Method for producing a printing plate

Abstract

A method for manufacturing a printed board, comprising the steps of: selecting a digital image (100, IMGsel) having a continuous region of image pixels (107, Aimgpix) surrounded by a continuous region of non-image pixels (105, Aimgpix); determining a boundary (200, B) of the continuous region (107, Aimgpix); a first bezel region (207, BA1) according to the boundary (200, B) and within the continuous region of image pixels (107, Aimgpix); and a second bezel region (205, BA2) in accordance with the boundary (200, B) and within the continuous region of non-image pixels (105, Animgpix), and a second bezel region (205, BA2) in accordance with the boundary (200, B) and within the continuous region of non-image pixels (105, Animgpix); selecting N consecutive clusters (CLsel, 1.. N) from the first bezel region (207, BA1) and adapting the selected digital image (100, IMGsel) by moving each consecutive cluster (CLsel, 1) of the N consecutive clusters (CLsel, 1) to the second bezel region (205, BA2), selecting N consecutive clusters (CLsel, 1) from the first bezel region (207, BA1), and adapting the selected digital image (100, IMGsel) by moving each consecutive cluster (CLsel, 1) of the N consecutive clusters (CLsel, 1) to the second bezel region (205, BA2); the adapted digital image (IMGadp) is imaged on a plate precursor to form the printed plate.

Description

Technical Field

[0001] This invention relates to the technical field of printing plates, wherein printing quality is improved by adapting a digital binary image to the plate front body before imaging. Background Technology

[0002] In the field of printed circuit board technology, digital images are imaged onto a board precursor, such as a lithographic printing board precursor.

[0003] As part of conventional printing techniques, the use of a preform and the imaging of a digital image onto the preform to form a printing plate is well-known. Helmut Kipphan's "Handbook of Print Media" (ISBN 3-540-67326-1-Springer-Verlag Berlin Heidelberg New York) discloses several types of these conventional printing techniques, particularly in Chapter 1.3 "Printing technologies" and Chapter 2 "Printing Technologies with Permanent Printing Master." Imaging is sometimes also referred to as imaging exposure.

[0004] WO2010122042A1 (AGFA NV) discloses an example of how to manufacture a lithographic printing plate precursor and how to image a digital image on the plate precursor (by infrared radiation).

[0005] Another type of plate precursor is a flexographic printing plate precursor. Examples of how to manufacture such a precursor or how to image a digital image on the plate precursor by laser engraving are disclosed in WO2008074796A1 (AGFA NV).

[0006] In flexographic printing, the imaging precursor is primarily a photopolymer plate with raised or recessed patterns corresponding to the desired halftones. When ink is applied to the plate and transferred to the substrate, different depths on the plate create dots of varying sizes, thus producing the illusion of continuous tones.

[0007] The digital image projected onto the printing plate contains information that needs to be printed onto the printing medium using ink. The digital image contains image pixels and non-image pixels to determine the locations where ink must form on the printing medium when using a printing plate. For example, a pixel in the digital image can have a value of 1 if it is an image pixel, and a value of 0 if it is a non-image pixel.

[0008] To simulate a digital continuous-tone image, such as a photograph, on a printed medium using conventional printing techniques, the digital continuous-tone image is first half-toned using a half-tone technique. This generates a half-tone image comprising dots of varying size and / or spacing, formed to simulate the digital continuous-tone image. The formed dots are either image pixels or non-image pixels. This allows images to be printed using only a limited number of ink colors, as the eye blends the dots together to perceive the desired tone. An example of a half-tone technique is disclosed in WO2019081493A1 (AGFA NV), in which spiral half-tone dots with image pixels are formed. Furthermore, other half-tone techniques are disclosed in the "Handbook of Print Media" under Chapter 1.4.3 "Halftone Process / Screening" of Helmut Kipphan, mentioned above.

[0009] Halftone technology is typically used in raster image processors (RIPs) or in processors such as PrinectWorkflow from manufacturer HeidelbergDurckmaschinen aktien gesellschafttm. TM Or Apogee from manufacturer ECO3 TM This is implemented in a prepress workflow where files based on a page description language are converted into digital continuous tone images and halftone images, wherein the halftone images are transmitted to an imaging system for use in creating a printing plate from a plate preform (e.g., an image setter).

