, a display control unit 315, an input interface unit 316, and a network interface unit 317. The CPU 311, memory 312, first disk interface unit 313, second disk interface unit 314, display control unit 315, input interface unit 316, and network interface unit 317 are connected to each other via a system bus. The auxiliary storage device 321 is connected to the first disk interface unit 313. The auxiliary storage device 321 is a magnetic disk drive or the like. The optical disc drive 322 is connected to the second disk interface unit 314. An optical disc 7, such as a CD-ROM or DVD-ROM, is inserted into the optical disc drive 322. A display unit (display device) 323 is connected to the display control unit 315. The display unit 323 is a liquid crystal display or the like. The display unit 323 is used to display information desired by the operator. A keyboard 324 and a mouse 325 are connected to the input interface unit 316. The keyboard 324 and mouse 325 are used by the operator to input instructions to this print data generation device 30. The network interface unit 317 is a wired or wireless communication interface circuit and is connected to the communication line 4.

[0054] The auxiliary storage device 321 stores a print data processing program 6 for executing print data processing. The CPU 311 reads the print data processing program 6 stored in the auxiliary storage device 321 into the memory 312 and executes it, thereby realizing various functions related to print data processing. The memory 312 includes RAM and ROM. The memory 312 functions as a work area for the CPU 311 to execute the print data processing program 6 stored in the auxiliary storage device 321. The print data processing program 6 is provided, for example, stored in the above-mentioned computer-readable recording medium (non-transient recording medium).

[0055] <3.2 Functional Configuration> Figure 5 is a block diagram showing the functional configuration of the print data generation device 30. As shown in Figure 5, the print data generation device 30 includes a RIP processing unit 31, a low-resolution processing unit 32, a shrink / expansion processing unit 33, a white plate graphic shrinkage processing unit 34, a high-resolution processing unit 35, a graphic correction unit 36, and a print data output unit 37. The low-resolution processing unit 32, the shrink / expansion processing unit 33, the white plate graphic shrinkage processing unit 34, the high-resolution processing unit 35, and the graphic correction unit 36 ​​are realized when the print data processing program 6 is executed in the print data generation device 30.

[0056] The RIP processing unit 31 generates print data (first print data), which is raster data, by performing RIP processing on the input data DIN, such as a PDF file. The first print data consists of color plate data (C plate data, M plate data, Y plate data, and K plate data) PD and white plate data. Hereinafter, the white plate data generated by the RIP processing will be referred to as the "first white plate data," and the first white plate data will be denoted with the code W1. Furthermore, hereafter, the figure represented by the first white plate data W1 that corresponds to the area to which white ink is to be applied will be referred to as the "first white plate figure."

[0057] The low-resolution unit 32 reduces the resolution of the first white plate data W1 to generate second white plate data W2 which includes a second white plate figure corresponding to the first white plate figure. For example, by applying low-resolution processing to the first white plate data W1, which has a resolution of 1200 dpi, the low-resolution unit 32 generates second white plate data W2 with a resolution of 200 dpi.

[0058] The shrink / expansion processing unit 33 applies shrink / expansion processing to the second white plate data W2 in order to determine whether each second white plate figure contained in the second white plate data W2 is a figure that is not subject to shrinkage in the white plate figure shrinkage processing. This shrink / expansion processing generates shrinkage determination data WD.

[0059] The white plate shape contraction processing unit 34 applies the above-described white plate shape contraction processing to the second white plate shape, which is a white plate shape included in the second white plate data W2, while referring to the contraction determination data WD and the color plate data PD. As a result, the third white plate data W3 is generated, which includes the third white plate shape, which is the white plate shape after contraction. The amount by which the white plate shape is thinned by the white plate shape contraction processing (thinning width) can be set in advance. For the sake of explanation in this embodiment, we will assume that the thinning width is set so that the white plate shape to be contracted in the white plate data after low resolution (i.e., the second white plate data W2) is thinned by 1 pixel. The specific color shape contraction means is realized by this white plate shape contraction processing unit 34.

[0060] The high-resolution unit 35 increases the resolution of the third white plate data W3 generated by the white plate figure reduction process, thereby generating a fourth white plate data W4 that includes a fourth white plate figure corresponding to the third white plate figure. For example, by applying high-resolution enhancement to the third white plate data W3, which has a resolution of 200 dpi, the high-resolution unit 35 generates a fourth white plate data W4 with a resolution of 1200 dpi.

[0061] The graphic correction unit 36 ​​performs a graphic correction process on the white plate figures (fourth white plate figures) included in the high-resolution white plate data (fourth white plate data W4) in order to suppress the deterioration of print quality caused by the white plate figure shrinkage process performed using the low-resolution white plate data (second white plate data W2). Through this graphic correction process, the fourth white plate figures in at least a portion of the overall area corresponding to the fourth white plate data W4 are replaced with the first white plate figures (white plate figures included in the first white plate data W1). As a result, the fifth white plate data W5, which includes the fifth white plate figure, is generated.

[0062] The print data output unit 37 outputs the color plate data PD generated by the RIP processing unit 31 and the fifth white plate data W5 generated by the graphic correction unit 36 ​​as second print data to the inkjet printing device 10.

[0063] <4. Overall outline of the print data processing procedure> Figure 6 is a flowchart illustrating the overall procedure for print data processing in this embodiment. It is assumed that, prior to the execution of this print data processing, RIP processing is performed on the submitted data DIN to generate print data (first print data), which is raster data. As described above, this print data consists of color plate data PD and first white plate data W1.

[0064] After the start of print data processing, the first white plate data W1 is first subjected to a resolution reduction by the resolution reduction unit 32 (step S10). As described above, for example, by applying a resolution reduction to the first white plate data W1, which has a resolution of 1200 dpi, a second white plate data W2 with a resolution of 200 dpi is generated. The algorithm for resolution reduction is not particularly limited, but in this embodiment, an algorithm using averaging is employed. Specifically, with M and N as natural numbers, the average value of the data value (pixel value) is calculated for every (M × N) pixels of the first white plate data W1, thereby generating a second white plate data W2 in which the resolution of the first white plate data W1 is multiplied by 1 / M in the horizontal direction and by 1 / N in the vertical direction. In the above example, the second white plate data W2 is generated by reducing the resolution of the first white plate data W1 by 1 / 6 in the horizontal direction and 1 / 6 in the vertical direction.

