Printing device and printing method

Abstract

To reduce burden on a user that is required for performing printing on a medium that may include distortion and improve the quality of a printed matter.SOLUTION: A printing device identifies, as preparation processing, a first feature color and a second feature color from first captured image data for a medium; generates binary image data constituted of a first color and a second color by binarizing first pattern image data having information on pattern shapes of the medium; generates second pattern image data by replacing the first color of the binary image data by the first feature color and replacing the second color by the second feature color; sets feature points for an edge of the pattern in the second pattern image data; calculates a correction value for the feature points that is necessary for matching the shape of the pattern in the second pattern image data with the shape of the pattern in the second photographed image data, on the basis of collation of the second photographed image data for the medium with the second pattern image data, as a printed matter producing process; and applies the correction value to a colored image of the pattern to deform the image and executes printing of the deformed colored image on the medium captured in order to generate the second photographed image data.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a printing apparatus and a printing method. [Background technology]

[0002] 2. Description of the Related Art There is known an inkjet printer that prints on a medium using a head having nozzles capable of ejecting droplets, and that has an imaging device as a surface information acquisition device that acquires information about the surface of the medium (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-63795 A Summary of the Invention [Problem to be solved by the invention]

[0004] Here, it is assumed that a fabric on which a pattern is formed is used as a medium, and printing is performed on the transported fabric. In many cases, a pattern is periodically formed on the fabric. A user prepares a coloring image to be used to color the pattern on the fabric. The fabric may be distorted or expanded / contracted (hereinafter collectively referred to as "distortion") during transportation. Even if a coloring image is printed by overlaying it on the pattern of such distorted fabric, a misalignment occurs between the shape of the pattern and the colored pixels. For this reason, a user needs to perform an editing operation using image editing software to match the shape of the coloring image to the shape of the pattern in the captured image of the transported fabric.

[0005] However, the above-mentioned editing work places a great burden on the user. In view of this situation, there is a need for an improvement to reduce the burden on the user when printing on a medium that may contain distortion and to improve the quality of the printed matter. [Means for solving the problem]

[0006] The printing device includes a transport unit that transports a medium on which a pattern is formed in a transport direction, an imaging unit that images the medium transported by the transport unit, a printing unit that prints on the medium transported by the transport unit, and a control unit, and the control unit, as a preparatory process for a print production process including printing by the printing unit, acquires first pattern image data having information on a shape of the pattern and first captured image data generated by imaging the medium by the imaging unit, identifies a first characteristic color and a second characteristic color brighter than the first characteristic color from the first captured image data, binarizes the first pattern image data to generate binary image data of the first color and the second color brighter than the first color, replaces the first color of the binary image data with the first characteristic color and a second pattern image data is generated by replacing two colors with the second characteristic color, feature points are set for edges of a pattern in the second pattern image data, and as the print production process, second captured image data generated by imaging the medium with the imaging unit is obtained, and based on a comparison between the second captured image data and the second pattern image data, a correction value for the feature point required to match a shape of the pattern in the second pattern image data to a shape of the pattern in the second captured image data is calculated, the correction value is applied to a colored image for coloring the pattern to deform the colored image, and the printing unit is caused to print the deformed colored image on the medium imaged by the imaging unit to generate the second captured image data.

[0007] The printing method includes an imaging step of imaging a medium on which a pattern is formed and which is transported in a transport direction, a print production step including printing on the medium transported in the transport direction, and a preparation step for the print production step, in which the preparation step includes acquiring first pattern image data having information on a shape of the pattern and first captured image data generated by imaging the medium in the first imaging step, identifying a first characteristic color and a second characteristic color brighter than the first characteristic color from the first captured image data, binarizing the first pattern image data to generate binary image data of the first color and a second color brighter than the first color, replacing the first color of the binary image data with the first characteristic color and replacing the second color with the first characteristic color. with the second characteristic color to generate second pattern image data, and set feature points for edges of the pattern in the second pattern image data; in the print production process, second captured image data generated by imaging the medium in the second imaging process is acquired, and based on a comparison between the second captured image data and the second pattern image data, a correction value for the feature point required to match a shape of the pattern in the second pattern image data to a shape of the pattern in the second captured image data is calculated, the correction value is applied to a colored image for coloring the pattern to deform the colored image, and the deformed colored image is printed on the medium imaged in the second imaging process. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram showing a simplified configuration of a printing apparatus. [Diagram 2] FIG. 2A is a diagram showing the transported fabric and the configuration in the vicinity thereof as viewed from above, and FIG. 2B is a diagram showing a part of the configuration shown in FIG. 2A as viewed from upstream. [Diagram 3] 4 is a flowchart showing a printing process. [Figure 4] FIG. 4A is a diagram showing an example of first pattern image data, and FIG. 4B is a diagram showing an example of first captured image data. [Diagram 5] FIG. 4 is a diagram illustrating an example of a histogram of the first captured image data. [Figure 6]FIG. 6A is a diagram showing an example of binary image data, FIG. 6B is a diagram showing an example of second pattern image data, and FIG. 6C is a diagram showing an example of a state in which feature points are set in the second pattern image data. [Figure 7] FIG. 11 is a diagram for explaining step S170. [Figure 8] FIG. 11 is a diagram for explaining a specific example of steps S170 and S180. [Figure 9] FIG. 11 is a diagram for explaining a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that each drawing is merely an example for explaining the present embodiment. Since each drawing is an example, the ratio, shape, and shading may not be accurate, may not match each other, and some parts may be omitted.

