A resolution-adjustable halftone amplitude modulation screening method for gravure printing

Abstract

The present invention discloses a resolution-adjustable gravure printing halftone amplitude modulation screening method. Users can customize output resolution, screen wall parameters, cell shapes, and other aspects to obtain halftone images that meet different needs. The main steps include: parameter definition, screen wall image generation, dot growth model definition, model optimization, image gradation optimization, and halftone processing. Compared with the prior art, the present invention addresses the shortcomings of outputting images with fixed resolutions by mapping (n*n) pixel blocks of the original image to (m*m) pixel blocks of the halftone image. Furthermore, by optimizing the image gradation, the actual printing effect is improved. Its advantages, such as low computational complexity and good results, make it extremely valuable in actual printing.

Description

Technical Field

[0001] The invention relates to the field of printing, in particular to a resolution-adjustable halftone amplitude modulation screening method for gravure printing. Background Art

[0002] Gravure printing is one of the four traditional printing methods and one of the current mainstream printing methods. Among them, halftone is the key technology for image printing output. In response to the current situation where only a few fixed resolution outputs are supported, a resolution-adjustable gravure printing halftone amplitude modulation screening method was invented.

[0003] This invention addresses dynamic resolution output by mapping the original image's (n*n) pixel blocks to the halftone image's (m*m) pixel blocks to produce the corresponding halftone image. This method changes the conventional one-to-many mapping approach, allowing users to obtain the corresponding halftone image based on actual printing needs and printer capabilities. This improves image print quality without increasing algorithm complexity.

[0004] The present invention is based on the above principles and has designed a complete set of algorithms to obtain halftone images, including the following steps: parameter definition, screen wall image generation, dot growth model definition, model optimization, image tone optimization to be processed, and halftone processing. Summary of the Invention

[0005] The purpose of the present invention is to meet actual printing needs and provide a resolution-adjustable halftone amplitude modulation screening method for gravure printing.

[0006] The technical solution adopted by the present invention to solve its technical problem is:

[0007] This method maps the original image (n*n) pixel blocks to the halftone image (m*m) pixel blocks, thereby overcoming the shortcomings of outputting images with fixed resolutions and improving the actual printing effect by optimizing the image gradation. The method includes the following steps.

[0008] (1) Parameter definition;

[0009] (2) Network wall image generation;

[0010] (3) Definition of dot growth model;

[0011] (4) Model optimization;

[0012] (5) Optimizing the tone of the image to be processed;

[0013] (6) Halftone processing;

[0014] Furthermore, a corresponding halftone image is obtained by mapping the original image (n*n) pixel block to the halftone image (m*m) pixel block.

[0015] Furthermore, the specific implementation method of the resolution-adjustable gravure printing halftone amplitude modulation screening method includes the following steps:

[0016] (1) Parameter definition

[0017] According to the actual printing output needs, the user specifies the corresponding output resolution, mesh wall, cell shape and other parameters;

[0018] (2) Web wall image generation

[0019] Mathematically model the parameters of the mesh wall and cell shape to generate a specified mesh wall image;

[0020] (3) Definition of dot growth model

[0021] For a single cell model, a specific method is used to separate the layers and perform spiral assignment from the inside to the outside, so that it has a good shape-preserving effect.

[0022] (4) Model optimization

[0023] The established dot growth model is locally optimized to ensure that the dots at each grayscale level meet the actual printing requirements; grooves can be added to the dark areas as needed to enhance the printed image effect;

[0024] (5) Tone optimization of the image to be processed

[0025] In order to reduce the demand for printing equipment capacity in actual printing and improve the quality of printed images, the bright parts of the image are concentrated so that the halftone image does not have too small dots.

[0026] (6) Halftone processing

[0027] The corresponding halftone image is obtained by mapping the original image (n*n) pixel block to the halftone image (m*m) pixel block.

[0028] Furthermore, for cells with holes, an interpolation sampling method is used to peel off the cells layer by layer, and for cells of general shape, a statistical field value sum method is used to peel off the cells.

[0029] Furthermore, the original image is adjusted in tone, and the pixels are clustered using an error diffusion algorithm with a random distribution sequence, starting from a specified tone according to custom parameters.

[0030] Furthermore, when half-tone processing is performed on an image, for pixels that have undergone tone processing, random dithering of the landing points is required during the half-tone processing process.

[0031] The beneficial effects brought by the present invention are:

[0032] This invention addresses dynamic resolution output by mapping the original image's (n*n) pixel blocks to the halftone image's (m*m) pixel blocks to produce the corresponding halftone image. This method changes the conventional one-to-many mapping approach, allowing users to obtain the corresponding halftone image based on actual printing needs and printer capabilities. This improves image print quality without increasing algorithm complexity. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The figure is an algorithm flow chart of a resolution-adjustable halftone amplitude modulation screening method for gravure printing in an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0035] An embodiment of the present invention provides a resolution-adjustable halftone amplitude modulation screening method for gravure printing. The method maps the original image (n*n) pixel blocks to the halftone image (m*m) pixel blocks, thereby overcoming the shortcomings of outputting images with fixed resolutions. Furthermore, by optimizing the image gradation, the actual printing effect is improved. The method includes the following steps.

