JP2010017953A - Printed material forming method, printed material forming system and printed material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the uniformity of the texture of a printed material formed by generating two printed images on one printing surface using two different sets of printing equipment. <P>SOLUTION: The improvement of the uniformity of the texture of the whole printed material can be achieved by generating the second printed image whose sharpness approximates to that of the first printed image more than that of a printed image in the case that no sharpness processing is applied to a second image on a printing paper in a state that, in a printed material forming system 1, the sharpness processed second image is generated by performing sharpness processing for enhancing the sharpness of the second image at a processing part 5 at the printing of the second image by an ink-jet printer 4 on one printing paper on which a first image has been printed by an offset printing machine 2, and then printing is performed according to data of the processed second image by the ink-jet printer 4. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technique for creating a printed material in which a plurality of images are printed on the same printing surface by a plurality of printing apparatuses, and the printed material.

  When printing an original image with multiple gradations (that is, continuous gradation), AM (Amplitude Modulated) screening in which gradation expression is realized by changing the size of regularly arranged halftone dots, irregularities, etc. FM (Frequency Modulated) screening is used in which gradation expression is realized by changing the number of halftone dots of a certain size arranged in recent years. Recently, the size of irregularly arranged halftone dots is used. A technique for realizing gradation expression by changing the height is also used.

  When printing is actually performed, a threshold matrix is prepared in which a plurality of elements are arranged in a row direction and a column direction and a threshold value is assigned to each element, and printing is performed by comparing the original image and the threshold matrix. A halftone image to be used is generated. Such halftone images are subject to plate printing such as screen printing, offset printing, gravure printing, flexographic printing, letter press printing, or plateless printing using a printing apparatus such as an ink jet method or an electrophotographic method. Printed on the object. With plate printing, it is possible to create a large number of printed materials at high speed. With plateless printing, it is possible to print an image directly according to image data without creating a plate necessary for plate printing. It becomes possible.

  As a technique for improving the image quality of a printed matter, in Patent Document 1, with respect to any one of a density area, a hue area, and a coordinate area, a halftone dot is formed while changing the halftone dot shape of the area according to the band of each area of the image. A technique for recording an image is disclosed. Further, in Patent Document 2, a plurality of attribute areas are defined by dividing a range that can be taken by any attribute of a coordinate area, a density area, a hue area, and a spatial frequency area, and each pixel has any attribute. A halftone dot image is determined by selecting one of a plurality of halftone dot types including a binary halftone dot and a larger multivalued halftone dot based on the determination result. A technique for recording is disclosed.

Also, p. 235 discloses a method for obtaining an evaluation value related to sharpness. In this method, first, an average value of absolute values of density differences from 8 neighboring pixels is obtained as H for each pixel of an image, and the horizontal axis represents A cumulative histogram indicating the value of H and the number of pixels on the vertical axis is generated as a delta histogram. Subsequently, an averaged image obtained by applying a Gaussian filter to the image is generated, and a delta histogram is similarly obtained in the averaged image. A value indicating the difference between the two delta histograms is an evaluation value related to sharpness.
JP-A 61-285867 JP 2000-33014 A Fumihiko Saito, “Improvement of image contrast by density gradient histogram”, Denki Theory C, 2006, Vol. 126, No. 2, p. 228-236

  By the way, when sending an advertisement to a customer by direct mail, if a part of the advertisement is changed for each customer according to the customer's preference, etc. The same image is printed, and an individual image is further printed for each printing paper by so-called plateless printing (so-called reprinting). For example, an inkjet printing apparatus having a recording resolution of 600 to 720 dpi, in which a binary image is printed on a printing sheet by a printing apparatus for offset printing using a printing plate having a recording resolution of 2400 dpi (dot per inch). Even when printing images on the same printing paper by performing multi-value control (that is, drawing control of two or more sizes of dots) at, in recent years due to improved performance of plateless printing devices, both printing The apparatus can print with good image quality.

  However, in reality, high-resolution offset printing using oil-based inks causes less blurring of the printed image than ink-jet printing devices that use water-based ink, and forms sharper print images than ink-jet printing devices. The Therefore, when printing is performed on the same printing surface with these printing devices (so-called hybrid printing), the sharpness of the printed image is different and the texture of the printed material is non-uniform, causing the viewer to feel uncomfortable. There is.

  The present invention has been made in view of the above problems, and an object thereof is to improve the uniformity of the texture of a printed matter created by forming two print images on the same print surface with two different printing apparatuses. .

  The invention according to claim 1 is a printed material creating method for creating a printed material in which the first image and the second image are printed on the same printing surface, and a) a printing plate showing the first image is printed in the printing apparatus. Printing using or printing according to the data of the first image to form the first print image on the printing surface of the print medium; and b) applying a sharpness changing process to the second image. Generating a processed second image; and c) printing using a printing plate representing the processed second image in another printing apparatus different from the printing apparatus, or the processed second image By performing printing according to image data, a second printed image whose sharpness is closer to the first printed image than the printed image when the sharpness changing process is not performed on the second image is printed on the printing surface. And forming.