[0065] Next, the shrink / expansion processing unit 33 performs a shrink / expansion process on the second white plate data W2 (step S20). This shrink / expansion process will be explained with reference to Figures 7 to 10. Figures 7 to 10 show a portion of the entire image to be printed, and in Figures 7 to 10, one section enclosed by a dotted line represents one pixel. If a 4-pixel wide white plate figure exists in the second white plate data W2 as shown in Figure 7, the white plate figure disappears as shown in Figure 8 by performing a shrink process using a known method with a 5x5 shrink filter. In this case, even if the data after the shrink process is expanded, the 4-pixel wide white plate figure will not appear. On the other hand, if a 5-pixel wide white plate figure exists in the second white plate data W2 as shown in Figure 9, the 5-pixel wide white plate figure changes into a 1-pixel wide white plate figure as shown in Figure 10 by performing a shrink process using a known method with a 5x5 shrink filter. At this point, when the data after the shrinking process is expanded, a white platen shape with a width of 5 pixels, as shown in Figure 9, appears. As can be seen from the above, the shrinking and expanding process can eliminate shapes that are not subject to shrinking in the white platen shape shrinking process. Therefore, by excluding shapes that are not included in the shrinking determination data WD generated in step S20 from shrinking in the white platen shape shrinking process, it is possible to prevent thin lines of a certain width or less from disappearing due to the shrinking process. In the above example, 4 pixels at 200 dpi corresponds to the first width (a threshold that distinguishes whether or not the second white platen shape is subject to shrinking in step S30 described later).

[0066] Next, the white plate shape shrinkage processing unit 34 applies white plate shape shrinkage processing to the second white plate shape included in the second white plate data W2 (step S30). This generates the third white plate data W3, which includes the third white plate shape. When executing the white plate shape shrinkage processing, the shrinkage determination data WD generated in step S20 is referenced. Second specific color shapes whose corresponding shapes are not included in the shrinkage determination data WD are excluded from the shrinkage processing. As a result, thin lines of a certain width or less are prevented from disappearing due to the shrinkage processing. A detailed explanation of the white plate shape shrinkage processing performed in step S30 will be given later.

[0067] Next, the resolution enhancement unit 35 enhances the resolution of the third white plate data W3 (step S40). As described above, for example, by enhancing the resolution of the third white plate data W3, which has a resolution of 200 dpi, a fourth white plate data W4 with a resolution of 1200 dpi is generated. By the way, interpolation is necessary when enhancing the resolution. As interpolation algorithms, for example, nearest neighbor interpolation and linear interpolation are known. The interpolation algorithm used in the process of step S40 is not particularly limited, but from the viewpoint of shortening processing time, it is preferable to use nearest neighbor interpolation rather than linear interpolation. This is because nearest neighbor interpolation requires less computation than linear interpolation.

[0068] Next, the graphic correction unit 36 ​​performs a graphic correction process (step S50) on the white plate data after high resolution (fourth white plate data W4) to process the white plate figures (fourth white plate figures) included in the white plate data after high resolution (fourth white plate data W4) in order to suppress the decrease in print quality caused by the white plate figure shrinkage process performed using the white plate data after low resolution (second white plate data W2). This generates the fifth white plate data W5, which includes the fifth white plate figure. A detailed explanation of the graphic correction process performed in step S50 will be given later.

[0069] Finally, the print data output unit 37 outputs the color plate data PD and the fifth white plate data W5 generated in step S50 (step S60). These color plate data PD and fifth white plate data W5 are provided to the print control device 200 in the inkjet printing apparatus 10 as print data (second print data).

[0070] In this embodiment, step S10 is performed to reduce resolution, step S20 is performed to shrink / expand, step S30 is performed to shrink specific color figures, step S40 is performed to increase resolution, step S50 is performed to correct figures, and step S60 is performed to output print data.

[0071] In this embodiment, the series of processes shown in Figure 6 are performed by the print data generation device 30, but these processes may also be performed by the print control device 200. However, in this case, the process in step S60 is unnecessary.

[0072] <5. White-ink graphic contraction processing> The following describes the white ink graphic shrinkage process (a series of processes to make the white ink graphic thinner) in this embodiment.

[0073] <5.1 Overview> In this embodiment, the white plate shape shrinkage process is performed on the data after RIP processing (first white plate data W1), that is, on the raster data. In this regard, if a simple shrinkage process is applied to a white plate shape after RIP processing (for example, if the outline of the white plate shape is shrunk by 1 pixel without considering the relationship between the white plate shape and the color plate shape), some or all of the characters and thin lines corresponding to the white plate shape may disappear or become thinner. For example, if there are white characters as shown in Figure 11 (the white part represents the area where white ink should be applied), the shape of the white characters will become the shape shown in Figure 12 after the shrinkage process. Also, there are cases where so-called "cut-out characters" are constructed using the white plate, but if a simple shrinkage process is applied to such a white plate shape, the character part will become thicker. For example, if there are white cut-out characters as shown in Figure 13 (the white part represents the area where white ink should be applied), the shape of the white cut-out characters will become the shape shown in Figure 14 after the shrinkage process.

[0074] Furthermore, in the following case using white plate figures and K plate figures (figures corresponding to areas where black ink is applied based on K plate data), a simple shrinkage process may lead to a decrease in print quality. Figure 15 is a schematic representation of white plate data, and Figure 16 is a schematic representation of K plate data. Regarding the white plate data, the white areas in Figure 15 are the areas that should be painted with white ink. Regarding the K plate data, in Figure 16, the areas other than the shaded area indicated by reference numeral 66 are the areas that should be painted with black ink. Note that in Figure 16, the area within the thick border indicated by reference numeral 67 corresponds to the white areas in Figure 15 (areas that should be painted with white ink). When the white plate data and K plate data are superimposed, the white plate figure and the K plate figure overlap in the shaded area indicated by reference numeral 69 in Figure 17. The reason for providing this overlapping area between the white plate figure and the K plate figure is to prevent the color of the substrate (or, if the substrate is transparent, the color of the object to which the substrate is attached) from appearing even if misregistration occurs between the white plate and the K plate. In such cases, if a simple shrinkage process is applied to the white plate graphic, the overlapping area between the white plate graphic and the K plate graphic disappears, as shown in Figure 18. As a result, if misregistration occurs between the white plate and the K plate, areas where the color of the substrate appears on the surface will occur, for example, the shaded area indicated by reference numeral 70 in Figure 19.

[0075] As mentioned above, simply applying a shrinking process to the white plate graphics after RIP processing will not yield print results of sufficient quality. Therefore, in this embodiment, the process of thinning the white plate graphics is performed while considering whether or not ink of a color other than white will be applied on top of the white ink. The procedure for the white plate graphics shrinking process in this embodiment will be described below. In the following description, it is assumed that for each plate data, the data value (pixel value) of pixels that are not to be painted with the corresponding color ink is 0, and the data value of pixels that are to be painted with the corresponding color ink is a value corresponding to the gradation (a value other than 0). For example, with respect to white plate data, pixels with a data value other than 0 will be coated with an amount of white ink corresponding to the data value, and pixels with a data value of 0 will not be coated with white ink. Also, for example, with respect to C plate data, pixels with a data value other than 0 will be coated with an amount of cyan ink corresponding to the data value, and pixels with a data value of 0 will not be coated with cyan ink.