[0010] 1.Device configuration: 1 shows a simplified configuration of a printing device 10 according to this embodiment. The printing device 10 executes a printing method. The printing device 10 includes a control unit 11, a display unit 13, an operation reception unit 14, an imaging unit 15, a transport unit 16, a printing unit 17, a storage unit 18, a communication IF 19, and the like. IF stands for interface. The control unit 11 includes one or more ICs having a CPU 11a, ROM 11b, RAM 11c, and the like as a processor, and other non-volatile memories, and the like.

[0011] In the control unit 11, a processor, i.e., a CPU 11a, executes arithmetic processing according to one or more programs 12 stored in a ROM 11b or other memory, using a RAM 11c or the like as a work area, thereby controlling the printing device 10. Note that the processor is not limited to a single CPU, and may be configured to perform processing using multiple CPUs or a hardware circuit such as an ASIC, or may be configured to perform processing in cooperation with a CPU and a hardware circuit.

[0012] The display unit 13 is a means for displaying visual information, and is configured, for example, by a liquid crystal display, an organic electroluminescence display, or the like. The display unit 13 may be configured to include a display and a drive circuit for driving the display. The operation reception unit 14 is a means for receiving operations by a user, and is realized, for example, by a physical button, a touch panel, a mouse, a keyboard, or the like. Of course, the touch panel may be realized as one function of the display unit 13. The display unit 13 and the operation reception unit 14 may be part of the configuration of the printing device 10, or may be peripheral devices external to the printing device 10.

[0013] The storage unit 18 is, for example, a hard disk drive, a solid state drive, or other memory-based storage means. A part of the memory of the control unit 11 may be regarded as the storage unit 18. The storage unit 18 may be regarded as a part of the control unit 11.

[0014] The communication IF 19 is a general term for one or more IFs that allow the printing device 10 to communicate with an external device (not shown) via wired or wireless communication in compliance with a predetermined communication protocol including a known communication standard. Examples of the external device include a personal computer (PC), a server, a smartphone, a tablet terminal, a scanner, etc.

[0015] The conveying unit 16 is a mechanism for conveying the medium in a predetermined conveying direction under the control of the control unit 11. In this embodiment, the medium is mainly assumed to be a fabric on which a three-dimensional pattern is formed by devising a weaving method of threads or fibers, such as a jacquard woven fabric or a lace fabric. Some pattern or a group of patterns are formed in a repeated line on the fabric. In the following, one or a group of patterns will be treated as one pattern. However, the medium may be a material other than fabric as long as it is a material that may be distorted during conveyance, such as paper on which a pattern is formed.

[0016] Conveying unit 16 includes, for example, a pay-out roller that pays out the unprinted fabric wound in a roll downstream in the conveyance direction, a belt and rollers for further conveying the paid-out fabric, a take-up roller that re-winds the fabric after printing into a roll and collects it, a motor for rotating each roller and belt, etc. Hereinafter, the upstream and downstream of the conveying direction by conveying unit 16 will also be simply referred to as upstream and downstream.

[0017] The imaging unit 15 captures an image of the medium transported by the transport unit 16 under the control of the control unit 11. The imaging unit 15 includes a light source that illuminates the medium, an image sensor that receives reflected light from the medium and outputs an electrical signal as the imaging result, and a circuit that generates captured image data by performing analog-to-digital conversion or the like on the output electrical signal. A part of the circuitry of the control unit 11 may be regarded as a part of the imaging unit 15.

[0018] The printing unit 17 prints on the medium transported by the transport unit 16 under the control of the control unit 11. The printing unit 17 is provided downstream of the imaging unit 15. The printing unit 17 prints on the medium based on print data transmitted from the control unit 11. The printing unit 17 can perform printing by ejecting ink of multiple colors such as cyan, magenta, yellow, and black using an inkjet method. According to the inkjet method, the printing unit 17 prints on the medium by ejecting or not ejecting dots of ink from nozzles (not shown) based on print data that specifies dot-on or dot-off of each ink for each pixel.

[0019] The printing device 10 may be a single printer, or may be realized by multiple devices connected to each other so that they can communicate with each other. The printing device 10 configured by multiple devices may be called a printing system 10. The printing system 10 is configured to include, for example, a printer including an imaging unit 15, a transport unit 16, and a printing unit 17, and one or more information processing devices functioning as a control unit 11. The information processing device is, for example, a PC, a server, a smartphone, a tablet terminal, or a device having a processing capability equivalent thereto. In the printing system 10, a device that serves as the control unit 11 may be called an image processing device, a print control device, or the like. It is also possible to regard some of the devices that configure the printing system 10 as inventions.

[0020] Fig. 2A shows the fabric 30 as a transported medium and its surrounding structure from a perspective looking downward. In Fig. 2A, the pattern formed in advance on the fabric 30 is not shown. The direction in which the fabric 30 is transported by the transport unit 16 is indicated by the symbol D1. The symbol 23 indicates an endless belt 23 that is a part of the transport unit 16. The fabric 30 placed on the endless belt 23 is transported from upstream to downstream as the endless belt 23 rotates.