[0010] To ensure the simulation of continuous-tone images, they are linearized, also known as calibrated, before or during halftone processing. This is typically done using a dot gain (compensation) curve, which defines the percentage of each desired percentage used on the plate on the printing press. Linearization is used to control conventional printing techniques in such a way that the printed colors are linearly related to the input colors of the continuous-tone image.

[0011] The printing artifacts are found to have local density differences at the boundaries of the printed continuous areas of image pixels relative to the center of the printed continuous areas of image pixels in a digital image, and / or to have printing anomalies such as ghosting or halo printing. These printing artifacts depend on the printing media used and / or printing parameters of conventional printing techniques, such as greater pressure on the plate, less dampening solution, or more oily ink used during ink transfer via intermediate pressure rollers or directly to the printing media.

[0012] Therefore, there is a need for a solution that has fewer printing artifacts, is less dependent on the printing parameters, and preferably does not interfere with linearization. Summary of the Invention

[0013] The object of this invention is to provide a method for manufacturing a printing plate that exhibits excellent printability and overcomes the aforementioned printing artifacts. This invention also ensures that linearization performed before or during the halftone conversion of a continuous-tone image to be printed remains stable or identical.

[0014] This objective has been achieved by the method for manufacturing a printed circuit board as defined in claim 1.

[0015] Another embodiment of the present invention is a printing plate manufactured according to the method.

[0016] Other features, elements, steps, characteristics, and advantages of the invention will become more apparent from the accompanying drawings and the following detailed description of preferred embodiments. Specific embodiments of the invention are also defined in the dependent claims. Attached Figure Description

[0017] Figure 1 The illustration shows several steps of a preferred embodiment. The first step is to select a digital image (400, 100, IMG). sel ), which has a composition of non-image pixels (105, Å) nonimgpix Image pixels (107, A) surrounded by a continuous region imgpix A continuous region. Figure 2 This is a digital image (100, IMG) sel Example of ). From the digital image, (determine) the boundary; determine (401) the first border region and the second border region. The result of the determination is in Figure 3 and Figure 4 The following step is to adapt the (402) digital image (100, IMG) by moving the image pixels from the first border region (207, BA1) to the second border region (205, BA2). sel ),like Figure 5 , Figure 6 , Figure 7 and Figure 8 As shown in the illustration, the adapted digital image (300, IMG) will then be used. adp Imaging (403) on the plate front body.

[0018] Figure 3 The diagram shows... Figure 1 The image pixels shown (107, A) imgpix The defined boundary (200, B) of the continuous region.

[0019] Figure 4 The diagram shows... Figure 1 The selected digital image shown (100, IMG)sel The defined boundary (200, B), the first border region (207, BA1) between the inner dark line and the boundary (200, B), and the second border region (205, BA2) between the outer dark line and the boundary (200, B).

[0020] Figure 5 The steps of the preferred embodiment are illustrated, thereby creating a 1×1 continuous cluster (CL). sel，1..N Move from the first border region (207, BA1) to the second border region (205, BA2) as shown by the black arrow.

[0021] Figure 6 The diagram illustrates the relationship with Figure 4 The same steps, but with a different shape for continuous clusters (CL). sel，1..N ).

[0022] Figure 7 Diagram and Figure 5 The same steps, but with consecutive clusters (CL) in the first border region (207, BA1). sel，1..N The area is moved and divided into multiple parts to the second border area (205, BA2).

[0023] Figure 8 The additional steps are illustrated, in which the line pattern in the central region (209) is changed into non-image pixels according to the rules. Detailed Implementation

[0025] An embodiment of the present invention used to solve the above-mentioned printing artifacts is a method for manufacturing a printing plate, comprising the following steps: a) Select (401) which has non-image pixels (105, A) nonimgpix Image pixels (107, A) surrounded by a continuous region imgpix Digital images of continuous regions (100, IMG) sel ); b) Determine the continuous region (107, A) described in (402). imgpix The boundary of (200, B); and determine -Based on the boundary (200, B) and in the image pixel (107, A) imgpix The first border region (207, BA1) within the continuous region of ) and -Based on the boundary (200, B) and in non-image pixels (105, A) nonimgpix The second border region (205, BA2) within the continuous region of the ). c) Select N consecutive clusters (CL) from the first border region (207, BA1). sel，1..N ) and adapt (403: Figure 5 ; Figure 6 ; Figure 7 ; Figure 8 By using N consecutive clusters (CL) sel，1..N One (preferably each) consecutive cluster (CL) sel，i Move to the second border area (205, BA2) to select the digital image (100, IMG). sel ); d) Imaging on the plate front body (404) to adapt a digital image (300, IMG) adp (to form the printed plate.)