[0076] <5.2 Processing Procedure> Figure 20 is a flowchart showing the procedure for white plate graphic reduction processing in this embodiment. In this embodiment, before the white plate graphic reduction processing is started, the input data DIN is subjected to RIP processing to generate the color plate data PD and the first white plate data W1, and the first white plate data W1 is further subjected to low-resolution processing to generate the second white plate data W2.

[0077] After the white plate shape shrinkage process begins, first, candidate areas to be designated as shrinkage target areas (pixels that will not be painted with white ink) within the area forming the white plate shape (second white plate shape) are determined based on the second white plate data W2 (hereinafter referred to as "shrinkage candidate areas") (step S310). In this step S310, the shrinkage candidate areas are determined by a shrinkage process that applies a 3x3 shrinkage filter to each pixel. For example, with respect to the second white plate data W2, assume that the data value (pixel value) of the pixel indicated by reference numeral 51 in Figure 21 (hereinafter referred to as "focus pixel") is not 0. In this case, if the minimum value of the data values ​​of the 9 pixels centered on the focus pixel 51 (pixels within the thick frame indicated by reference numeral 52) is 0 (i.e., if at least one of the 9 pixels has a data value of 0), then the data value of the focus pixel 51 after the shrinkage process will be 0. By performing this process on the entire second white plate data W1, the set of pixels whose data values ​​have been rewritten from non-zero values ​​to 0 becomes the shrinkage candidate areas. In other words, the areas other than the areas after shrinkage due to the shrinkage process (the areas that form the second white plate figure based on the second white plate data W2) become candidate areas for shrinkage.

[0078] Next, based on the color plate data PD, an area representing the logical OR of the color plate shapes (hereinafter referred to as the "colored area" for convenience) is determined (step S320). In step S320, a data value of "0" is assigned to a logical value of "0", and any data value other than "0" is assigned to a logical value of "1". Pixels with a logical value of 1 for at least one color plate are included in the colored area, while pixels with a logical value of 0 for all color plates are not included. In this way, the colored area, which is the area to be coated with ink of a color other than white (process color ink), is defined.

[0079] Next, the region representing the logical OR of the second white plate data W2 and the colored region (hereinafter referred to as the "paint target region") is determined (step S330). In this step S330, the paint target region is defined as the set of pixels included in at least one of the regions to be coated with white ink based on the second white plate data W2 and the colored region. In other words, the paint target region is defined as the set of pixels to be coated with at least one color of ink.

[0080] Next, in step S340, the area within the area to be filled that is permitted to shrink the white-on-white shape (the second white-on-white shape) is determined (hereinafter referred to as the "shrink-permitted area"). In step S340, the shrink-permitted area is determined by a shrinkage process that applies a 3x3 shrinkage filter to each pixel within the area to be filled, in the same manner as in step S310. That is, the area before shrinkage by the shrinkage process (the area to be filled that was determined in step S330), excluding the area after shrinkage by the shrinkage process, is defined as the shrink-permitted area.

[0081] Next, the final area to be shrunk for the white plate figure (the second white plate figure) is determined (step S350). Specifically, the area representing the logical AND of the candidate area to be shrunk determined in step S310, the colored area determined in step S320, and the permitted area to be shrunk determined in step S340 (i.e., the set of pixels included in all of the candidate area to be shrunk, the colored area, and the permitted area to be shrunk) is defined as the final area to be shrunk.

[0082] Finally, the data values ​​of the pixels included in the final shrinkage target area of ​​the second white plate data W2 are rewritten to 0, thereby generating the third white plate data W3 (step S360). This completes the white plate figure shrinkage process.

[0083] In this embodiment, step S310 is the step for calculating candidate shrinkage regions, step S320 is the step for calculating colored regions, step S330 is the step for calculating regions to be painted, step S340 is the step for calculating regions where shrinkage is permitted, step S350 is the step for identifying regions to be shrinkage, and step S360 is the step for updating specific color data.

[0084] The following provides specific examples to explain the processing performed on various white-print figures (the second white-print figures included in the second white-print data W2).

[0085] <5.2.1 Processing of normal shapes> First, let's explain what processing is performed on normal shapes. Here, "normal shapes" refer to shapes where the shape of the color plate shape and the shape of the white plate shape are exactly the same. Such shapes are typically generated when white ink is applied as an undercoat ink during printing on a transparent substrate. Here, we will focus on the case where both the K plate shape and the white plate shape are rectangular shapes indicated by reference numeral 53 in Figure 22. Note that for color plate data other than the K plate data, we will assume that the data value of all pixels is 0.

[0086] In step S310 above, the 3x3 shrink filter described above is applied to each pixel included in the rectangular shape 53. With respect to the second white plate data W2, the data value of the pixels included in the rectangular shape 53 is a value other than 0, and the data value of the pixels not included in the rectangular shape 53 is 0. Therefore, the shrinking process yields the region represented by the rectangular shape 53s (see Figure 22). As described above, the region before shrinking by the shrinking process (here, the region represented by the rectangular shape 53) excluding the region after shrinking by the shrinking process (here, the region represented by the rectangular shape 53s) becomes the candidate region for shrinking, so the shaded region indicated by reference numeral 54 in Figure 23 is defined as the candidate region for shrinking. In step S320 above, based on the K plate data, the region represented by the rectangular shape 53, i.e., the shaded region indicated by reference numeral 55 in Figure 24, is defined as the colored region.

[0087] In step S330, based on the second white plate data W2 and the colored area obtained in step S320, the same area as the colored area (shaded area 55 in Figure 24) is defined as the area to be filled. In step S340, the aforementioned 3x3 shrink filter is applied to each pixel included in the area to be filled. The shrink process using this 3x3 shrink filter yields an area represented by the rectangular shape 53s (see Figure 22). As described above, the area before shrinkage by the shrink process (here, the shaded area 55 in Figure 24) excluding the area after shrinkage by the shrink process (here, the area represented by the rectangular shape 53s in Figure 22) becomes the area permitted to shrink, so the same area as the candidate area to shrink (shaded area 54 in Figure 23) is defined as the area permitted to shrink.

[0088] The final region to be contracted is the region representing the logical AND of the candidate region to be contracted, the colored region, and the region to be contracted. The candidate region to be contracted and the region to be contracted are the shaded region 54 in Figure 23, and the colored region is the shaded region 55 in Figure 24, so the final region to be contracted is the shaded region 54 in Figure 23.

[0089] As described above, among the pixels that form the white plate shape (pixels included in the rectangular shape 53 in Figure 22), the pixels within the shaded area 54 in Figure 23 are not coated with white ink during printing. As a result, even if misregistration occurs between the white plate and the K plate, the desired shrinkage process is applied to the white plate shape, thus suppressing the appearance of white streaks around the black rectangular shape based on the K plate data.

