Examples of special screening technology for print

Reproduction of prints with different uses - examples of special processing technology

processing technology is the basic way to reproduce continuous tone images, and it is also an important technology to determine the quality of prints. It has a history of more than 100 years in the printing field, and has experienced the development stages of glass screen, contact screen, electronic processing, digital processing, and has formed rational processing, irrational processing, super cell structure processing, frequency modulation processing and other technologies. At present, amplitude modulation plus and frequency modulation plus as two major mainstream plus technology has been playing a leading role. With the development and progress of science and technology, some special processing technologies continue to appear, and have been applied in some printing fields, reproducing prints with different uses. This paper introduces these special processing technologies

hybrid addition technology

as we all know, amplitude modulation addition reproduces the image order and level by changing the point size through fixed point spacing, which has obvious advantages for the restoration of image halftone. FM plus reproduces the image order and level by changing the point spacing through fixing the point size, which can restore the details of the image well. Hybrid plus technology is a new plus technology developed by combining the advantages of AM plus and FM plus

hybrid addition is developed on the basis of digital addition principle and computer control technology. Its principle is to generate frequency modulation points in the high-key and dark part of the image, and the middle part simulates the configuration of amplitude modulation points, that is, while maintaining a certain number of points, it realizes the reproduction of tone by changing the size of a single point. Hybrid plus technology makes full use of the advantages of FM plus, while maintaining the good printability of AM points. Therefore, using hybrid plus technology can achieve good image reproduction effect

the points generated by the hybrid addition technology take the AM points as the skeleton and the FM points as the decoration. The shapes of the points are different, and the positions are slightly randomly distributed, which has the characteristics of both AM and FM points. The advantage of hybrid addition is that there is no point angle and direction problem, the low-frequency components are reduced to reduce the graininess of the picture, and the high-frequency components are reduced to improve the printing stability. Therefore, the printability of mixing point is better than that of AM point and FM point

art plus technology

the basic principle of art plus technology is to replace conventional points with graphics or patterns of various shapes to achieve the purpose of reproducing image levels. The commonly used point shapes in general addition technology are generally circular, oval, diamond or square, and the formation of point shapes is controlled by point functions. According to postscript plus principle, the mathematical model of point function can be adjusted to flexibly control the shape of points, which is the mathematical theoretical basis of art plus technology

art addition is to describe the outline of the figure or pattern as a point according to a certain algorithm, and then use the expansion, reduction or other nonlinear transformation algorithms for the outline to make the contour curve correspond to the gray value of the image one by one, and finally use the figure or pattern described by the outline to complete the addition of the image. In the high-profile part of the image, the edge of the point contour is fish shaped; The dark part adopts the reverse point, and the outline of the blank part is goose shaped; While the middle part uses fish shape and wild goose shape to represent the inked part and blank part respectively. Change the control so that the mathematical model of the point shape of EQ1 electric vehicle, which has widely used aluminum technology, can change the fish shape and wild goose shape into other shapes, such as various line patterns, so as to enrich the variety of artistic additions

art plus technology is most suitable for large outdoor posters and advertising paintings. People can see the overall image effect of the picture from a distance, and can learn the special information contained in the point from a nearby place. In addition, anti-counterfeiting printing is also suitable for art plus, which prints micro text or icons (trademarks) in the image as point shapes. Because the point contour algorithm is unique, it can play a certain anti-counterfeiting role. If the anti-counterfeiting image printed after dot is replaced by micro text, the small text hidden in the image can be clearly seen with the help of a magnifying glass, thus playing the role of identifying the authenticity

three dimensional addition technology

as we all know, printed images use two-dimensional structure to express information. China's plastic extruder industry is moving towards a healthy and sustainable development. Three dimensional addition technology is aimed at printed images and achieves the effect of reproducing three-dimensional images in printed images by accurately controlling the generation of points

the basis of 3D addition technology is still the ordered jitter and error diffusion technology commonly used in computer eye adjustment technology. In the specific implementation process, non-traditional algorithms are used. After determining the point shape, adding angle and adding line number, the final result is that the component can easily bear the mechanical load related to the start-up process. The calculator automatically matches the adding template stored in the buffer, finds the point template closest to the input, and then generates the point. The shape of the point is controlled by the jitter matrix, which may come from the template stored in the buffer in advance, or may be temporarily calculated and generated by the computer. The implementation of adding angle and number of lines is completely controlled by the template matching function. In the whole algorithm, geometric transformation, template matching, effect dyeing and other hand teaching mechanics center segments are comprehensively used, so that the added image can show three-dimensional effect as much as possible, and improve the visual appreciation of the image

compare ordinary plus with three-dimensional plus. The eye tone image generated by ordinary addition technology, although the order and level are clear, but it lacks the sense of three-dimensional; The three-dimensional plus image generated by the three-dimensional plus technology not only has clear order and level, but also has obvious stereo visual effect, which is more vivid and realistic, and more in line with people's visual physiological habits

real object adding technology

real object adding is to add images with special points instead of ordinary points. The biggest difference between it and art adding is that the points it uses are closely related to the overall image it wants to represent. Therefore, the point shape generation algorithm of simulated object addition has adaptive features, and can flexibly select the points used according to the content of the added image. For example, when the printed image is a wall, brick like points can be selected, as shown in Figure 5A; When the printed image is an arc, curve points can be selected. Therefore, the real object adding algorithm is more complex than the art adding algorithm

the imitation object is added with graphics instead of points. According to the texture of the added image, select points similar to the texture stripes to add. The process of adding simulated objects includes three steps, as shown in Figure 6. The first step is to generate contour lines according to the image texture, that is, tracing, and the density in the contour lines is uniform; The second step is dyeing, that is to calculate the brightness distribution of the traced area according to the pixel gray value, that is, the density distribution; The third step is fusion. The contour line and the dyed area are fused to form an imitation object plus image

the points formed by the imitation object addition technology help the human eye understand the image information, and greatly reduce the image visual failure caused by the point shape, giving people a realistic feeling, especially suitable for the addition of art prints

several special addition technologies are introduced above. In the future, with the development of computer technology and the improvement of operation speed, especially the continuous innovation of new addition algorithms, the types of special addition technologies will become richer and more practical, and are expected to be widely used in ordinary printing

source: designed and printed in China