[0026] Specifically, N is a non-zero positive integer. The steps described are as follows: Figure 1 The diagram is shown in the image.

[0027] Therefore, in this embodiment, one or more image pixels of the first border region (207, BA1) are moved to the second border region (205, BA2) at a first position in the first border region (207, BA1). At the first position, one or more image pixels become non-image pixels, and vice versa, one or more non-image pixels become image pixels in the second border region (205, BA2).

[0028] By moving at the boundary (200, B), the image pixels (107, A) imgpix The continuous region towards the non-image pixels (105, Å) nonimgpix Smoothing of continuous regions of ) . Therefore, in digital images (300, IMG) adp After adaptation, the number of image pixels remains unchanged.

[0029] It can also determine continuous regions of image pixels (107, Å). imgpix ) within and in a contiguous region of non-image pixels (105, A nonimgpix Other boundary areas within ).

[0030] Furthermore, the movement at the boundary advantageously affects the ink layer thickness, because at the boundary (200, B) and also in the continuous region (107, A)... imgpix The ink buildup formed during internal printing has the opportunity to fill the non-image pixels formed in the first border area (207, BA1), thereby making the ink layer thinner and requiring less drying power depending on the conventional printing technology used.

[0031] Preferably, the plate preform is used for offset printing. More preferably, the plate preform is used for flexographic printing, where ghosting and halo printing present greater challenges.

[0032] One or more consecutive clusters (CL) sel，1..N The preferred distribution is that the components are evenly distributed in the first border region (207, BA1).

[0033] In a preferred embodiment, when the printing plate is used with a conventional printing technique, the printing direction is known. When installed in a system with said conventional printing technique, the plate front is primarily rectangular, and one side of the plate front is therefore parallel to the printing direction. The selected one or more consecutive clusters (CLs) sel，1..N It is preferable to position the printing plate essentially along a direction perpendicular to the printing direction, especially to avoid halo printing and ghosting printing.

[0034] In order to achieve the image pixels (107, Å) imgpix To achieve a more uniform print density in continuous printing areas, especially when using offset or flexographic printing techniques, N consecutive clusters (CL) sel，1..N The selection is preferably based on the following: a predetermined pattern, preferably a regular pattern, such as a tiled rectangle, ellipse, or rhombus, and / or each of N consecutive clusters having the same size and shape, such as an ellipse, rectangle, or rhombus. If more than the first and second border areas (207, BA1, 205, BA2) are determined, another pattern or other shape / size can be used for the other border areas.

[0035] plate precursor In a preferred embodiment, the plate preform is used for offset printing or flexographic printing.

[0036] A plate preform is a well-known technique in flexographic and offset printing, which uses digital imagery to form a printing plate through chemical and / or mechanical reactions. This printing plate is then used in systems capable of flexographic or offset printing, such as printing presses. Preferably, imaging is performed directly on the plate preform using a plate setter, but it can also be performed indirectly by exposing an intermediate film or digital mask panel on the plate preform, wherein the film or digital mask panel contains a representation of the digital image. The intermediate film can be made by an image setter. An example of a plate setter is the Avalon from manufacturer ECO3. TM The series or manufacturer MIRACLON's FLEXCEL NX Wide 5080 system. An example of an image setter is the ECO3 Avantra. TMThe series includes examples of digital mask panels disclosed in EP3608721A1 (AGFA NV). Examples of imaging flexographic precursors are disclosed in EP2539667A1 (MACDERMID PRINTING SOLUTIONS). An example of a process-free precursor is the Eclipse from manufacturer ECO3. TM .

[0037] Direct on-board processing is also known as computer-to-plate (CTP). Inkjet technology can be used here, also known as inkjet CTP. An example of inkjet CTP is disclosed in EP2097247A2 (AGFA NV).