  The invention according to claim 2 is the printed matter creation method according to claim 1, wherein d) printing is performed using a printing plate showing a predetermined test image in each of the printing apparatus and the another printing apparatus. Or forming two test print images respectively corresponding to the printing device and the other printing device on the same or different printing media by performing printing according to the data of the test image, and e) Capturing each of the two test print images and obtaining a difference in sharpness between the two test print images, and in step b), based on the difference in sharpness between the two test print images. Then, the sharpness changing process is performed on the second image.

  According to a third aspect of the present invention, there is provided the printed matter creating method according to the second aspect, wherein a difference in sharpness between two test print images respectively corresponding to the printing apparatus and the other printing apparatus, and a plurality of filters Is prepared in advance, and one filter is identified by referring to the filter information using the difference in sharpness between the two test print images acquired in step e). In the step b), the sharpness changing process is performed on the second image using the filter.

  The invention according to claim 4 is the printed material creating method according to any one of claims 1 to 3, wherein the printing apparatus performs printing using a printing plate showing the first image. The other printing apparatus is a plateless printing apparatus that performs printing according to the data of the processed second image.

  The invention according to claim 5 is the printed matter creation method according to claim 4, wherein the another printing apparatus is an ink jet printing apparatus, and in step b), the sharpness of the second image is obtained. The processed second image is generated by performing the sharpness changing process for enhancing the image quality.

  The invention according to claim 6 is a printed matter creation system for creating a printed matter in which the first image and the second image are printed on the same printing surface, and printing is performed using a printing plate showing the first image. Alternatively, by printing according to the data of the first image, a printing device that forms the first print image on the print surface of the print medium and a second image that has been processed by applying sharpness change processing to the second image are generated. Printing using a printing plate showing the processed second image and the processed second image, or by printing according to the data of the processed second image, the sharpness changing process is performed on the second image. And a second printing device that forms a second print image on the print surface, the sharpness of which is closer to that of the first print image than when the print image is not printed.

  A seventh aspect of the present invention is the printed matter creation system according to the sixth aspect, wherein a printing plate showing a predetermined test image is used as test printing in each of the printing apparatus and the another printing apparatus. By performing printing or printing according to the data of the test image, two test print images respectively corresponding to the printing device and the other printing device are formed on the same or different print media, and the two By capturing each of the test print images, a difference in sharpness between the two test print images is acquired, and the processing unit adds the sharpness to the second image based on the difference in sharpness between the two test print images. Apply the change process.

  The invention according to claim 8 is the printed matter creation system according to claim 7, wherein a difference in sharpness between two test print images respectively corresponding to the printing apparatus and the another printing apparatus, and a plurality of filters are provided. A storage unit that stores filter information indicating the association with the image data, and the processing unit refers to the filter information using a difference in sharpness between the two test print images acquired by the test printing. One filter is specified by the above, and the sharpness changing process is performed on the second image using the filter.

  A ninth aspect of the present invention is the printed matter creation system according to the seventh or eighth aspect, further comprising an imaging unit that captures the two test print images acquired by the test printing, and the printing apparatus And the another printing apparatus is arranged along a conveyance path of the print medium, and the imaging unit is arranged on the downstream side of the printing apparatus and the other printing apparatus in the conveyance path.

  A tenth aspect of the present invention is formed by the printed matter producing method according to any one of the first to fifth aspects.

  According to the present invention, it is possible to improve the uniformity of the texture of a printed matter by approximating the sharpness of two printed images respectively formed on the same printing surface by two different printing apparatuses.

  In the inventions of claims 2 and 7, the sharpness of two printed images formed on the same printing surface can be approximated with high accuracy. In the inventions of claims 3 and 8, the filter used in the sharpness changing process is used. Can be easily identified.

  Further, in the invention of claim 5, even when a plate printing device and an ink jet type printing device are used, the uniformity of the texture of the printed matter can be improved by increasing the sharpness of the second image. In this invention, the difference in sharpness between the two test print images can be obtained with high accuracy by acquiring the image data with the same image pickup unit.

  FIG. 1 is a block diagram showing a configuration of a printed material creation system 1 according to an embodiment of the present invention. The printed matter creating system 1 creates a printed matter by printing the same image on a large number of printing papers with a plate printing device and printing individual images for each printing paper with a plateless printing device.

  1 includes an offset printing machine 2 that performs printing on printing paper using a printing plate, a plate making apparatus 3 that creates a printing plate used in the offset printing machine 2, and ink that is directed toward the printing paper. Inkjet printer 4 that performs printing by ejecting minute droplets, processing unit 5 that generates drawing data in the inkjet printer 4, offset printer 2, and image storage unit 6 that stores data of an image to be printed in the inkjet printer 4 In addition, a scanner 7 for capturing an image (printed image) printed by the offset printer 2 is provided.