[0090] <5.2.2 Processing of white text> Next, we will explain what processing is performed on white text. Here, we will focus on the white text shown in Figure 11. We will assume that the data value of all pixels is 0 for all color plate data.

[0091] In step S310 above, the aforementioned 3x3 shrink filter is applied to each pixel represented in white in Figure 11. With respect to the second white plate data W2, the data values ​​of the pixels represented in white in Figure 11 are non-zero values, and the data values ​​of the pixels in the shaded areas in Figure 11 are 0. Therefore, the shrink process yields the areas represented in white in Figure 12. As described above, the areas before shrinkage by the shrink process (in this case, the areas represented in white in Figure 11) other than the areas after shrinkage by the shrink process (in this case, the areas represented in white in Figure 12) become candidate shrinkage areas, so the shaded area indicated by reference numeral 56 in Figure 25 is determined to be a candidate shrinkage area. Since the data values ​​of all pixels are 0 for all color plate data, there are no areas (pixels) that are determined to be colored areas in step S320 above.

[0092] In step S330 above, based on the second white plate data W2, the area constituting the white characters shown in Figure 11 is defined as the area to be filled. In step S340, the aforementioned 3x3 shrink filter is applied to each pixel included in the area to be filled. The shrink process using this 3x3 shrink filter yields the area shown in white in Figure 12. As described above, the area before shrinkage by the shrink process (here, the area shown in white in Figure 11) excluding the area after shrinkage by the shrink process (here, the area shown in white in Figure 12) becomes the area permitted to shrink, so the same area as the candidate area for shrinkage (shaded area 56 in Figure 25) is defined as the area permitted to shrink.

[0093] The final area to be contracted is the area representing the logical AND of the contraction candidate area, the colored area, and the contraction permitted area. The contraction candidate area and the contraction permitted area are the shaded area 56 in Figure 25, and there are no areas defined in the colored area, so there is no final area to be contracted.

[0094] Therefore, the white text shown in Figure 11 will not be shrunk. Consequently, the white text will be printed with the desired thickness. Note that, as in this example, if the data value of all pixels for all color plate data is 0, there are no areas (pixels) defined in the colored area, and therefore, regardless of the shrinkage permission area, there is no final shrinkage target area. Consequently, after the completion of step S320, this white plate graphic shrinkage process may be terminated without performing the processes in steps S330 to S360.

[0095] <5.2.3 Processing of text in white outline> Next, we will explain what processing is performed on white text. Here, we will focus on the white text shown in Figure 13. We will assume that for all color data, the data value of all pixels is 0.

[0096] In step S310 above, the aforementioned 3x3 shrink filter is applied to each pixel represented in white in Figure 13. With respect to the second white plate data W2, the data values ​​of the pixels represented in white in Figure 13 are non-zero values, and the data values ​​of the pixels in the shaded areas in Figure 13 are 0. Therefore, the shrink process yields the areas represented in white in Figure 14. As described above, the areas before shrinkage by the shrink process (in this case, the areas represented in white in Figure 13) other than the areas after shrinkage by the shrink process (in this case, the areas represented in white in Figure 14) become candidate shrinkage areas, so the shaded area indicated by reference numeral 57 in Figure 26 is determined to be a candidate shrinkage area. Since the data values ​​of all pixels are 0 for all color plate data, there are no areas (pixels) that are determined to be colored areas in step S320 above.

[0097] In step S330 above, based on the second white plate data W2, the area represented in white in Figure 13 is designated as the area to be filled. In step S340, the aforementioned 3x3 shrink filter is applied to each pixel included in the area to be filled. The area represented in white in Figure 14 is obtained by the shrinking process using this 3x3 shrink filter. As described above, the area before shrinking by the shrinking process (here, the area represented in white in Figure 13) excluding the area after shrinking by the shrinking process (here, the area represented in white in Figure 14) becomes the area permitted to shrink, so the same area as the candidate area for shrinking (shaded area 57 in Figure 26) is designated as the area permitted to shrink.

[0098] The final area to be contracted is the area representing the logical AND of the contraction candidate area, the colored area, and the contraction permitted area. The contraction candidate area and the contraction permitted area are the shaded area 57 in Figure 26, and there are no areas defined in the colored area, so there is no final area to be contracted.

[0099] Therefore, the white outline characters shown in Figure 13 are not shrunk. Consequently, the white outline characters are printed with the desired thickness. In this example as well, similar to the processing for white characters, the white outline character shrunk process may be terminated after the completion of step S320 without performing steps S330 to S360.

[0100] <5.2.4 Handling cases where regular shapes and white text are mixed> Next, we will explain what processing is performed when regular graphics and white text are mixed. Here, we will focus on the case shown in Figure 27. For the second white plate data W2, the data values ​​of the pixels included in the shaded area indicated by symbols 60 and 61 in Figure 27 are non-zero, and the data values ​​of the other pixels are 0. For the K plate data, the data values ​​of the pixels included in the shaded area indicated by symbol 61 in Figure 27 are non-zero, and the data values ​​of the other pixels are 0. Note that for color plate data other than the K plate data, we assume that the data values ​​of all pixels are 0.

[0101] In step S310 above, the aforementioned 3x3 shrink filter is applied to each pixel included in the shaded areas 60 and 61 in Figure 27. With respect to the second white plate data W2, the data values ​​of the pixels included in the shaded areas 60 and 61 in Figure 27 are non-zero, and the data values ​​of the other pixels are 0, so the shaded area indicated by reference numeral 62 in Figure 28 is determined to be a candidate shrink area. In step S320 above, based on the K plate data, the shaded area indicated by reference numeral 63 in Figure 29 is determined to be a colored area.

[0102] In step S330 above, based on the second white plate data W2 and the K plate data, the shaded areas 60 and 61 in Figure 27 are defined as the areas to be filled. In step S340, the 3x3 shrink filter described above is applied to each pixel included in the areas to be filled. The shrinking process using this 3x3 shrink filter yields the white area labeled 65 in Figure 28. As described above, the areas before shrinking by the shrinking process (in this case, the shaded areas 60 and 61 in Figure 27) excluding the areas after shrinking by the shrinking process (in this case, the white area 65 in Figure 28) become the areas permitted for shrinking, so the same area as the candidate area for shrinking (shaded area 62 in Figure 28) is defined as the areas permitted for shrinking.

[0103] The final region to be contracted is the region representing the logical AND of the candidate region to be contracted, the colored region, and the region to be contracted. The candidate region to be contracted and the region to be contracted are the shaded region 62 in Figure 28, and the colored region is the shaded region 63 in Figure 29, so the final region to be contracted is the shaded region indicated by reference numeral 64 in Figure 30.