[0021] A carriage 20 is disposed above the endless belt 23. The carriage 20 is capable of reciprocating movement along a direction D2 that intersects with the conveying direction D1. Here, "intersect" means "orthogonal," but it may be understood that "orthogonal" does not only mean strictly orthogonal, but also includes errors that occur during the manufacturing process of the product. The carriage 20 moves along a long guide member 21 in the direction D2. The direction D2 is also referred to as the main scanning direction of the carriage 20 and the print head 22. The direction D2 is also referred to as the width direction of the fabric 30.

[0022] The carriage 20 is equipped with a print head 22 capable of ejecting ink. In other words, the print head 22 moves back and forth together with the carriage 20 in the width direction D2. Such carriage 20 and print head 22 constitute the printing unit 17. Although not shown, the print head 22 has a plurality of nozzles opened on its lower surface facing the endless belt 23. While moving together with the carriage 20 in the width direction D2, the print head 22 ejects ink from the nozzles based on print data.

[0023] As shown in FIG. 2A, the imaging unit 15 is disposed at a predetermined position above the endless belt 23 and upstream of the carriage 20 and the print head 22. FIG. 2B shows a part of the configuration shown in FIG. 2A from a viewpoint facing from upstream to downstream. The imaging unit 15 has an imaging surface 15a on the lower surface facing the endless belt 23, and images the fabric 30 on the endless belt 23 through the imaging surface 15a. The imaging unit 15 is, for example, a line-scan type camera in which multiple imaging elements are arranged along the width direction D2 inside. The imaging unit 15 repeats imaging on a line-by-line basis through a lens and imaging elements (not shown) provided on the imaging surface 15a. In FIG. 2B, the imaging range of the imaging unit 15 in the width direction D2 is illustrated by a dashed line. The imaging unit 15 is capable of imaging almost the entire range of the endless belt 23 in the width direction D2 by the function of the lens.

[0024] The configuration of the imaging unit 15 is not limited to the example of FIGS. 2A and 2B. For example, a configuration may be adopted in which a plurality of imaging units 15 are arranged along the width direction D2 above the endless belt 23, and each of the plurality of imaging units 15 is responsible for imaging a portion of the entire range of the endless belt 23 in the width direction D2. Alternatively, the imaging unit 15 may be a line sensor configured by arranging a plurality of imaging elements over almost the entire range of the endless belt 23 in the width direction D2. Alternatively, the imaging unit 15 may be mounted on a carriage that is movable along the width direction D2, similar to the print head 22 being mounted on the carriage 20, and may be configured to image the endless belt 23 while moving in the width direction D2 by the carriage. In addition, the print head 22 may not be configured to move along the width direction D2 by the carriage 20, but may be a so-called line head having a size capable of ejecting ink over almost the entire range of the endless belt 23 in the width direction D2 in a stationary state.

[0025] 2.Printing method: 3 is a flowchart showing the printing process executed by the control unit 11 in accordance with the program 12. The flowchart is generally made up of a print production process S2 and a preparation process S1 for the print production process S2. The preparation process S1 is also called a preparation step, and the print production process S2 is also called a print production step. In FIG. 3, the preparation process S1 and the print production process S2 are consecutively described in one flowchart, but there may be a time gap between the preparation process S1 and the print production process S2, and the print production process S2 can be repeatedly executed any number of times after the preparation process S1.

[0026] In step S100, the control unit 11 acquires pattern image data having information on the shape of the pattern on the fabric 30. The pattern image data acquired in step S100 is also called "first pattern image data." The first pattern image data may have information on the shape of the pattern in any manner, whether directly or indirectly. For example, the first pattern image data is image data that expresses the shape of the pattern by color. "Expressing the shape of the pattern by color" means expressing the difference between the presence and absence of a pattern or the difference in the pattern so that it can be seen by the presence or absence of color or the difference in color. Therefore, the color in the first pattern image data has no relation to the color of the print. The color system adopted by the first pattern image data to express the color can be various, such as the RGB color system or the L*a*b* color system. The first pattern image data may be image data in a raster format or vector format. The first pattern image data may also be CAD data.

[0027] In this embodiment, the first pattern image data and "colored image data" described later are data generated in advance. The first pattern image data and colored image data may be generated by any method, but are generally generated by a designer or an engineer. The first pattern image data is, for example, stored in advance in the storage unit 18, and the control unit 11 acquires the first pattern image data from the storage unit 18. Alternatively, the first pattern image data is input from an external device via the communication IF 19, and the control unit 11 acquires the input first pattern image data. The control unit 11 may acquire the first pattern image data from a storage medium such as a memory card (not shown) externally attached to the printing device 10. Step S100 may be executed before step S130 described later.

[0028] FIG. 4A shows an example of the first pattern image data 40. The file format of the first pattern image data 40 is not limited, but for example, the first pattern image data 40 is an image file created by CAD software. According to FIG. 4A, the first pattern image data 40 is expressed by a first region 41 in white, a second region 42 in a predetermined color darker than white, and a third region 43 in another predetermined color darker than the second region 42. That is, in the first pattern image data 40, the second region 42 and the third region 43 express one pattern, and the first region 41 is an area without a pattern, that is, the background. The actual design of the pattern is diverse, and there are naturally more complicated patterns, but here, the pattern is a simple triangle for easy understanding. In FIG. 4A etc., the orthogonal X-axis and Y-axis are two axes for defining the coordinates of the image data, and the Y-axis direction corresponds to the conveying direction D1, and the X-axis direction corresponds to the width direction D2.