  The plate making apparatus 3 is realized by a control unit 31 (for example, a computer) that serves as an RIP (Raster Image Processor) that generates drawing data from image data input from the image storage unit 6 and that controls the entire plate making apparatus 3. And a plate making section 32 for recording an image on the printing plate according to the drawing data. The control unit 31 includes an image data buffer 311 that stores image data input from the image storage unit 6, a matrix storage unit 312 that stores a threshold matrix (also referred to as SPM (Screen Pattern Memory)), and an image data buffer 311. A comparison operation unit 313 that generates drawing data indicating a binary halftone image by comparing the value (pixel value) of each pixel from the pixel and a corresponding threshold value from the matrix storage unit 312.

  Similarly to the control unit 31 of the plate making apparatus 3, the processing unit 5 also includes an image data buffer 51, a matrix storage unit 52, and a comparison operation unit 53, and in addition to these components, the lines of the scanner 7 and the ink jet printer 4. A sharpness analysis unit 54 to which imaging data from the sensor 41 is input, a storage unit 55 for storing filter information 551 described later, and a sharpness processing unit 56 provided between the image data buffer 51 and the comparison calculation unit 53 are provided. In FIG. 1, the transfer path of the imaging data is indicated by a dashed arrow (the same applies to FIG. 7 described later).

  FIG. 2 is a diagram showing a flow of processing for creating a printed matter in the printed matter creating system 1. In the printed material creation system 1, first, a test image is printed as test printing in each of the offset printer 2 and the inkjet printer 4 (step S11).

  Specifically, as shown in FIG. 3, the test image is an image including many edge components (for example, a natural image such as a landscape image or a portrait image of a person), and test image data 63 indicating the test image. Is input from the image storage unit 6 to the image data buffer 311 of the plate making apparatus 3. The comparison calculation unit 313 of the control unit 31 compares the value of each pixel of the test image indicated by the test image data 63 with the threshold value of the corresponding threshold value matrix to generate drawing data indicating a binary halftone image.

  The plate making unit 32 includes a rotating drum to which the printing plate is attached, a light irradiation unit that irradiates light on the printing plate on the rotating drum, and a moving mechanism that moves the light irradiation unit in a direction parallel to the rotation axis of the rotating drum. When the control unit 31 controls each component according to the drawing data, an image indicating a test image is recorded on the printing plate with a recording resolution of 2400 dpi, for example, by irradiation with light from the light irradiation unit. The printing plate showing the test image is conveyed to the offset printing machine 2 and attached to a rotating drum of the offset printing machine 2. Then, dampening water and oil-based ink are applied to the printing plate that rotates together with the rotating drum, the ink on the printing plate is transferred to the printing paper through the intermediate transfer member, and a test printing image indicating a test image is displayed on the printing paper. It is formed. The printing paper on which the test image is printed is conveyed to the scanner 7. In FIG. 1, the conveyance path of the printing paper is indicated by a thick arrow (the same applies to FIG. 7 described later). When the test image is color, drawing data is generated for each color component of the test image, a printing plate is produced by the plate making unit 32, and printing plates having a plurality of color components are used by the offset printing machine 2. Thus, a color test image is printed on the printing paper (the same applies to the printing of the first image described later).

  Further, when a test image is printed by the inkjet printer 4, test image data 63 indicating the test image is input from the image storage unit 6 to the image data buffer 51 of the processing unit 5. Here, in the head in the inkjet printer 4, S size dots, M size dots larger than the S size, and L size dots larger than the M size can be drawn on the printing paper. 5 matrix storage unit 52 stores a plurality of threshold matrixes respectively corresponding to S size dots, M size dots, and L size dots. In the comparison operation unit 53, the value of each pixel of the test image indicated by the test image data 63 is compared with the corresponding threshold value of each threshold value matrix, whereby a value for instructing the drawing of the S size dot, the M size dot Drawing data indicating a quaternary halftone image of a value for instructing drawing, a value for instructing drawing of an L size dot, and a value for instructing non-drawing of dots is generated.

  In the head, a plurality of ejection openings are arranged at a pitch corresponding to, for example, 720 dpi, and the print paper is moved in a direction perpendicular to the arrangement direction of the ejection openings below the head, and the head according to the drawing data. By controlling the ejection of the ink (water-based ink) from the ink, a test print image indicating a test image is formed on the printing paper. Actually, the plurality of ejection openings of the head are arranged over the entire width of the printing paper, and the printing paper passes only under the head once (so-called one-pass), and is applied to the printing paper. Printing is complete. When the test image is in color, drawing data is generated for each color component of the test image, and ink ejection control is performed from the head that ejects ink of the color according to the drawing data, so that the printing paper A color test image is printed (the same applies to the printing of the second image described later).