[0038] Imaging can also be done on the printing press itself, which is called direct printing (DOP).

[0039] Digital Images Digital images are created using suitable commercial hardware (such as scanning photographs or taking images with a digital camera) and / or commercial software (such as Adobe Photoshop) used to process and create digital images. TM This is achieved through [the following]. Digital images can be logos, text, photographs, graphics, or a combination of (one or more) logos, text, (one or more) graphics and / or (one or more) photographs.

[0040] A digital image is a two-dimensional digital image with a specific size (width and height) and multiple pixels. Pixels are also called picture elements. Most digital images are organized into square grids, but rectangular or hexagonal grids are also possible. Each of the multiple pixels has a specific value representing intensity. The resolution (horizontal, vertical, hexagonal) of a digital image defines the number of pixels per centimeter or inch. Preferably, the (vertical and horizontal) resolution of a digital image is between 900 and 15,000 pixels per inch. For example, today, board setters capable of outputting printing plates at 9,600 pixels per inch are used for security printing (ultra-fine lines, ultra-small text, etc.). If only two values ​​can represent the intensity, the digital image is also called a binary digital image.

[0041] The content of a digital image can be defined in raster graphics formats such as Portable Network Graphics (PNG), Tagged Image File Format (TIFF), Adobe Photoshop Document (PSD), Joint Group of Image Experts (JPEG), or Bitmap (BMP).

[0042] Digital images can be stored as one or more files and / or loaded onto a computer's memory.

[0043] Digital images can be adapted by moving pixels from a first position to a second position; this is a common feature in digital image processing, especially in digital image editing. For example, in Adobe Photoshop... TM In Version 21.0.1, operators can use " Rectangular Marquee Tool "and use " Move Tool "You can select one or more pixels by dragging and dropping them from one location to another. In fact, after the movement, one or more pixels at one location become non-image pixels (shown as white), while at another location, the pixel's value is overwritten by the value of the selected pixel."

[0044] Preferably, the digital image is linearized to control conventional printing techniques in such a way that the printed colors are linearly related to the input colors of the continuous-tone image, especially when dot gain effects are present. Linearization can be achieved through tone mapping, a well-known method in digital image processing, thereby utilizing measurements of the printing test target. One advantage of this embodiment and the preferred embodiment is that the digital image (100, IMG)... sel The linearization of the digital image (300, IMG) adp After adaptation, they remain essentially the same because the number of image pixels remains the same.

[0045] In a preferred embodiment, the value of the moved image pixel is preferably adapted to a higher brightness, but the image pixel remains stationary. Therefore, the adapter is needed to drive the plate setter or image setter. At the location of the moved image pixel with the adapted value, the chemical and / or mechanical reactions occurring simultaneously with the formation of the printed circuit board will differ from those of the unmoved image pixel, for example, with fewer chemical and / or mechanical reactions. Fewer chemical and / or mechanical reactions can, for example, result in a smaller height after precursor imaging for flexographic printing.

[0046] a) Halftone image Digital images are preferably halftone images, also known as raster images. Halftone images are suitable for presenting continuous-tone images, that is, they produce the illusion of continuous-tone images on printed copies.

[0047] Halftone images preferably include halftone points, more preferably halftone points selected from the following list: AM points (amplitude modulation points) and / or XM points (cross-modulation points) and / or semi-random location points, such as (clustered) FM points (frequency modulation points) and / or DM points (digital modulation points).

[0048] Halftone dots can be arranged according to regular tiles or partially semi-randomly.

[0049] b) Continuous regions of (non-)image pixels A continuous region of image pixels (107) is a region of connected image pixels used to form the continuous region. Non-image pixels are not part of such a continuous region of image pixels.

[0050] A contiguous region of non-image pixels (105) is a region of connected non-image pixels used to form the adjacent region. Image pixels are not part of such a contiguous region of non-image pixels.

[0051] In a preferred embodiment, non-image pixels (105, Å) nonimgpix The continuous region of the image has more than one image pixel, and more preferably at least nine non-image pixels.