[0029] In step S110, the control unit 11 captures an image of the fabric 30. That is, the control unit 11 causes the conveying unit 16 to start conveying the medium 30 and causes the imaging unit 15 to capture an image. As a result of such imaging, captured image data is generated, and the control unit 11 acquires the captured image data. The captured image data is bitmap data having a gradation value for each pixel. The gradation value is expressed in 256 gradations from 0 to 255, for example. The captured image data acquired in step S110 is also called "first captured image data." In step S110, since it is sufficient to be able to capture an image of the pattern of the fabric 30, the conveying unit 16 only needs to convey the fabric 30 to a degree that the fabric 30 passes downstream of the position of the imaging unit 15 by a predetermined distance.

[0030] Fig. 4B shows an example of the first captured image data 50. Since the first captured image data 50 is an image of the fabric 30, Fig. 4B shows only a partial range including one pattern in the first captured image data 50. According to Fig. 4B, the first captured image data 50 is expressed by a fourth region 51, a fifth region 52, and a sixth region 53, each of which is a different color. As can be seen from a comparison with Fig. 4A, in the first captured image data 50, the fifth region 52 and the sixth region 53 express one pattern, and the fourth region 51 is the background of the pattern. The color of the fourth region 51 may be interpreted as the color of the fabric 30 itself.

[0031] 4A, the triangular pattern consisting of the fifth region 52 and the sixth region 53 in the first captured image data 50 is distorted compared to the triangular pattern consisting of the second region 42 and the third region 43 in the first pattern image data 40. This distortion is caused by distortion occurring in the fabric 30 during transportation when the image was captured in step S110. The first pattern image data 40 and the colored image data each represent an ideal pattern without distortion.

[0032] In step S120, the control unit 11 identifies a first characteristic color and a second characteristic color brighter than the first characteristic color from the first captured image data. A characteristic color is a color that is relatively abundant in the image data. Specifically, the control unit 11 generates a histogram of colors in the first captured image data, and identifies the colors corresponding to the peaks of the distribution shown in the histogram as the first characteristic color and the second characteristic color.

[0033] 5 illustrates an example of a histogram of the first captured image data 50. Here, the first captured image data 50 from which the histogram is generated is assumed to be grayscaled image data having a luminance value for each pixel. In other words, the luminance value is regarded as a color. If the first captured image data 50 generated by the imaging unit 15 is color image data having red (R), green (G), and blue (B) gradation values ​​for each pixel, for example, the control unit 11 may convert the RGB values ​​for each pixel of the first captured image data 50 into luminance values, grayscale the data, and then generate a histogram.

[0034] According to FIG. 5, the histogram is a frequency distribution with the horizontal axis representing the gradation value of the luminance value and the vertical axis representing the number of pixels. According to the histogram, peaks of the number of pixels occur at luminance values L1 and L2, respectively. Also, L1 < L2. Therefore, in the example of FIG. 5, the control unit 11 may specify the luminance value L1 as the first characteristic color and the luminance value L2 as the second characteristic color. According to FIGS. 4B and 5, the luminance value L1 corresponds to the peak of the mountain where the luminance values corresponding to the colors of the fifth region 52 and the sixth region 53 corresponding to the pattern are concentrated and distributed. On the other hand, the luminance value L2 corresponds to the peak of the mountain where the luminance values corresponding to the color of the fourth region 51, which is brighter than the fifth region 52 and the sixth region 53, are concentrated and distributed. When three or more peaks occur in the histogram generated from the first captured image data 50, the control unit 11 may select the two higher peaks among them and specify the first characteristic color and the second characteristic color.

[0035] In step S130, the control unit 11 binarizes the first pattern image data to generate "binary image data". First, the control unit 11 grayscales the first pattern image data. The control unit 11 may grayscale the first pattern image data after converting the file format of the first pattern image data to bitmap if necessary. Then, the control unit 11 binarizes each pixel of the first pattern image data into a black pixel with a luminance value = 0 or a white pixel with a luminance value = 255 by comparing the luminance value with a predetermined threshold value to obtain binary image data. The black pixels in the binary image data correspond to the first color, and the white pixels correspond to the second color.

[0036] As shown in FIG. 4A, the first pattern image data 40 is composed of a background by the first region 41 and patterns by the second region 42 and the third region 43, which are darker than the background. Therefore, the threshold value is set to a gradation value such as luminance value = 200 that can separate the background and the pattern. The control unit 11 converts the pixels with luminance values equal to or lower than the threshold value among the pixels of the first pattern image data into black pixels, and converts the pixels with luminance values higher than the threshold value into white pixels.

[0037] Fig. 6A shows an example of binary image data 44 obtained by binarizing the first pattern image data 40 in step S130. As can be seen from a comparison with the first pattern image data 40 in Fig. 4A, in the binary image data 44, the entire pattern is made up of black pixels, and the area other than the pattern is made up of white pixels.

[0038] In step S140, the control unit 11 applies the first and second characteristic colors identified in step S120 to the binary image data generated in step S130. The application here refers to a process of replacing the first color of the binary image data, i.e., black pixels, with the first characteristic color, and the second color of the binary image data, i.e., white pixels, with the second characteristic color. The binary image data after the application of the first and second characteristic colors is called "second pattern image data."