[0036] (1) Parameter definition;

[0037] (2) Network wall image generation;

[0038] (3) Definition of dot growth model;

[0039] (4) Model optimization;

[0040] (5) Optimizing the tone of the image to be processed;

[0041] (6) Halftone processing;

[0042] In one embodiment of the present invention, a corresponding halftone image is obtained by mapping an original image (n*n) pixel block to a halftone image (m*m) pixel block.

[0043] In one embodiment of the present invention, a specific implementation method of the resolution-adjustable gravure printing halftone amplitude modulation screening method includes the following steps:

[0044] (1) Parameter definition

[0045] According to the actual printing output needs, the user specifies the corresponding output resolution, mesh wall, cell shape and other parameters;

[0046] (2) Web wall image generation

[0047] Mathematically model the parameters of the mesh wall and cell shape to generate a specified mesh wall image;

[0048] (3) Definition of dot growth model

[0049] For a single cell model, a specific method is used to separate the layers and perform spiral assignment from the inside to the outside, so that it has a good shape-preserving effect.

[0050] (4) Model optimization

[0051] The established dot growth model is locally optimized to ensure that the dots at each grayscale level meet the actual printing requirements; grooves can be added to the dark areas as needed to enhance the printed image effect;

[0052] (5) Tone optimization of the image to be processed

[0053] In order to reduce the demand for printing equipment capacity in actual printing and improve the quality of printed images, the bright parts of the image are concentrated so that the halftone image does not have too small dots.

[0054] (6) Halftone processing

[0055] The corresponding halftone image is obtained by mapping the original image (n*n) pixel block to the halftone image (m*m) pixel block.

[0056] In one embodiment of the present invention, for cells with holes, an interpolation sampling method is used to peel off the cells layer by layer, and for cells of general shape, a statistical field value sum method is used to peel off the cells.

[0057] In one embodiment of the present invention, the gradation of the original image is adjusted by using a random distribution sequence error diffusion algorithm to perform pixel clustering starting from a specified gradation according to user-defined parameters.

[0058] In one embodiment of the present invention, when half-tone processing is performed on an image, for pixels that have undergone tone processing, random dithering of the landing points is required during the half-tone processing.

[0059] The present invention will be further described in detail below with reference to the examples, but the present invention is not limited to the following examples.

[0060] Example 1: Honeycomb-shaped, 5080-resolution gravure halftone image

[0061] Reference Attachment Figure 1 , the method comprises the following steps:

[0062] (1) Parameter definition

[0063] According to the actual printing output needs, the user specifies the corresponding output resolution as 5080dpi, the mesh wall and the cell shape as honeycomb and other parameters;

[0064] (2) Web wall image generation

[0065] Mathematically model the parameters of the mesh wall and cell shape to generate a specified mesh wall image;

[0066] (3) Definition of dot growth model

[0067] For a single honeycomb cell model, a specific method is used to separate the layers and perform spiral assignment from the inside to the outside, so that it has a good shape-preserving effect.

[0068] (4) Model optimization

[0069] The established dot growth model is locally optimized to ensure that the dots at each grayscale level meet the actual printing requirements; grooves can be added to the dark areas as needed to enhance the printed image effect;

[0070] (5) Tone optimization of the image to be processed

[0071] In order to reduce the demand for printing equipment capacity in actual printing and improve the quality of printed images, the bright parts of the image are concentrated so that the halftone image does not have too small dots.

[0072] (6) Halftone processing

[0073] The corresponding halftone image is obtained by mapping the original image (n*n) pixel block to the halftone image (m*m) pixel block.

Claims

1. A resolution-adjustable halftone amplitude modulation screening method for gravure printing, characterized in that: The resolution-adjustable gravure printing halftone amplitude modulation screening method is a gravure printing screening method that can define the resolution according to actual needs, and the method comprises the following steps: (1) Parameter definition According to the actual printing output needs, the user specifies the corresponding output resolution, mesh wall, and cell shape parameters; (2) Web wall image generation Mathematically model the parameters of mesh wall and mesh cell shape to generate a specified mesh wall image; (3) Definition of dot growth model The single cell model is separated into layers. For cells with holes, the interpolation sampling method is used to peel off the cells layer by layer. For cells without holes, the sum of statistical field values ​​is used to peel off the cells. The spiral value is assigned from the inside to the outside to ensure good shape preservation. (4) Model optimization The established dot growth model is locally optimized to ensure that the dots at each grayscale level meet the actual printing requirements; through-grooves can be added to the dark areas as needed to enhance the printed image effect; (5) Tone optimization of the image to be processed In order to reduce the demand for printing equipment capacity in actual printing and improve the quality of printed images, the bright parts of the image are concentrated so that the halftone image does not have too small dots. (6) Halftone processing The corresponding halftone image is obtained by mapping the original image (n*n) pixel block to the halftone image (m*m) pixel block.

2. The resolution-adjustable halftone amplitude modulation screening method for gravure printing according to claim 1, characterized in that: Adjust the gradation of the original image. Starting from the specified gradation, the error diffusion algorithm with random distribution sequence is used to cluster pixels according to custom parameters.

3. The resolution-adjustable halftone amplitude modulation screening method for gravure printing according to claim 1, characterized in that: When half-toning an image, for pixels that have undergone tone processing, random dithering of the landing points is required during the half-toning process.

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