[0052] Non-image pixels (105, Å) nonimgpix The number of non-image pixels in a continuous region is preferably greater than that of image pixels (107, Å). imgpix The number of image pixels in a continuous region.

[0053] The selected N consecutive clusters (CL) sel，1..N The total number of image pixels in ) is less than the image pixels (107, Å) imgpix The number of image pixels in a continuous region.

[0054] If the selected digital image (100, IMG) sel If a halftone image includes multiple halftone dots, then the image pixels (107, Å) are... imgpix The selected continuous region can be one of the plurality of halftone dots. The shape of the halftone dots can be circular, elliptical, rectangular, rhomboid, oblique, spiral, single-ring, or double-ring. The shape affects tonal transitions and visual artifacts, such as moiré patterns, in printed digital images.

[0055] In a preferred embodiment, the image pixels (107, Å) imgpix The continuous region of the image pixel is more than one image pixel, and more preferably at least nine image pixels. In particular, when the continuous region of the image pixel is a halftone point in the highlight area, it is found that it is better to retain the halftone point rather than move the image pixel to the second border region (205, BA2).

[0056] c) Boundary (200, B) In halftone imaging, the boundary refers to the transition between two different tonal levels in a halftone image.

[0057] Several known image boundary detection methods exist in image processing, such as edge detection (e.g., Canny edge detection); thresholding, which involves setting a threshold and then highlighting all pixels in the image that exceed that value. This can create binary boundaries that separate image regions; morphological operations, such as dilation and erosion; and contour detection, which involves identifying the boundaries of objects in an image by detecting curves that connect points of similar color or intensity. Examples of methods for determining boundaries are disclosed in *Image Boundary Detection Using the Modified Level Set Method and a Diffusion Filter*, by S. Anam, E. Uchino, and N. Suetake, Procedia Computer Science, Vol. 22, 2013, pp. 192-200, ISSN 1877-0509.

[0058] If digital image (100, IMG) sel For imaging on a plate front to form a printed circuit board, a binary digital image is preferred. To determine the boundaries, the digital image can be converted into an 8-bit grayscale image, and then a convolutional filter can be applied, where the kernel size is equal to a predetermined bounding box. The result is an image with pixels whose original value is 255, and whose filtered value is not equal to 255. These define the boundaries of continuous regions of image pixels.

[0059] In a preferred embodiment, the convolution filter uses a square or circular convolution mask, wherein more preferably, the values ​​in the kernel are all 1.

[0060] d) Border area (205, BA1, 207, BA2) In the context of image processing, the border region of a continuous area of ​​(non)image pixels refers to the pixels or area surrounding the boundary of the continuous area. The shape of the boundary is more or less similar to the shape of the border region.

[0061] Using convolutional filtering as described in Chapter c) under Boundaries, you can also determine border regions at the boundaries of consecutive areas of (non)image pixels, for example, by adapting the kernel size, such as multiplying the requested border size range by 2 + 1. By using two convolutions with different kernel sizes, a border region with a chosen thickness (sometimes referred to as width or depth) can be determined in consecutive areas of the (non)image pixels.

[0062] Here's an example of how to define border regions BA1 and BA2 close to the boundary: The binary image is converted into an 8-bit grayscale image.

[0063] A convolutional filter will be applied based on the requested border region thickness, where the kernel size is equal to (requested border range x 2 + 1).

[0064] Before applying the filter, all pixels will have a value of 255 (black) or 0 (white). After convolution with the filter, four types of pixels can be defined: a. Pixels that were initially 0 and are now ≠ 0 (a continuous area close to the image pixels, which can be used as the second border area BA2). b. Pixels that were initially 0 and are now = 0 (part of a continuous region that is not an image pixel); c. The initial value was 255 pixels, but now it is not equal to 255 pixels (boundary); d. Originally 255 pixels and now = 255 pixels (within a continuous area of ​​image pixels).

[0065] When dealing with a contiguous region close to an image pixel, we want to group one or more contiguous clusters (CLs). sel，1..N If the moved position differs from the requested bounding box range, filters with different kernel sizes require two convolutions. The convolution mask can be square or circular. The values ​​inside the kernel are all 1.

[0066] The border area preferably has the same distance between its edges (more or less) (= the same thickness / the same width / the same depth), and the edges are along the boundary.