[0039] Fig. 6B illustrates the second pattern image data 45 generated in step S140. In the second pattern image data 45, the pattern area which was black pixels in the binary image data 44 in Fig. 6A has a first characteristic color, and the background area which was white pixels in the binary image data 44 has a second characteristic color. As can be seen from a comparison with Fig. 4B, the second pattern image data 45 has a color tone quite similar to that of the first captured image data 50.

[0040] In step S150, the control unit 11 sets feature points for the edges of the pattern in the second pattern image data. The edges of the pattern are pixels at positions where the second characteristic color switches to the first characteristic color, and therefore can be easily identified. The feature points may be called control points or the like.

[0041] Fig. 6C shows a state in which feature points P1, P2, and P3 are set on the edges of the pattern in the second pattern image data 45. Fig. 6C shows an example in which feature points P1, P2, and P3 are set at the intersections of the edges of the pattern, i.e., at the vertices of a triangle that is the pattern. Of course, there is no limit to the number of feature points that can be set. The control unit 11 stores the second pattern image data with the feature points set in the memory unit 18 so that it can be used at any time thereafter. The above steps S100 to S150 constitute the preparation process S1.

[0042] Next, the print production process S2 including steps S160 to S190 will be described. In step S160, the control unit 11 captures an image of the fabric 30. The description of step S160 basically applies mutatis mutandis to the description of step S110. The fabric 30 captured in step S110 and the fabric 30 captured in step S160 have the same pattern. The captured image data acquired in step S160 is called "second captured image data." In one case, the fabric 30 that has been captured in step S110 and is in a stopped state may be imaged by restarting the conveyance in step S160. In another case, the fabric 30 with the same pattern as the fabric 30 captured in step S110 may be newly set in the conveyance unit 16, and the conveyance may be started in step S160 to capture the image.

[0043] The first captured image data and the second captured image data, which are the results of capturing images of fabric 30 with the same pattern, are naturally almost the same image data, but because the timing of capturing images is different, there may be subtle differences in color between the two, and the presence or absence and degree of distortion of fabric 30 at the time of capturing images may differ. Since the transport of fabric 30 started in step S160 is also a transport for printing in step S190, control unit 11 ends the transport after printing in step S190 is completed.

[0044] In step S170, the control unit 11 calculates correction values ​​for the feature points required to match the shape of the pattern in the second pattern image data to the shape of the pattern in the second captured image data, based on a comparison between the second captured image data and the second pattern image data. 7 illustrates the second pattern image data 45 and the second captured image data 54 to explain step S170. The second captured image data 54 can be viewed in the same way as the first captured image data 50. The control unit 11 sets rectangular regions W1, W2, and W3 that include characteristic points P1, P2, and P3 in the second pattern image data 45 at their approximate centers. Such rectangular regions W1, W2, and W3 are also called ROIs (Regions of Interest), regions of interest, target regions, etc.

[0045] The control unit 11 extracts regions similar to the images of the rectangular regions W1, W2, and W3 from the second captured image data 54 using an image matching technique such as template matching. As a result, a rectangular region W4 is extracted from the second captured image data 54 as a region similar to the rectangular region W1, a rectangular region W5 is extracted from the second captured image data 54 as a region similar to the rectangular region W2, and a rectangular region W6 is extracted from the second captured image data 54 as a region similar to the rectangular region W3. As described above, the color tone of the second pattern image data 45 is close to that of the first captured image data 50, and is therefore also close to that of the second captured image data 54. Therefore, step S170 is a matching operation between images with similar color usage, and the accuracy is improved.

[0046] That is, even if the shape of the pattern in the second captured image data 54 is affected by the distortion of the fabric 30, the areas corresponding to the rectangular areas W1, W2, and W3 including the characteristic points P1, P2, and P3 in the second pattern image data 45 can be extracted with high accuracy from the second captured image data 54. The control unit 11 calculates correction values ​​for the coordinates of the characteristic points P1, P2, and P3 required to match the relative positional relationship of the rectangular areas W1, W2, and W3 in the XY coordinate system with the relative positional relationship of the rectangular areas W4, W5, and W6, for example. The correction values ​​are the amount and direction of movement in the XY coordinate system.

[0047] In step S180, the control unit 11 acquires colored image data representing a colored image for coloring the pattern. That is, the color of the colored image is the color to be printed over the pattern of the fabric 30. The shape of the colored image represented by the colored image data is equal to the shape of the pattern represented by the first pattern image data and the second pattern image data. The colored image data is, for example, stored in advance in the storage unit 18, and the control unit 11 acquires the colored image data from the storage unit 18. Alternatively, the colored image data is input from an external device via the communication IF 19, and the control unit 11 acquires the input colored image data. The control unit 11 may acquire the colored image data from a storage medium such as a memory card (not shown) externally attached to the printing device 10.

[0048] Then, the control unit 11 applies the correction value calculated in step S170 to the colored image of the colored image data to deform the colored image. That is, the control points in the colored image data that correspond to the characteristic points of the second pattern image data are moved by applying the correction value of the characteristic points. The control unit 11 deforms the area surrounded by the multiple control points, i.e., the colored image, in accordance with the movement of each of the multiple control points. The process of deforming an area in accordance with the movement of the control points is well known.