[0104] Based on the above, with respect to the pixels that form the white plate shapes (pixels included in the shaded areas 60 and 61 in Figure 27), white ink is not applied to the pixels within the shaded area 64 in Figure 30 during printing, while white ink is applied to the other pixels during printing. As a result, even if misregistration occurs between the white plate and the K plate, the desired shrinkage process is performed on the white plate shapes, suppressing the appearance of white streaks around the black rectangular shapes based on the K plate data. Furthermore, since no shrinkage is performed on the white text, the white text is printed with the desired thickness.

[0105] Similarly, when regular shapes, white text, and outlined text are mixed appropriately, the desired shrinkage process is applied to the white shapes that make up the regular shapes, while the white text and outlined text are not.

[0106] <5.2.5 Processing of data containing areas where white-ink and color-ink graphics overlap> This section describes the processing of cases where an overlapping area (hereinafter referred to as the "overlap area") between the white plate graphic and the K plate graphic is intentionally provided, in cases other than those where white ink is used as the base layer. Here, we focus on the case where the white plate graphic shrinkage process is performed based on the second white plate data W2 shown in Figure 15 and the K plate data shown in Figure 16 (the area other than the shaded area indicated by reference numeral 66 is the area that should be filled with black ink). Note that for the color plate data other than the K plate data, it is assumed that the data value of all pixels is 0.

[0107] In step S310 above, the aforementioned 3x3 shrink filter is applied to each pixel represented in white in Figure 15. With respect to the white plate data, the data value of the pixels represented in white in Figure 15 is a value other than 0, and the data value of the other pixels is 0. Therefore, the shrink process yields the area represented in white in Figure 17. As described above, the area before shrinkage by the shrink process (here, the area represented in white in Figure 15) excluding the area after shrinkage by the shrink process (here, the area represented in white in Figure 17) becomes the candidate area for shrinkage, so the shaded area 69 in Figure 17 is determined to be the candidate area for shrinkage. In step S320 above, based on the K plate data, the area other than the shaded area 66 in Figure 16 is determined to be the colored area.

[0108] In step S330, the entire printing area is defined as the area to be filled based on the second white plate data W2 and the colored area obtained in step S320. In step S340, the aforementioned 3x3 shrink filter is applied to each pixel included in the area to be filled (i.e., all pixels within the printing area). The area represented in white in Figure 31 is obtained by the shrinking process using this 3x3 shrink filter. As described above, the area before shrinking by the shrinking process (in this case, the entire printing area) excluding the area after shrinking by the shrinking process (in this case, the area represented in white in Figure 31) becomes the shrink-permitted area, so the shaded area indicated by reference numeral 71 in Figure 31 is defined as the shrink-permitted area. For convenience, Figure 31 is assumed to show the pixels of the entire printing area.

[0109] The final area to be contracted is the area representing the logical AND of the contraction candidate area, the colored area, and the contraction permitted area. The contraction candidate area is the shaded area 69 in Figure 17, the colored area is the area other than the shaded area 66 in Figure 16, and the contraction permitted area is the shaded area 71 in Figure 31, so there is no final area to be contracted.

[0110] Therefore, no shrinkage of the white ink plate occurs in the overlapping area described above. Consequently, during printing, black ink is applied on top of the white ink in the overlapping area. Thus, even if misregistration occurs between the white plate and the black plate, as long as the size of the misregistration is within the width of the overlapping area, the desired printing result can be obtained (the color of the substrate will not appear).

[0111] <6. Shape modification process> According to the procedure shown in Figure 6, the white plate data (second white plate data W2) is subjected to a white plate shape reduction process, resulting in faster white plate shape reduction compared to conventional methods. However, the white plate data obtained by re-enhancing the white plate data after the white plate shape reduction process (fourth white plate data W4) has the following two problems (the first and second problems).

[0112] The first problem is that the width of shapes such as thin lines can become thicker than their original width (width immediately after RIP processing) when white plate data is de-resolution or re-resolution. For example, suppose that the white plate data before de-resolution (first white plate data W1) has a resolution of 1200 dpi and contains a thin line that is 2 pixels wide. When the white plate data (first white plate data W1) is de-resolution from 1200 dpi to 200 dpi, the averaging process described above is performed, so the thin line does not disappear but becomes a thin line that is 1 pixel wide. Subsequently, when the white plate data after white plate shape shrinkage processing (third white plate data W3) is re-resolution from 200 dpi to 1200 dpi, the 1-pixel wide thin line becomes a thin line that is 6 pixels wide. Specifically, when the first white plate data W1 shown in Figure 32 (where the black areas in Figure 32 represent the areas to be coated with white ink) is subjected to a low-resolution process, the second white plate data W2 shown in Figure 33 is generated. Subsequently, the second white plate data W2 is subjected to a white plate graphic reduction process, and then the third white plate data W3 obtained from the white plate graphic reduction process is subjected to a high-resolution process, generating the fourth white plate data W4 shown in Figure 34. The shapes indicated by the arrows labeled 73 in Figure 32 are appropriately thinned to the shapes indicated by the arrows labeled 75 in Figure 34. In contrast, the shapes indicated by the arrows labeled 74 in Figure 32 have had their line widths increased to the shapes indicated by the arrows labeled 76 in Figure 34. As described above, the line width of thin lines, in particular, can become thicker due to the low-resolution process, the white plate graphic reduction process, and the high-resolution process.

[0113] The second problem is that the reduction and resizing of white plate data can result in blurred printed images based on white plate graphics. In this regard, sometimes print data (first print data) is generated so that a white image appears as a printed image by applying only white ink to a certain area without applying process color ink. When the white plate data constituting such first print data is subjected to reduction in resolution using averaging and resizing using nearest neighbor interpolation, the smoothness of the outlines of the white plate graphics is impaired. For example, if the white plate graphics labeled 80 in section A of Figure 35 are subjected to reduction and resizing as is, they will become graphics with blurred outlines, like the graphics labeled 81 in section B of Figure 35. As described above, reduction in resolution, white plate graphic shrinkage processing, and resizing can result in blurred printed images based on white plate graphics.

[0114] Therefore, in step S50 of Figure 6, in order to resolve the two problems mentioned above, a shape correction process is performed to modify the white plate shapes (fourth white plate shapes) included in the high-resolution white plate data (fourth white plate data W4).