[0067] In a preferred embodiment, if a continuous region of non-image pixels is larger than a continuous region of image pixels, the thickness (also called width or depth) of the border region (205, BA2) is equal to or greater than the thickness (also called width or depth) of the first border region (207, BA1).

[0068] e) Continuous clusters In this embodiment, the selected contiguous cluster (CL) sel，i It contains one or more image pixels, preferably up to 32 image pixels, more preferably up to 16 image pixels, and most preferably up to 8 image pixels. Smaller, consecutively clustered selections better avoid print quality issues and the selection of digital images (100, IMG). sel The loss of details in )

[0069] The one or more selected consecutive clusters (CL) sel，i Each of the selected clusters (CLs) has a specific size, also known as dimensions and shape. The size and shape can be defined by a chosen pattern (e.g., a 2×2 pattern). Preferably, for all selected one or more consecutive clusters (CLs)... sel，1..NThe size and shape are the same. Here, N is a positive integer greater than zero.

[0070] The total number of image pixels in one or more consecutive clusters is preferably less than 75% of the total number of image pixels in the first border region (207, BA1).

[0071] Preferably, if more than one consecutive cluster is selected and more preferably evenly distributed in the first border region (207, BA1), then the selected one or more consecutive clusters (CL) sel，1..N ) are spaced apart from each other. One or more consecutive clusters (CL) sel，1..N The selection can be made using an image mask placed on the first border region (207, BA1) to identify the one or more consecutive clusters (CL). sel，1..N The location of the continuous cluster (CL). sel，1..N The selection can be based on a pattern (e.g., a chessboard) within the first border region (207, BA1) or a pseudo-random method (e.g., using a blue noise mask within the first border region (207, BA1)).

[0072] Preferably, the selected one or more consecutive clusters (CL) sel，1..N () is separated from the boundary.

[0073] Preferably, a mobile, continuous cluster (CL) mov，1..N The groups are spaced apart from each other, and more preferably evenly distributed within the second border region (205, BA2). The moving, continuous clusters (CL) mov，1..N Preferably, it is pseudo-randomly expanded in the second border region (205, BA2).

[0074] In the preferred embodiment ( Figure 7 ), having selected contiguous clusters (CL) with more than one image pixel sel，i At least one of the selected consecutive clusters. - Move to the second border region (205, BA2) without splitting; or - Divide into multiple parts, and move the multiple parts that are separated from each other to the second border area (205, BA2), thereby more preferably, at least one of the moved parts is connected to the boundary.

[0075] In the preferred embodiment ( Figure 8 ), determine the first border region (207, BA1) and image pixels (107, A) imgpixThe image pixels (107, A) are changed to non-image pixels according to a predetermined regular pattern in the center region (209) between the centers of the continuous regions of the image pixels (107, A). The changing step causes the image pixels (107, A) to be changed to non-image pixels. imgpix Larger, continuous areas result in better printing uniformity. The larger, continuous area of ​​image pixels is preferably greater than 50 image pixels, more preferably greater than 200 image pixels. The regular pattern can be regularly spaced lines, dots, stars, spirals, or any other geometric structure. Regularly spaced lines preferably have a maximum thickness of 8 pixels. The regularly spaced lines can be angled, and preferably at an angle of 45 or 135 degrees relative to the printing direction. Regularly spaced dots preferably have a maximum size of 8×8 pixels. The regularly spaced dots can also represent broken lines. The broken lines preferably have an angle of 45 or 135 degrees relative to the printing direction.

[0076] Step d) of this embodiment and its preferred embodiment may include image pixels (107, A) with long boundaries (200, B) in particular. imgpix Additional steps for continuous regions: - Select M other consecutive clusters from the first border region (207, BA1), and adapt the selected digital image (100, IMG) by changing the image pixels of the M other consecutive clusters to non-image pixels. sel Therefore, M is a non-zero positive integer. A long boundary means more than 40 pixels, and more preferably more than 80 pixels.

[0077] In a preferred embodiment, one or more selected contiguous clusters (CLs) 1..N Each consecutive cluster moves along the axis from the center of the consecutive region of the image pixels and the position of the selected consecutive cluster.