[0049] In step S190, the control unit 11 causes the printing unit 17 to print the colored image after the transformation in step S180 on the fabric 30 being transported by the transport unit 16. The fabric 30 being transported at this point is the medium imaged by the imaging unit 15 to generate the second captured image data. Needless to say, printing the colored image after the transformation is printing based on print data generated from colored image data including the colored image after the transformation. The process in which the control unit 11 generates print data from image data is general image processing such as color conversion processing and halftone processing, and so details will be omitted.

[0050] FIG. 8 is a diagram for explaining a specific example of the print production process S2, particularly steps S170 and S180. FIG. 8 shows the second pattern image data 45 and the second captured image data 54. The second captured image data 54 shown in FIG. 8 is a result of capturing an image of the entire width of the fabric 30 in the width direction D2 and a range of length including one pattern in the conveying direction D1 (hereinafter, a certain range), and multiple patterns are lined up in the width direction D2, i.e., the X-axis direction, in the second captured image data 54. In FIG. 8, the second captured image data 54 is divided into pattern unit areas 54a, 54b, 54c, etc. including one pattern for easy understanding. The broken lines dividing the pattern unit areas 54a, 54b, 54c, etc. do not actually exist. The second captured image data 54 shown in FIG. 7 corresponds to one pattern unit area.

[0051] In step S170, the control unit 11 compares the second pattern image data 45 with each of the pattern unit areas 54a, 54b, 54c... of the second captured image data 54 on a one-to-one basis, and calculates the correction value as described above for each of the pattern unit areas 54a, 54b, 54c.... Since the degree of distortion of the fabric may differ for each of the pattern unit areas 54a, 54b, 54c..., the calculated correction value may also differ for each of the pattern unit areas 54a, 54b, 54c....

[0052] 8 shows a plurality of colored image data 60 corresponding to one pattern arranged side by side. In step S180, the control unit 11 arranges the colored image data 60 along the X-axis direction so as to correspond to each pattern of a certain range of the second captured image data 54, thereby generating a group of the plurality of colored image data 60. Then, the correction value calculated for each pattern unit area 54a, 54b, 54c... is applied to each piece of colored image data 60 in the group of the plurality of colored image data 60 to deform the colored image.

[0053] For example, the control unit 11 applies a correction value calculated from matching the pattern unit area 54a located at the leftmost position in the viewpoint of Fig. 8 with the second pattern image data 45 to the leftmost colored image data 60 in the group of multiple colored image data 60, generating colored image data 61a, which is the colored image data 60 after colored image transformation. Similarly, the control unit 11 applies a correction value calculated from matching the pattern unit area 54b located second from the left in the viewpoint of Fig. 8 with the second pattern image data 45 to the second colored image data 60 from the left in the group of multiple colored image data 60, generating colored image data 61b, which is the colored image data 60 after colored image transformation. Thereafter, the control unit 11 similarly applies a correction value calculated from matching the pattern unit area 54c located third from the left with the second pattern image data 45 to the third colored image data 60 from the left in the group of multiple colored image data 60, generating colored image data 61c, which is the colored image data 60 after colored image transformation.

[0054] In step S190, the control unit 11 prints a set of colored image data for a certain range, in which the colored image data 61a, 61b, 61c, etc. are arranged, on a certain range of the fabric 30 by the printing unit 17. As a result, the colored image is printed in a shape that is not misaligned with the shape of the pattern on the fabric 30 being transported. The transport speed of the medium by the transport unit 16 and the distance from the imaging unit 15 to the print head 22 in the transport direction D1 are known to the control unit 11. Therefore, the control unit 11 executes steps S170 and S180 during the period until the certain range of the fabric 30 captured by the imaging unit 15 in step S160 reaches the position of the print head 22, and executes printing in step S190 at a predetermined timing when the certain range reaches the position of the print head 22. In addition, the control unit 11 repeats the cycle of steps S160 to S190 for the certain range of the fabric 30, thereby making it possible to continuously print on the fabric 30 in which multiple certain ranges are continuous in the transport direction D1.

[0055] 3. Summary: Thus, according to this embodiment, the printing device 10 includes a conveying unit 16 that conveys a medium on which a pattern is formed in a conveying direction D1, an imaging unit 15 that captures an image of the medium conveyed by the conveying unit 16, a printing unit 17 that prints on the medium conveyed by the conveying unit 16, and a control unit 11. As a preparation process S1 for a print production process S2 including printing by the printing unit 17, the control unit 11 acquires first pattern image data having information on the shape of the pattern and first captured image data generated by capturing an image of the medium by the imaging unit 15, identifies a first characteristic color and a second characteristic color brighter than the first characteristic color from the first captured image data, binarizes the first pattern image data to generate binary image data of the first color and a second color brighter than the first color, generates second pattern image data by replacing the first color of the binary image data with the first characteristic color and the second color with the second characteristic color, and sets feature points for edges of the pattern in the second pattern image data. Then, as the print production process S2, second captured image data generated by imaging the medium using the imaging unit 15 is acquired, and based on a comparison between the second captured image data and the second pattern image data, correction values ​​for feature points required to match the shape of the pattern in the second pattern image data to the shape of the pattern in the second captured image data are calculated, the correction values ​​are applied to the colored image for coloring the pattern to deform the colored image, and the printing unit 17 is caused to print the deformed colored image on the medium that was captured by the imaging unit 15 to generate the second captured image data.