[0115] In the shape correction process, the first step is to resolve the first problem. Specifically, a masking process is applied to the white plate shapes in the high-resolution white plate data (fourth white plate data W4) using the white plate shapes in the white plate data immediately after RIP processing (first white plate data W1) so that the portion of the white plate shapes in the high-resolution white plate data (fourth white plate data W4) that corresponds to the area outside the outline of the white plate shapes in the white plate data immediately after RIP processing (first white plate data W1) is deleted. This masking process restores the width of the shapes that have become thicker due to resolution conversion (lower resolution and higher resolution) to their original width (width immediately after RIP processing). For example, the shape indicated by the arrow labeled 76 in Figure 34 (the shape that has become thicker due to resolution conversion) becomes the shape indicated by the arrow labeled 78 in Figure 36 after this masking process. The width of the shape indicated by the arrow labeled 78 in Figure 36 is equal to the width of the shape indicated by the arrow labeled 74 in Figure 32 (the shape immediately after RIP processing). In this way, the first problem is resolved.

[0116] Furthermore, for shapes that have been appropriately thinned by the white ink shape shrinking process, no unnecessary processing will be applied by the masking process. For example, the shape indicated by the arrow labeled 75 in Figure 34 will become the shape indicated by the arrow labeled 77 in Figure 36 after the masking process is complete. The shape indicated by the arrow labeled 75 in Figure 34 and the shape indicated by the arrow labeled 77 in Figure 36 are the same shape.

[0117] In the shape correction process, the next step is to address the second problem. In this regard, white plate shapes that do not overlap with color plate shapes do not cause white streaks due to misregistration, so there is no need to shrink them. Therefore, for white plate shapes that do not overlap with color plate shapes, the data value (pixel value) of each pixel after high resolution is replaced with the data value (pixel value) immediately after RIP processing. Specifically, in areas where white plate shapes and color plate shapes do not overlap, the data value (pixel value) in the high-resolution white plate data (fourth white plate data W4) is replaced with the data value (pixel value) in the white plate data immediately after RIP processing (first white plate data W1). As a result, for white plate shapes that do not overlap with color plate shapes, shapes whose outlines were blurred due to resolution conversion become shapes with sharp outlines. For example, let's assume that the RIP processing of the submitted data DIN generates print data (first print data) as shown in part A of Figure 37. The print data shown in section A of Figure 37 includes a white plate figure denoted by reference numeral 82 and a color plate figure denoted by reference numeral 83. If printing is performed without applying any graphic correction processing to the white plate data after high-resolution processing, a print image like the one shown in section B of Figure 37 will be obtained. In section B of Figure 37, the white plate figure denoted by reference numeral 84 has a blurred outline. In this embodiment, the graphic correction processing replaces the white plate figure in the area of ​​the entire region shown in section B of Figure 37, excluding the part denoted by reference numeral 83, with the white plate figure immediately after RIP processing. Therefore, a print image like the one shown in section A of Figure 37 is obtained. In this way, the second problem is resolved.

[0118] <7. Effects> According to this embodiment, a white plate shape reduction process is performed on the white plate data after low-resolution processing (second white plate data W2), which is a process that makes the white plate shape smaller than the color plate shape so that the appearance of white streaks around the shape due to misregistration is suppressed. As a result, the number of pixels to be processed in the white plate shape reduction process is reduced compared to the conventional method. Therefore, the time required for the white plate shape reduction process is shortened. Here, a resolution conversion process (low-resolution and high-resolution) is added, but by appropriately selecting the algorithm used for the resolution conversion process, the overall processing time involved in generating the final print data can be shortened. In addition, a shape correction process is applied to the white plate data after high-resolution processing (fourth white plate data W4) so ​​as to suppress the deterioration of print quality caused by the resolution conversion. As a result, it is possible to shorten the overall processing time involved in generating the final print data compared to the conventional method (i.e., speed up the process of generating the final print data) while maintaining sufficient print quality.

[0119] Here, we present the results of an experiment comparing the time required from the start of RIP processing to obtaining the final print data (print data to be provided to the printing device) (hereinafter referred to as "print data generation time") between the conventional method and the method of this embodiment. In one case where the non-shrinkable width was set to 0 mm and white plate graphic shrinkage processing was performed, the print data generation time with the conventional method was 26 seconds, while the print data generation time with the method of this embodiment was 8 seconds. In another case where the non-shrinkable width was set to 0.4 mm and white plate graphic shrinkage processing was performed, the print data generation time with the conventional method was 10 minutes and 19 seconds, while the print data generation time with the method of this embodiment was 9 seconds. Thus, regardless of whether or not the non-shrinkable width is set, the print data generation time is significantly reduced.

[0120] As described above, according to this embodiment, with respect to printing using process color ink and white ink, it is possible to shorten the time required to generate the final print data (print data to be provided to the inkjet printing device 10) without degrading the print quality.

[0121] <8. Variation> The following describes modifications of the above embodiment.

[0122] <8.1 First variation> First, a modified example of the graphic correction process in step S50 of Figure 6 will be described as the first modified example of the above embodiment. In this modified example, the data values ​​of pixels whose data values ​​(pixel values) are other than 0 in the high-resolution white plate data (fourth white plate data W4) are replaced with the data values ​​in the white plate data immediately after RIP processing (first white plate data W1), thereby generating the white plate data (fifth white plate data W5) to be given to the inkjet printing device 10.

[0123] According to this modified example, for shapes that have been appropriately thinned by the processing up to step S40 in Figure 6, the data value in the fourth white plate data W4 for each pixel in the area that is not subject to white ink application is 0. Therefore, there is no change in the shape of the shape before and after the shape correction process. For shapes that have become thicker due to resolution conversion, the data value of each pixel in the area that has changed from being subject to white ink application to being subject to white ink application is replaced from a value other than 0 to 0, so the shape becomes the original width (width immediately after RIP processing). In this way, the same effect as masking is obtained.

[0124] Furthermore, according to this modified version, regardless of the presence or absence of color graphics, the data values ​​of pixels whose data values ​​after high-resolution processing are not zero are all replaced with the data values ​​immediately after RIP processing. As a result, graphics whose outlines are blurred due to resolution conversion will become graphics with sharp outlines after the graphics correction process.

[0125] As described above, this modified example also resolves the first and second problems mentioned above.

[0126] <8.2 Second variation> In the above embodiment, a process was performed to shrink the white plate shape, but the present invention is not limited to this, and a process may be performed to shrink the base map shape corresponding to the area to be coated with primer. That is, the print data processing procedure shown in Figure 6 may be applied to raster data consisting of base data and color plate data, which are data for primer application. This will be described below as a second modification of the above embodiment. The base data generated by the RIP process is called the "first base data," and the shape represented by the first base data that corresponds to the area to be coated with primer is called the "first base map shape." Furthermore, the process corresponding to the white plate shape shrinking process in the above embodiment is called the "base map shape shrinking process."

