Anti-physical screening technology suitable for artistic printing

As we all know, printed images are represented by two-dimensional structures. The three-dimensional screening technology is aimed at printed images. By precisely controlling the generation of dots, the effect of reproducing three-dimensional images in printed images can be achieved. The basis of three-dimensional screening technology is still the orderly jitter and error diffusion technology commonly used in computer network technology. In the specific implementation process, non-traditional algorithms are used. After the shape of the dot, the angle of the screen, and the number of screens are determined, the computer automatically matches the screen template stored in the buffer, finds the closest point network template, and generates the network points. The shape of the dot is controlled by a dither matrix. The dither matrix may originate from a template that was previously stored in the buffer, or may be generated by the computer temporarily. The realization of the screening angle and the number of screen lines is completely controlled by the template matching function. The entire algorithm uses a combination of geometric transformations. Template matching and effect dyeing and other means, so that the screen image as much as possible three-dimensional effect, improve the visual appearance of the image.

A mesh tone image generated by ordinary screening technology has a clear tone and hierarchy, but lacks a three-dimensional sense. FIG. 4b is a three-dimensional screening image generated by using a three-dimensional screening technology, which not only has distinct levels and levels, but also has Obvious stereoscopic visual effects, more vivid and realistic, more in line with people's visual physiological habits.

Imitation physical screening technology

Imitation physical screening is the use of special network points instead of ordinary network to screen the image. The biggest difference between it and Art Screening is that the network points it uses are closely related to the overall image to be represented. Therefore, the mesh shape generation algorithm of the simulated object screening has an adaptive feature and can flexibly select the mesh point according to the content of the screening image. For example, when the printed image is a wall, a brick-like mesh point can be selected; when the printed image is a curved shape, a curved mesh point can be selected, so the simulated mesh-increasing algorithm is more complicated than the art-increasing algorithm.

Imitation nets are used to replace nets with multiple graphics. According to the texture of the screen images, a net point similar to the texture stripe is selected for screening. The process of imitation screening includes three steps. The first step is to generate the contour line according to the texture of the image, that is, the stroke, the density in the contour line is uniform, and the second step is the dyeing, that is, the calculation based on the pixel gray value calculation The brightness distribution of the edge area, that is, the density distribution; the third step is fusion, image fusion is performed on the contour line and the dyed area, and finally a simulated screen image is formed.

The network formed by the imitation of physical screening technology helps the human eye to understand the image information, and greatly reduces the visual failure of the image caused by the dot shape, giving a realistic feeling and is particularly suitable for the screening of artistic prints.

In the future, with the development of computer technology and the improvement of computing speed, especially the continuous improvement of new types of screening algorithms, the types of special screening technologies will become more and more abundant, more and more practical, and they are expected to be widely used in ordinary printed materials. application.