[0056] According to the above configuration, the control unit 11 applies the first and second characteristic colors identified from the first captured image data to the binary image data of the first pattern image data to generate the second pattern image data. As a result, the color of the second captured image data and the color of the second pattern image data are similar to each other, so that the accuracy of matching such as template matching between the second captured image data and the second pattern image data is improved, and an appropriate correction value can be obtained. As a result, a colored image accurately deformed by the correction value is printed on the medium, so that even if the medium being conveyed is distorted, a high-quality print result without deviation can be obtained in which the shape of the medium pattern and the colored image match. In addition, according to this embodiment, the user does not need to manually perform an editing operation to match the shape of the colored image to the shape of the pattern in the captured image data of the medium being conveyed, so that a high-quality print result can be obtained with less burden than before.

[0057] Furthermore, according to this embodiment, in the preparation process S1, the control unit 11 generates a histogram of colors in the first captured image data, and identifies the colors corresponding to the peaks of the distribution appearing in the histogram as the first characteristic color and the second characteristic color. According to the above configuration, the control unit 11 can easily and accurately identify the characteristic color, which is the main color in a medium having a pattern.

[0058] 4. Second embodiment: The embodiment described so far is referred to as the first embodiment, and the second embodiment will be described below. Regarding the second embodiment, the description common to the first embodiment will be omitted. In the preparation process S1, the control unit 11 may generate, as the second pattern image data, a plurality of second pattern image data in which the shape of the pattern is made different according to the degree of distortion of the medium according to the position in the width direction D2 intersecting with the transport direction D1. Then, in the print production process S2, the control unit 11 may calculate the correction value by the comparison between the second captured image data and the second pattern image data for each position in the width direction D2, and apply the correction value according to the position in the width direction D2 to each of a plurality of colored images that are colored images and that have been deformed in advance according to the degree of distortion according to the position in the width direction D2.

[0059] The "degree of distortion of the medium according to the position in the width direction D2" refers to a tendency of distortion that is known in advance from the characteristics of the conveying unit 16 and the medium, such as the tendency that the fabric 30 stretches more toward the end of the endless belt 23 in the width direction D2, or the fabric 30 distorts to the right on the right side from the viewpoint from upstream to downstream. Here, it does not matter what the tendency of distortion is, but in any case, it is assumed that the control unit 11 recognizes in advance the tendency of distortion according to the position in the width direction D2. Then, the control unit 11 generates a plurality of second pattern image data according to the position in the width direction D2 by further performing a process of changing the shape of the pattern according to the degree of distortion of the medium according to the position in the width direction D2 on the second pattern image data generated by applying the first characteristic color and the second characteristic color to the binary image data as described above in step S140. In other words, the previously known distortion is generated in the shape of the pattern of the second pattern image data.

[0060] Fig. 9 is a diagram for explaining the second embodiment. Regarding Fig. 9, differences from Fig. 8 will be mainly described. According to Fig. 9, a plurality of second pattern image data 45a, 45b, 45c... are generated as the second pattern image data 45. The plurality of second pattern image data 45a, 45b, 45c... are a plurality of second pattern image data generated in the preparation process S1 by varying the shape of the pattern according to the degree of distortion of the medium according to the position in the width direction D2.

[0061] 9, in step S170, the control unit 11 compares the pattern unit area 54a of the second captured image data 54 with the second pattern image data 45a, which correspond in position in the width direction D2, to calculate a correction value. Similarly, the control unit 11 compares the pattern unit area 54b with the second pattern image data 45b, which correspond in position in the width direction D2, to calculate a correction value, and compares the pattern unit area 54c with the second pattern image data 45c, which correspond in position in the width direction D2, to calculate a correction value.

[0062] 9, a set of colored image data 60a, 60b, 60c... is generated as a set of a plurality of colored image data 60 arranged along the X-axis direction. That is, each of the colored image data 60a, 60b, 60c... represents a colored image that has been deformed in advance according to the degree of distortion corresponding to the position in the width direction D2. In the second embodiment, the colored image data 60a, 60b, 60c... may be generated in advance and the control unit 11 may acquire the colored image data from a predetermined acquisition source in step S180, or the control unit 11 may generate the colored image data 60a, 60b, 60c... from the colored image data 60 acquired in step S180.

[0063] Then, in step S180, the control unit 11 applies the correction value calculated from the comparison between the pattern unit area 54a and the second pattern image data 45a to the colored image data 60a to generate colored image data 61a after the colored image transformation. Similarly, the control unit 11 applies the correction value calculated from the comparison between the pattern unit area 54b and the second pattern image data 45b to the colored image data 60b to generate colored image data 61b after the colored image transformation. Thereafter, the control unit 11 similarly applies the correction value calculated from the comparison between the pattern unit area 54c and the second pattern image data 45c to the colored image data 60c to generate colored image data 61c after the colored image transformation.

[0064] According to the second embodiment, the control unit 11 uses, as the second pattern image data, a plurality of second pattern image data in which the shape of the pattern is different according to the degree of distortion of the medium according to the position in the width direction D2, and uses, as the colored image, a plurality of colored images that have been deformed in advance according to the degree of the distortion according to the position in the width direction D2. This simplifies the calculation of the correction value and the deformation due to the correction value, compared with the case where the same second pattern image data and colored image data are used regardless of the position in the width direction D2, and also makes it easier to avoid inconveniences such as errors caused by excessive deformation of the colored image. In some cases, the amount of deformation due to the correction value is almost 0. In the example of FIG. 9, priority is given to expressing the differences between the second pattern image data 45a, 45b, 45c... and the differences between the colored image data 60a, 60b, 60c..., and does not express visible deformation due to the correction value.