[0127] In this modified example, after the start of print data processing, first, the first background data containing the first background map shape is subjected to a low-resolution process (step S10). This generates second background data containing the second background map shape corresponding to the first background map shape. Next, the second background data is subjected to a shrink / expansion process (step S20). This generates determination data for determining whether each second background map shape contained in the second background data is a shape that is not subject to shrinkage in the background map shape shrinkage process. Next, while referring to the determination data, the second background map shape contained in the second background data is subjected to a background map shape shrinkage process (step S30). This generates third background data containing the third background map shape. Next, the third background data is subjected to a high-resolution process (step S40). This generates fourth background data containing the fourth background map shape corresponding to the third background map shape. Next, to suppress the decrease in print quality caused by the shrinkage of the base map shape using the lower-resolution base data (second base data), a graphic correction process is performed on the base map shape (fourth base map shape) included in the higher-resolution base data (fourth base data) (step S50). This generates the fifth base data, which includes the fifth base map shape. Finally, the color plate data PD and the fifth base data generated in step S50 are output to the inkjet printing device 10 (step S60).

[0128] According to the above modification, in cases where the area to which the primer is applied is treated as part of the printed image, it is possible to shorten the time required to generate the final print data (print data to be provided to the inkjet printing device 10) without degrading the print quality.

[0129] <8.3 Modifications related to white ink graphic reduction processing> Modifications of the white ink graphic shrinkage process are described below as the third to fifth modifications of the above embodiment.

[0130] <8.3.1 Third variation> In the above embodiment, the white ink shape shrinkage process is performed so that the shape of the white ink shape becomes thinner. In other words, the white ink shape shrinkage process ensures that no white ink is applied at all to the pixels within the final shrinkage target area during printing. However, the present invention is not limited to this, and the amount of white ink applied to the pixels within the final shrinkage target area during printing may be less than the original application amount.

[0131] In this regard, let us assume, for example, that "for each plate data, the data value of each pixel can take values ​​from 0 to 255, and for white plate data, the data value of pixels to be coated with white ink is set to 255, and the data value of pixels not to be coated with white ink is set to 0." In such a case, in this modified example, the data value of pixels within the final shrinkage target area of ​​the white plate data is rewritten from "255" to, for example, "128" in step S360 above. As a result, for pixels within the final shrinkage target area, only half the original amount of white ink is applied during printing. In this way, the white plate graphic can be pseudo-thinned by 0.5 pixels in a low-resolution state.

[0132] <8.3.2 Fourth variation> In the above embodiment, the shrinking process is performed so that the white ink figure to be shrunk becomes thinner by 1 pixel at its periphery in a low-resolution state. However, the present invention is not limited thereto, and the shrinking process may be performed so that the white ink figure becomes thinner by 2 or more pixels at its periphery in a low-resolution state.

[0133] In this regard, for example, if the goal is to reduce the thickness of a white graphic by 2 pixels in a low-resolution state through shrinkage processing, in step S310 above, a 5x5 shrinkage filter may be applied to each pixel instead of a 3x3 shrinkage filter, or a 3x3 shrinkage filter may be applied to each pixel first, and then the 3x3 shrinkage filter may be applied to each pixel again. Thus, known methods can be used for applying the shrinkage filter itself.

[0134] <8.3.3 Fifth variation> The above embodiment assumes that printing is performed using ordinary process color inks and white ink. However, the present invention can also be applied when printing is performed using special color inks (other than white) in addition to these inks. For example, suppose that in a certain printing system, gold ink is used in addition to ordinary process color inks and white ink during printing (here, the plate data for the gold ink is referred to as "G plate data"). In this case, in step S320 of Figure 20, the area representing the logical OR of the C plate data, M plate data, Y plate data, K plate data, and G plate data should be determined as the colored area.

[0135] <9. Others> The present invention is not limited to the above embodiments (including modifications), and can be implemented in various modified forms without departing from the spirit of the invention. For example, although the above embodiments described a case in which a figure (white plate figure) corresponding to an area coated with white ink shrinks, the present invention can also be applied to a case in which a figure corresponding to an area coated with metallic ink such as silver ink shrinks.

[0136] <10. Addendum> Based on the above disclosures, a print data processing device with the configuration described below is also conceivable.

[0137] A print data processing device that processes print data which is raster data consisting of process color data including a main figure corresponding to an area to be coated with process color ink and first specific color data including a first specific color figure corresponding to an area to be coated with ink of a specific color other than process color, Processor and The memory that stores the program and Equipped with, A print data processing device characterized in that, when the program stored in the memory is executed by the processor, the program causes the processor to perform the following operations (A), (B), (C), and (D): (A) By reducing the resolution of the first specific color data, a second specific color data is generated which includes a second specific color figure corresponding to the first specific color figure. (B) A third specific color data including a third specific color figure is generated by applying a shrinkage process to the second specific color figure. (C) By increasing the resolution of the third specific color data, a fourth specific color data is generated which includes a fourth specific color figure corresponding to the third specific color figure. (D) A fifth specific color data is generated, which includes a fifth specific color figure, by replacing the fourth specific color figure with the first specific color figure in at least a portion of the overall area corresponding to the fourth specific color data. [Explanation of Symbols]

[0138] 6…Print data processing program 10…Inkjet printing equipment 30…Print data generation device 31…RIP Processing Unit 32...Reduced resolution section 33... Contraction / Expansion Section 34... White plate graphic shrinkage processing unit 35…High-resolution section 36…Shape Correction Section 37…Print data output section 100... Printer body 200…Printing control device DIN…Submission data PD…Color plate data W1~W5…White plate data for the 1st to 5th generations WD…Data for contraction determination

Claims

1. A method for processing print data which is raster data comprising process color data including a main figure corresponding to an area to be coated with process color ink, and first specific color data including a first specific color figure corresponding to an area to be coated with ink of a specific color other than process color, A low-resolution step of generating second specific color data including a second specific color figure corresponding to the first specific color figure by reducing the resolution of the first specific color data, A specific color figure shrinking step that generates third specific color data including a third specific color figure by applying a shrinking process to the second specific color figure, A high-resolution step of generating a fourth specific color data that includes a fourth specific color figure corresponding to the third specific color figure by increasing the resolution of the third specific color data, A figure modification step to generate fifth specific color data including a fifth specific color figure by replacing the fourth specific color figure in at least a portion of the overall area corresponding to the fourth specific color data with the first specific color figure, and A method for processing print data, characterized by including the following:

2. The printing data processing method according to claim 1, characterized in that in the figure modification step, a masking process using the first specific color figure is applied to the fourth specific color figure so that the portion of the fourth specific color figure that is outside the outline of the first specific color figure is deleted, thereby generating the fifth specific color data including the fifth specific color figure.

3. The print data processing method according to claim 1, characterized in that in the figure modification step, the pixel values ​​in the fourth specific color data are replaced with the pixel values ​​in the first specific color data in areas where the fourth specific color figure and the main figure do not overlap, thereby generating the fifth specific color data including the fifth specific color figure.