  The test print image formed by the offset printer 2 is picked up by the scanner 7 and the picked-up data is input to the sharpness analysis unit 54 of the processing unit 5. Further, in the inkjet printer 4, the inline line sensor 41 disposed on the upper downstream side in the moving direction of the printing paper sequentially captures the portion of the test print image immediately after being formed, acquires the image data, and sharpness. The data is input to the analysis unit 54 (step S12). At this time, preferably, the reading resolutions of the scanner 7 and the line sensor 41 are made equal, and the scanner 7 and the line sensor 41 acquire grayscale imaging data. Note that color image data (that is, color components of R (red), G (green), and B (blue)) may be acquired by the scanner 7 and the line sensor 41. In this case, the sharpness analysis unit In 54, before performing the calculation described later, a process of performing gray scale conversion on the color imaging data is performed.

  In the sharpness analysis unit 54, non-patent document 1 (Fumihiko Saito, “Density gradient histogram”) shows an image (hereinafter referred to as “captured image”) indicated by grayscale image data input from the scanner 7 and the line sensor 41. , "Contrast improvement of image by", Denki Theory C, 2006, Vol. 126, No. 2, p.228-236). An evaluation value relating to sharpness (sharpness) is obtained using the method described in H.235.

  Specifically, first, assuming that the value of each pixel of the captured image represented by 256 gradations from 0 to 255 is g (x, y), the density difference (pixel value of the pixel value) from eight neighboring pixels in each pixel. An average value H (x, y) of absolute values of (difference) is obtained by Equation 1.

Subsequently, a value H (x, y) for each pixel is expressed as an integer n by rounding off, for example, and a cumulative histogram indicating n on the horizontal axis and the number of pixels on the vertical axis is generated as a delta histogram. Further, an averaged image obtained by applying a Gaussian filter to the captured image is generated, and a delta histogram is similarly obtained in the averaged image. Then, let D _o (n) be the number of pixels at the value n of the delta histogram directly obtained from the captured image (that is, the delta histogram obtained without applying a Gaussian filter to the captured image), the number of pixels in the value n and D _{b (n),} the number of pixels captured image (or the averaged image) as n _P, evaluation value SF regarding the sharpness of the captured image is determined by the number 2.

  In the sharpness analysis unit 54, the evaluation value of the captured image acquired by the scanner 7 (that is, the evaluation value of the test print image in the offset printing machine 2) and the evaluation value of the captured image acquired by the line sensor 41. That is, a difference (hereinafter referred to as a “sharpness evaluation difference value”) with respect to (an evaluation value of a test print image in the inkjet printer 4) is obtained (step S13). The sharpness evaluation difference value indicates the difference in sharpness between the test print image formed on the print paper by the offset printer 2 and the test print image formed on the print paper by the ink jet printer 4. The processing is processing for acquiring a difference in sharpness between two test print images. Of course, the difference in sharpness between the two test print images may be quantified by a method other than the above method using a delta histogram.

  FIG. A and FIG. B is a diagram illustrating an example of a sharpness filter. FIG. A and FIG. As illustrated in B, the filter information 551 stored in advance in the storage unit 55 of the processing unit 5 indicates a plurality of sharpness filters having different degrees of sharpness processing for enhancing the sharpness of an image. The sharpness filter coefficients (element values) are shown in FIG. A and FIG. As shown in B, it is usually an integer, but may be a decimal.

  The filter information 551 includes a sharpness difference (that is, a sharpness evaluation difference value) between two test print images respectively corresponding to the offset printing machine 2 and the inkjet printer 4, and a test in the inkjet printer 4 among a plurality of sharpness filters. Also shown is a correspondence with a sharpness filter that approximates the sharpness of the print image formed by the inkjet printer 4 to the sharpness of the test print image in the offset printing machine 2 by using the image.

  The sharpness analysis unit 54 specifies and specifies one sharpness filter (hereinafter referred to as “specific sharpness filter”) by referring to the filter information 551 using the sharpness evaluation difference value acquired in the process of step S13. The sharpness filter is input to the sharpness processing unit 56 (step S14).

  Subsequently, in the printed material creation system 1, first image data 61 indicating the first image to be printed on the offset printing machine 2 in the printed material to be created is input from the image storage unit 6 to the image data buffer 311 of the plate making apparatus 3. In the same manner as in the case of the test image data 63, drawing data is generated by the comparison calculation unit 313, and a printing plate showing the first image is produced. Then, by performing printing using the printing plate in the offset printer 2, a first print image 81 is formed on the printing surface 91 of the printing paper 9 as shown in FIG. 5 (step S15).