[0065] 5.Other notes: Even if only some of the combinations of claims are described in the claims, this embodiment naturally includes in its disclosed scope not only one-to-one combinations of independent claims and dependent claims, but also various combinations of multiple dependent claims. In addition to the printing device, this embodiment discloses inventions in various categories, such as a system, a method, and a program for implementing the method in cooperation with a processor.

[0066] For example, the printing method includes an imaging step of imaging a medium on which a pattern is formed and which is transported in a transport direction, a print production step including printing on the medium transported in the transport direction, and a preparation step for the print production step. The imaging step is included in steps S110 and S160. The imaging step in step S110 is called a first imaging step, and the imaging step in step S160 is called a second imaging step. In the preparation step, first pattern image data having information on the shape of the pattern and first captured image data generated by imaging the medium in the first imaging step are acquired, a first characteristic color and a second characteristic color brighter than the first characteristic color are identified from the first captured image data, the first pattern image data is binarized to generate binary image data by the first color and a second color brighter than the first color, the first color of the binary image data is replaced with the first characteristic color and the second color is replaced with the second characteristic color to generate second pattern image data, and feature points are set for edges of the pattern in the second pattern image data. Then, in the print production process, second captured image data generated by imaging the medium in the second imaging process is obtained, and based on a comparison between the second captured image data and the second pattern image data, correction values ​​for feature points required to match the shape of the pattern in the second pattern image data to the shape of the pattern in the second captured image data are calculated, the correction values ​​are applied to a colored image for coloring the pattern to deform the colored image, and the deformed colored image is printed on the medium imaged in the second imaging process. [Explanation of symbols]

[0067] 10...printing device, 11...control unit, 12...program, 15...imaging unit, 16...transport unit, 17...printing unit, 18...storage unit, 19...communication IF, 20...carriage, 22...print head, 30...textile, 40...first pattern image data, 44...binary image data, 45...second pattern image data, 50...first captured image data, 54...second captured image data, 60...colored image data

Claims

1. a conveying unit that conveys the medium on which the pattern is formed in a conveying direction; an imaging unit that images the medium being transported by the transport unit; a printing unit that prints on the medium transported by the transport unit; A control unit, The control unit is As a preparation process for a print production process including printing by the printing unit, acquiring first pattern image data having information on a shape of the pattern and first captured image data generated by capturing an image of the medium by the imaging unit; Identifying a first characteristic color and a second characteristic color brighter than the first characteristic color from the first captured image data; binarizing the first pattern image data to generate binary image data having a first color and a second color that is brighter than the first color; generating second pattern image data by replacing the first color of the binary image data with the first characteristic color and replacing the second color of the binary image data with the second characteristic color; setting feature points for edges of a pattern in the second pattern image data; The print production process includes: acquiring second captured image data generated by the imaging unit capturing an image of the medium; calculating a correction value for the feature point required to match a shape of a pattern in the second pattern image data to a shape of a pattern in the second pattern image data based on a comparison between the second captured image data and the second pattern image data; applying the correction value to a colored image for coloring the pattern to deform the colored image; a printing unit that causes the printing unit to print the transformed colored image on the medium that has been imaged by the imaging unit to generate the second captured image data;

2. 2. The printing device according to claim 1, wherein in the preparation process, the control unit generates a histogram of colors in the first captured image data, and identifies each color corresponding to each peak of the distribution appearing in the histogram as the first characteristic color and the second characteristic color.

3. The control unit is In the preparation process, a plurality of second pattern image data are generated as the second pattern image data, the second pattern image data having different shapes of patterns depending on the degree of distortion of the medium depending on the position in a width direction intersecting with the transport direction, 3. The printing device according to claim 1, wherein in the print production process, the correction value is calculated by comparing the second captured image data with the second pattern image data for each position in the width direction, and the correction value corresponding to the position in the width direction is applied to each of a plurality of colored images that have been deformed in advance according to the degree of distortion corresponding to the position in the width direction.

4. an imaging step of imaging the medium on which the pattern is formed, the medium being transported in a transport direction; a print production process including printing on the medium transported in the transport direction; a preparation step for the print production step, In the preparation step, acquiring first pattern image data having information on a shape of the pattern and first captured image data generated by capturing an image of the medium in the first imaging step; Identifying a first characteristic color and a second characteristic color brighter than the first characteristic color from the first captured image data; binarizing the first pattern image data to generate binary image data having a first color and a second color that is brighter than the first color; generating second pattern image data by replacing the first color of the binary image data with the first characteristic color and replacing the second color of the binary image data with the second characteristic color; setting feature points for edges of a pattern in the second pattern image data; In the print production process, acquiring second captured image data generated by capturing an image of the medium in the second imaging step; calculating a correction value for the feature point required to match a shape of a pattern in the second pattern image data to a shape of a pattern in the second pattern image data based on a comparison between the second captured image data and the second pattern image data; applying the correction value to a colored image for coloring the pattern to deform the colored image; a printing method comprising: printing the deformed colored image on the medium imaged in the second imaging step;

Images