[0078] The distance traveled along the axis is preferably a maximum of 300% of the distance from the selected consecutive cluster locations and boundaries along the axis, more preferably a maximum of 200%.

[0079] In a preferred embodiment, up to 50%, more preferably up to 20%, of the image pixels in the first border region (207, BA1) are moved to the second border region (205, BA2).

[0080] Industrial applicability This invention relates to the technical field of printed circuit boards, and therefore satisfies industrial applicability.

Claims

1. A method for manufacturing a printed circuit board, comprising the following steps: - Select (401) with non-image pixels (105, A) nonimgpix Image pixels (107, A) surrounded by a continuous region imgpix Digital images of continuous regions (100, IMG) sel ); - Determine (402) the continuous region (107, A) imgpix The boundary of (200, B); Based on the boundary (200, B) and in the image pixel (107, A) imgpix The first border region (207, BA1) within the continuous area of ​​the image; and according to the boundary (200, B) and in non-image pixels (105, A) nonimgpix The second border region (205, BA2) within the continuous region of the ). - Select one or more consecutive clusters (CL) from the first border region (207, BA1). sel，1..N ), and by moving one or more selected consecutive clusters (CL) sel At least one consecutive cluster (CL) in 1) sel，i (403) to adapt (403) the selected digital image (100, IMG) to the second border region (205, BA2). sel ); - Imaging on the plate front body (404) to fit a digital image (300, IMG) adp (to form the printed plate.) 2. The method according to claim 1, wherein, Selected one or more consecutive clusters (CL) sel，1..N They are spaced apart from each other.

3. The method according to any one of claims 1 to 2, wherein, Mobile continuous cluster (CL) mov，1..N They are spaced apart from each other.

4. The method according to any one of claims 1 to 3, wherein - One or more consecutive clusters selected (CL) sel，1..N The positions of the clusters are evenly distributed within the first border region (207, BA1); or one or more selected consecutive clusters (CL) sel，1..N The pattern is selected according to a predetermined set of rules.

5. The method according to any one of claims 1 to 4, wherein, Selected one or more consecutive clusters (CL) sel，1..N Each of them has the same size and shape.

6. The method according to any one of claims 1 to 5, wherein, Selected one or more consecutive clusters (CL) sel，1 At least one consecutive cluster in the boundary (200, B) is connected to the boundary.

7. The method according to any one of claims 1 to 5, wherein, Selected one or more consecutive clusters (CL) sel，1..N Each of the elements is spaced apart from the boundary.

8. The method according to any one of claims 1 to 7, wherein, The selected one or more contiguous clusters (CLs) having more than one image pixel sel，i The portion is moved to the second border region (205, BA2) without being divided; or it is divided into multiple portions and the portions separated from each other are moved to the second border region (205, BA2).

9. The method according to claim 8, wherein, At least one of the multiple moving parts is connected to the boundary.

10. The method according to any one of claims 1 to 12, wherein, Determine the first border region (207, BA1) and the image pixels (107, A). imgpix The center region (209) between the centers of the continuous regions, and multiple image pixels according to a predetermined rule pattern in the center region (209) are changed into non-image pixels.

11. The method according to any one of claims 1 to 12, wherein, Step d) includes the additional step of: selecting M (M > 1) other consecutive clusters from the first border region (207, BA1), and adapting the selected digital image (100, IMG) by changing the image pixels of the M other consecutive clusters to non-image pixels. sel ).

12. The method according to any one of the preceding claims, wherein, Selected one or more consecutive clusters (CL) 1..N Each of the consecutive clusters described in the image (107, A) is along the path from the image pixel (107, A). imgpix The axis moves from the center of the continuous region to the position of the continuous cluster.

13. The method according to any one of the preceding claims, wherein, The digital image (100, IMG) sel ) is a halftone image with multiple halftone points; and The halftone points among the plurality of halftone points are image pixels (107, Å). imgpix The selected continuous region, and thus the plurality of halftone points are regularly tiled or semi-randomly positioned.

14. The method of claim 10, wherein, Image pixels (107, Å) imgpix The shape of the selected continuous region is circular, elliptical, rectangular, rhomboid, spiral, single-ring, or double-ring.

15. The method according to any one of the preceding claims, wherein, The plate preform is used for offset printing or flexographic printing.

Images