  When the first image is printed by the offset printing machine 2, the printing paper 9 is conveyed to the inkjet printer 4. Further, the second image data 62 indicating the second image to be printed by the inkjet printer 4 in the printed material to be created is input from the image storage unit 6 to the image data buffer 51 of the processing unit 5. In the sharpness processing unit 56, the value of each pixel of the second image is converted using a specific sharpness filter, and the converted pixel value is input to the comparison calculation unit 53 (step S16). Similarly to the case of the test image data 63, the converted pixel value is compared with the corresponding threshold value of each threshold value matrix to generate drawing data indicating a quaternary halftone image. 4, by controlling the ejection of ink from the head according to the drawing data, a second print image 82 is formed on the print surface 91 of the print paper 9 along with the first print image 81 as shown in FIG. Step S17). Thereby, the printed matter on which the first image and the second image are printed on the same printing surface 91 is created.

  By the way, in the present embodiment, conversion of the value of each pixel of the second image in the sharpness processing unit 56 (step S16), generation of drawing data from the converted pixel value in the comparison calculation unit 53, and Although the printing operation based on the drawing data in the inkjet printer 4 (step S17) is performed in parallel, the above-described step S16 is substantially processed by applying sharpness processing to the second image using a specific sharpness filter. Step S17 is a process for forming the second print image 82 on the printing surface 91 of the printing paper 9 by performing printing in accordance with the processed second image data in the inkjet printer 4.

  In the printed material creation system 1, the processes in steps S15 to S17 are repeated for a large number of printing papers to create a large number of printed materials (step S18). At this time, the offset printing machine 2 prints the same image on a large number of printing papers, and the inkjet printer 4 uses the second image data that is different (or different for each of a plurality of printing papers) for many printing papers ( However, in FIG. 1, only one second image data 62 is shown.) Individual images are printed, and a large number of printed materials including regions indicating different images are efficiently created. When the required number of printed materials is created, the processing for creating the printed material is completed (step S18). In the printed material creation system 1, only the process of step S15 is repeated, so that the same image is printed on a large number of printing sheets by the offset printer 2, and then the processes of steps S16 and S17 are repeated, whereby the inkjet printer 4 Different images may be sequentially printed on these printing sheets.

  As described above, in the printed matter creation system 1, after the first image is printed on the printing paper 9 by the offset printer 2, the processing is performed when the second image is printed on the printing paper 9 by the inkjet printer 4. A processed second image is generated by performing sharpness processing for increasing the sharpness of the second image in the unit 5, and printing is performed by the inkjet printer 4 in accordance with the processed second image data. As a result, a second print image whose sharpness approximates that of the first print image is formed on the printing paper 9 as compared with the print image when the sharpness process is not performed on the second image. Thus, in the printed material creation system 1, the overall texture of the printed material created by so-called hybrid printing is obtained by approximating the sharpness of two printed images formed on the same printing surface by two different printing apparatuses. Can improve the uniformity.

  In the printed material creation system 1, the offset printing machine 2 and the inkjet printer 4 each perform printing using a printing plate showing a test image as test printing, or printing according to test image data, thereby performing offset. Two test print images respectively corresponding to the printer 2 and the ink jet printer 4 are formed on different printing papers, and each of the two test print images is imaged to obtain a difference in sharpness between the two test print images. Then, the sharpness filter to be used is easily specified as the specific sharpness filter by referring to the filter information 551 using the difference in sharpness, and the second image is sharpened using the specific sharpness filter. In this way, by applying the sharpness process to the second image based on the difference in sharpness between the two test print images, the sharpness of the two print images formed on the same print surface can be approximated with high accuracy. Note that the test printing may be performed only when various settings related to printing in the offset printing machine 2 and the inkjet printer 4, the type of ink used for printing, the type of printing paper, or the like is changed. Good.

  FIG. 7 is a block diagram showing a configuration of another example of the printed material creation system. In the printed material creation system 1a of FIG. 7, the offset printing machine 2 and the inkjet printer 4 of FIG. 1 are configured as one printing system 10, and the scanner 7 is not provided. Other configurations are the same as those in FIG. In FIG. 7, the illustration of the image storage unit 6 of FIG. 1 is omitted.

  The printing system 10 is actually an offset printer 2 in which the head of the inkjet printer 4 and the line sensor 41 are arranged on the downstream side of the rotating drum and the intermediate transfer body (that is, the discharge side of the printing paper). Yes, it can be considered that the head of the inkjet printer 4 and the line sensor 41 are provided in the offset printing machine 2. The printing paper on which the image is printed by the offset printing machine 2 passes under the head of the ink jet printer 4 to be printed, and the line sensor 41 can capture the printing image on the printing paper as necessary. It has become.

  When a printed material is created by the printed material creation system 1a of FIG. 7, a test image is printed on a printing paper by the offset printing machine 2, and a similar test image is printed by the inkjet printer 4 on the same printing surface ( FIG. 2: Step S11). Two test print images formed by the offset printer 2 and the ink jet printer 4 are picked up by the line sensor 41, and the picked-up data is input to the sharpness analysis unit 54 (step S12).