4. The printing data processing method according to claim 1, characterized in that, in the figure modification step, a masking process is applied to the fourth specific color figure using the first specific color figure so that the portion of the fourth specific color figure corresponding to the area outside the outline of the first specific color figure is deleted, and in the area where the fourth specific color figure and the main figure do not overlap, the pixel values ​​in the fourth specific color data are replaced with the pixel values ​​in the first specific color data so that the fifth specific color data including the fifth specific color figure is generated.

5. The print data processing method according to claim 1, characterized in that in the figure modification step, the pixel values ​​of pixels in the fourth specific color data that have pixel values ​​other than 0 are replaced with the pixel values ​​in the first specific color data, thereby generating the fifth specific color data including the fifth specific color figure.

6. The process includes a reduction and expansion step, which occurs after the reduction in resolution step and before the reduction in specific color shape step, in which the second specific color shape is reduced by a first width, which is a threshold for distinguishing whether or not to include the second specific color shape in the reduction process in the reduction in specific color shape step, and then expanded by the first width to generate data for reduction determination, The print data processing method according to any one of claims 1 to 5, characterized in that, in the specified color figure shrinking step, a second specified color figure whose corresponding figure is not included in the shrinking determination data is excluded from the shrinking process.

7. A method for processing print data according to any one of claims 1 to 5, characterized in that, with respect to the first specific color data, M and N are natural numbers, the lower resolution step involves calculating the average value of the pixel values ​​for each (M × N) pixel, thereby generating second specific color data in which the resolution of the first specific color data is multiplied by 1 / M in the horizontal direction and by 1 / N in the vertical direction.

8. The printing data processing method according to any one of claims 1 to 5, characterized in that the fourth specific color data is generated by increasing the resolution of the third specific color data using the nearest neighbor interpolation method in the high-resolution step.

9. The printing data processing method according to any one of claims 1 to 5, further comprising a printing data output step of outputting the process color data and the fifth specific color data to a printing device.

10. The printing data processing method according to any one of claims 1 to 5, characterized in that the specified color is white.

11. The aforementioned specific color figure contraction step is, A step to calculate a contraction candidate region, which is a candidate region for contracting the second specific color figure included in the second specific color data, A colored area calculation step in which the colored area, which is the area to be coated with process color ink, is determined based on the process color data, A painting target area calculation step in which a set of pixels included in at least one of the colored area and the area to be coated with the specific color ink based on the second specific color data is determined as the painting target area, A shrinkage permission area calculation step is to determine a shrinkage permission area, which is an area in which the shrinkage of the second specific color figure included in the second specific color data is permitted, by applying a shrinkage process to the area to be painted. A step to identify a region to be reduced, which defines the region of pixels included in all of the candidate region to be reduced, the colored region, and the permitted region to be reduced as the region to be reduced, A specific color data update step that generates the third specific color data by rewriting the pixel values ​​of pixels included in the shrinkage target region of the second specific color data so that the amount of ink of the specific color applied to those pixels is reduced. A method for processing print data according to any one of claims 1 to 5, characterized by including the following:

12. A method for processing print data which is raster data comprising image data including a main shape corresponding to an area to be coated with image forming ink and first base data including a first base map shape corresponding to an area to be coated with base paint, A low-resolution step of generating second background data including a second background map shape corresponding to the first background map shape by reducing the resolution of the aforementioned background data, A specific color shape shrinking step that generates a third background data including a third background map shape by applying a shrinking process to the second background map shape, A high-resolution step of generating a fourth background data including a fourth background map shape corresponding to the third background map shape by increasing the resolution of the third background data, A graphic modification step to generate a fifth background data including a fifth background shape by replacing the fourth background map shape with the first background map shape in at least a portion of the overall area corresponding to the fourth background data; A method for processing print data, characterized by including the following:

13. A print data processing device that processes print data which is raster data consisting of process color data including a main figure corresponding to an area to be coated with process color ink and first specific color data including a first specific color figure corresponding to an area to be coated with ink of a specific color other than process color, A low-resolution means for generating second specific color data including a second specific color figure corresponding to the first specific color figure by reducing the resolution of the first specific color data, A specific color figure shrinking means that generates a third specific color data including a third specific color figure by applying a shrinking process to the second specific color figure, A high-resolution means for generating a fourth specific color data including a fourth specific color figure corresponding to the third specific color figure by increasing the resolution of the third specific color data, A graphic modification means that generates a fifth specific color data including a fifth specific color figure by replacing the fourth specific color figure in at least a portion of the overall area corresponding to the fourth specific color data with the first specific color figure, and A print data processing device characterized by comprising:

14. A printing system comprising: a printing data processing device that generates second printing data by processing first printing data which is raster data consisting of process color data including a main figure corresponding to an area to be coated with process color ink and first specific color data including a first specific color figure corresponding to an area to be coated with a specific color ink other than process color; and a printing device that prints on a printing medium based on the second printing data, The print data processing device is A low-resolution means for generating second specific color data including a second specific color figure corresponding to the first specific color figure by reducing the resolution of the first specific color data, A specific color figure shrinking means that generates a third specific color data including a third specific color figure by applying a shrinking process to the second specific color figure, A high-resolution means for generating a fourth specific color data including a fourth specific color figure corresponding to the third specific color figure by increasing the resolution of the third specific color data, A graphic modification means for generating fifth specific color data including a fifth specific color figure by replacing the fourth specific color figure in at least a portion of the overall area corresponding to the fourth specific color data with the first specific color figure, A print data output means that outputs the process color data and the fifth specific color data as the second print data to the printing device. Equipped with, The aforementioned printing apparatus, A transport mechanism for transporting the aforementioned printing medium, A first printing unit that ejects process color ink onto the printing medium being transported by the transport mechanism based on the process color data, A first fixing unit that fixes the ink ejected from the first printing unit onto the printing medium, A second printing unit that ejects ink of the specified color onto the printing medium being transported by the transport mechanism based on the fifth specified color data, A printing system characterized by comprising a second fixing unit for fixing ink ejected from the second printing unit onto the printing medium.

15. A print data processing program that processes print data which is raster data consisting of process color data including a main figure corresponding to the area to be coated with process color ink and first specific color data including a first specific color figure corresponding to the area to be coated with ink of a specific color other than process color, On the computer, A low-resolution step of generating second specific color data including a second specific color figure corresponding to the first specific color figure by reducing the resolution of the first specific color data, A specific color figure shrinking step that generates third specific color data including a third specific color figure by applying a shrinking process to the second specific color figure, A high-resolution step of generating a fourth specific color data that includes a fourth specific color figure corresponding to the third specific color figure by increasing the resolution of the third specific color data, A figure modification step to generate fifth specific color data including a fifth specific color figure by replacing the fourth specific color figure in at least a portion of the overall area corresponding to the fourth specific color data with the first specific color figure, and A program for processing print data to execute the print operation.

Images