  When the image data of the test print image is acquired, the sharpness evaluation difference value is obtained in the same manner as the above process (step S13), and one sharpness filter is specified as the specific sharpness filter by referring to the filter information 551. Is input to the sharpness processing unit 56 (step S14). Subsequently, the plate making apparatus 3 produces a printing plate showing the first image based on the first image data, and the offset printing machine 2 prints the first image on the printing paper by printing using the printing plate. (Step S15). In the sharpness processing unit 56, a processed second image is generated by performing sharpness processing on the second image (step S16). In the inkjet printer 4, the print paper immediately after being discharged from the offset printing machine 2 is generated. Thus, the second image is printed by printing according to the processed second image data (step S17). The processes in steps S15 to S17 are repeated for a large number of printing sheets while changing the second image, and a large number of printed materials are created (step S18).

  As described above, in the printed material creation system 1a of FIG. 7, the offset printing machine 2 and the inkjet printer 4 are arranged along the conveyance path of the printing paper, and the line sensor 41 that is an imaging unit includes the conveyance path. Are disposed downstream of the offset printing machine 2 and the inkjet printer 4. Thereby, in the printed matter creation system 1a, imaging data can be acquired by the same imaging unit, and variations in the quality of captured images that occur when imaging data is acquired by different imaging units can be suppressed. A difference in sharpness between two test print images formed by two different printing apparatuses can be obtained with high accuracy. As a result, it is possible to improve the uniformity of the overall texture of the printed matter created by so-called hybrid printing. In addition, in the printed material creation system 1a, by providing only one line sensor 41, the configuration of the printed material creation system 1a can be simplified.

  FIG. 8 is a block diagram illustrating the configuration of another example of the processing unit. The processing unit 5 a in FIG. 8 is obtained by adding a filter information correction unit 57 to the processing unit 5 in FIG. 1, and the filter information correction unit 57 is connected to the sharpness analysis unit 54 and the storage unit 55. Other configurations are the same as those in FIG. 1, and are denoted by the same reference numerals.

  FIG. 9 is a diagram showing a part of a process flow in which the printed material creation system 1 having the processing unit 5a creates a printed material, and shows a process performed between step S14 and step S15 in FIG. Yes.

  In the printed material creation system 1, when preparing the specific sharpness filter, a test image is printed by each of the offset printer 2 and the inkjet printer 4 (FIG. 2: step S11), and a test print image is captured (step S12). ). Subsequently, in the sharpness analysis unit 54, the evaluation value of the test print image in the offset printer 2 and the evaluation value of the test print image in the inkjet printer 4 are obtained, and the sharpness evaluation difference value is obtained (step S13). Then, by referring to the filter information 551, for example, FIG. The specific sharpness filter shown in A is specified and input to the sharpness processing unit 56 (step S14).

  Subsequently, in the processing unit 5a, FIG. A processed test image is generated by performing sharpness processing on the test image using the specific sharpness filter A (FIG. 9: Step S21), and data of the test image processed by the inkjet printer 4 (see FIG. 1). By performing printing according to the above, a processed test print image is formed on the printing paper (step S22). The processed test print image is captured by the line sensor 41 (step S23), and an evaluation value related to sharpness (that is, an evaluation value of the processed test print image in the ink jet printer 4) is obtained from the captured image indicated by the captured image data (step S23). S24). Then, the sharpness evaluation which is the difference between the evaluation value of the test print image in the offset printing machine 2 obtained in the process of step S13 and the evaluation value of the processed test print image obtained in the process of step S24. A difference value is obtained (step S25).

  When it is confirmed that the sharpness evaluation difference value is not less than or equal to the predetermined value in the filter information correction unit 57 (step S26), FIG. By changing the size and coefficient (element value) of the specific sharpness filter of A, a new sharpness filter is generated and input to the sharpness processing unit 56 (step S27). Subsequently, a new processed test image is generated by performing sharpness processing on the test image using the sharpness filter (step S21), and printing is performed according to the data of the processed test image by the inkjet printer 4. Thus, a processed test print image is formed on the printing paper (step S22). The processed test print image is captured by the line sensor 41 (step S23), and the evaluation value of the processed test print image is obtained (step S24). Then, a sharpness evaluation difference value that is a difference between the evaluation value of the test print image and the evaluation value of the processed test print image in the offset printing machine 2 is obtained (step S25), and the sharpness evaluation difference value becomes equal to or less than a predetermined value. It is confirmed whether or not.

  In this way, in the printed matter creation system 1, the steps S27 and S21 to S25 are performed until a sharpness filter whose sharpness evaluation difference value is equal to or smaller than a predetermined value (hereinafter referred to as “optimized sharpness filter”) is acquired. The process is repeated (step S26), for example, FIG. B sharpness filter is obtained as an optimized sharpness filter. Note that the filter information 551 may be updated so that the optimized sharpness filter corresponds to the sharpness evaluation difference value acquired in step S13.

  Subsequently, the plate making apparatus 3 produces a printing plate showing the first image based on the first image data, and the offset printing machine 2 prints the first image on the printing paper by printing using the printing plate. (FIG. 2: Step S15). Further, the sharpness processing unit 56 generates a processed second image by performing sharpness processing on the second image using the optimized sharpness filter (step S16), and the inkjet printer 4 performs processing of the processed second image. By performing printing according to the data, the second image is printed and the printed matter is completed (step S17). The processes in steps S15 to S17 are repeated for a large number of printing sheets while changing the second image, and a large number of printed materials are created (step S18).

  As described above, in the printed material creation system 1 having the processing unit 5a of FIG. 8, the sharpness evaluation difference value between the test print image in the offset printing machine 2 and the processed test print image in the inkjet printer 4 is predetermined. By correcting the size and coefficient of the sharpness filter so that the value is less than or equal to the value, the sharpness of the two printed images formed on the same printing surface by two different printing apparatuses can be approximated more accurately, and the printed matter The uniformity of texture can be further improved. In the above method, a method for searching for an optimal solution while changing parameters such as size and coefficient little by little (so-called greedy method) is used. Even if an optimized sharpness filter is acquired by another optimization method, Good. Further, the processing unit 5a of FIG. 8 may be provided in the printed material creation system 1a of FIG.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made.

  In the printed material creation systems 1 and 1a, an offset printing machine 2 that is a plate printing apparatus and an inkjet printer 4 that is a plateless printing apparatus are provided, and the offset printing machine 2 uses a printing plate that displays a first image. By performing printing and printing according to the data of the second image processed by the inkjet printer 4, it is possible to improve the uniformity of the texture of the printed material. However, in the printed material creation system, the offset printer 2 and the inkjet In addition to the printer 4, other types of plate printing apparatuses that perform screen printing, gravure printing, flexographic printing, letter press printing, and the like, and other types of plateless printing apparatuses such as an electrophotographic system may be provided. In the printed material creation system, for example, two inkjet printers having different recording resolutions and types of ink are provided, and the processing unit performs sharpness processing on an image to be printed in one inkjet printer, whereby two different inkjet printers are provided. It is also possible to improve the uniformity of the texture of the printed matter created using the printer. As described above, in the printed material creation system, two plate printing apparatuses or two plateless printing apparatuses may be provided.

  As described above, when creating a printed material by printing the first image and the second image on the same printing surface with two different printing apparatuses, in terms of improving the uniformity of the texture of the printed material, In this printing apparatus, printing is performed using the printing plate showing the first image, or printing is performed according to the data of the first image, whereby the first print image is formed on the printing surface of the printing paper, and the second image is formed. A processed second image is generated by performing sharpness processing on the image, and printing is performed using a printing plate indicating the processed second image in the other printing apparatus, or printing is performed according to data of the processed second image. By doing so, a print image when the sharpness process is not performed on the second image (that is, when printing is performed using a printing plate showing the second image, or when printing is performed according to the data of the second image) Sharpness than printing image) to be formed on the printing surface of the second print image for approximating the first print image is important.

  By the way, in the inkjet printing apparatus, the sharpness in the printed image is greatly reduced as compared with other types of plateless printing apparatuses such as an electrophotographic printing apparatus, and the sharpness difference from the printed image in the plate printing apparatus is large. Becomes prominent. Therefore, a technique for performing a sharpness process for increasing sharpness on an image to be printed in the one printing apparatus so that the sharpness of the printed image in one printing apparatus approximates the printed image in the other printing apparatus is It is particularly preferable to employ when the printing apparatus is an ink jet printing apparatus and the other printing apparatus is a plate printing apparatus.

  Further, depending on the use of the printed matter to be created, printing is performed in accordance with image data that is not subjected to sharpness processing in the inkjet printer 4, and processing for reducing sharpness is performed on the image to be printed in the offset printing machine 2. It is also possible to approximate the sharpness of the two print images by acquiring and printing using a printing plate showing the processed image in the offset printing machine 2. That is, in the printed material creation system, the sharpness change process is performed on the image to be printed in one printing apparatus, so that the sharpness is changed to the print image in the other printing apparatus when the sharpness change process is not performed on the image. It is important to form an approximate print image in the one printing apparatus. Note that the image to be printed in the other printing apparatus may be one in which the sharpness is changed from the original image. In this case, the sharpness of the print image in the one printing apparatus is also the other printing apparatus. The sharpness changing process is performed on the image to be printed in the one printing apparatus so as to approximate the sharpness of the printed image.

  In the above-described embodiment, two different printing apparatuses are provided in the printed material creation system. However, in the printed material creation system in which three or more different printing devices are provided, other printing devices are provided in accordance with the sharpness of the printed image in one printing device. Sharpness change processing may be performed on an image to be printed in each printing apparatus.

  The processing flow shown in FIG. 2 may be appropriately changed within a possible range. For example, depending on the type of printing apparatus provided in the printed material creation system, after the process of generating the processed second image (step S16) and the process of forming the second print image on the print surface (step S17), the second A process of forming one print image on the print surface (step S15) may be performed.

  The print medium in the printed material creation systems 1 and 1a may be a film, a plate-like member, or the like in addition to the printing paper.

It is a block diagram which shows the structure of a printed matter production system. It is a figure which shows the flow of the process which produces printed matter. It is a figure which shows a test image. It is a figure which shows a sharpness filter. It is a figure which shows a sharpness filter. It is a figure which shows the printing paper in which the 1st print image was formed. It is a figure which shows the printing paper in which the 1st and 2nd printing image was formed. It is a block diagram which shows the structure of the other example of a printed matter production system. It is a block diagram which shows the structure of the other example of a process part. It is a figure which shows a part of flow of the process which produces printed matter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1a Print production system 2 Offset printer 4 Inkjet printer 5,5a Processing part 7 Scanner 9 Printing paper 41 Line sensor 55 Memory | storage part 61 1st image data 62 2nd image data 63 Test image data 81 1st print image 82 1st Two print images 91 Print surface 551 Filter information S11-S13, S15-S17 Steps

Claims (10)

A printed matter creation method for creating a printed matter in which a first image and a second image are printed on the same printing surface,
a) In the printing apparatus, printing using a printing plate showing the first image, or printing according to the data of the first image to form the first print image on the printing surface of the print medium; ,
b) generating a processed second image by subjecting the second image to a sharpness change process;
c) In another printing apparatus different from the printing apparatus, printing is performed using a printing plate showing the processed second image, or printing is performed according to the data of the processed second image, Forming a second print image on the print surface, the sharpness of which is closer to the first print image than the print image when the sharpness changing process is not performed on the second image;
A printed matter creating method comprising: The printed matter creation method according to claim 1,
d) In each of the printing apparatus and the other printing apparatus, printing is performed using a printing plate showing a predetermined test image, or printing is performed in accordance with the data of the test image, whereby the printing apparatus and the printing apparatus Forming two test print images respectively corresponding to another printing apparatus on the same or different print media;
e) capturing each of the two test print images to obtain a sharpness difference between the two test print images;
Further comprising
In the step b), the sharpness changing process is performed on the second image based on a difference in sharpness between the two test print images. The printed matter creation method according to claim 2,
Filter information indicating a correspondence between a plurality of filters and a difference in sharpness between two test print images respectively corresponding to the printing apparatus and the other printing apparatus is prepared,
A filter is identified by referring to the filter information using a difference in sharpness between the two test print images acquired in the step e), and in the step b), the first filter is used by using the filter. A printed matter creating method, wherein the sharpness changing process is performed on two images. A printed matter creation method according to any one of claims 1 to 3,
The printing device is a plate printing device that performs printing using a printing plate showing the first image;
The printed material creation method, wherein the another printing device is a plateless printing device that performs printing according to the data of the processed second image. The printed matter creation method according to claim 4,
The another printing apparatus is an inkjet printing apparatus;
In the step b), the processed second image is generated by performing the sharpness changing process for increasing the sharpness of the second image. A printed matter creation system for creating a printed matter in which a first image and a second image are printed on the same printing surface,
A printing apparatus that forms a first print image on a printing surface of a print medium by printing using a printing plate showing a first image, or by printing according to the data of the first image;
A processing unit that generates a processed second image by performing a sharpness change process on the second image;
A print image when the sharpness changing process is not performed on the second image by performing printing using a printing plate representing the processed second image or by performing printing according to the data of the processed second image Another printing device that forms a second printed image on the printed surface, the sharpness of which is closer to the first printed image than the first printed image;
A printed matter creating system comprising: The printed matter creation system according to claim 6,
In each of the printing apparatus and the other printing apparatus, printing is performed using a printing plate showing a predetermined test image as test printing, or printing is performed according to the data of the test image, thereby the printing apparatus and Two test print images respectively corresponding to the another printing apparatus are formed on the same or different print media, and by imaging each of the two test print images, a difference in sharpness between the two test print images can be obtained. Acquired, and the processing unit performs the sharpness changing process on the second image based on a difference in sharpness between the two test print images. The printed matter creation system according to claim 7,
A storage unit for storing filter information indicating a correspondence between a plurality of filters and a difference in sharpness between two test print images respectively corresponding to the printing apparatus and the other printing apparatus;
The processing unit identifies one filter by referring to the filter information using a difference in sharpness between the two test print images acquired by the test printing, and uses the filter to identify the second image. The printed matter creating system, wherein the sharpness changing process is performed on the printed matter. A printed matter creation system according to claim 7 or 8,
An imaging unit that captures the two test print images acquired by the test printing;
The printing apparatus and the another printing apparatus are arranged along a conveyance path of a printing medium, and the imaging unit is arranged on the downstream side of the printing apparatus and the other printing apparatus in the conveyance path. A printed material creation system.   A printed matter formed by the printed matter producing method according to claim 1.

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