With the multimedia display of images and records, the exchange of image information between various media becomes more and more important. The quality of a color image reproduced in a medium depends on various technologies of the color reproduction system. And these technologies contain all aspects related to image reproduction. The following author mainly analyzes from the following aspects.

1. Selection of image data format

For a long time, the evaluation of image quality has been judged by visual and subjective influences, which inevitably leads to instability in judgment. Therefore, in order to have a standard basis, using some standard image data format will reduce the instability of image judgment. At present, IS012640 standard color image data format is generally recommended. It is an image data format used by color desktop systems, high-end networking systems, various output devices, and digital printing systems, and has nothing to do with devices.

For a widely used computer-to-plate system, standard color image data (using IS012640 standard color image data format) is a very useful standard language. It provides users with image data that has nothing to do with the original, input and output devices, and various image processing systems and input devices. Post-processing procedures and color reproductions produced by them not only provide observable, comparable, detectable means, but also provide operational, universal data standards.

In this way, by performing image reproduction between different media, relatively accurate judgments can be made and undue errors brought about by subjective judgments can be reduced, so as to facilitate improvement of image reproduction quality in the process of image reproduction.

2. Theoretical basis for color reproduction

From other media to print media, it is the main aspect of color image reproduction. The essence of color image printing is color dot printing, and the light and shade levels of color images are represented by the dot area rate, that is, the hue of the screen is reflected by the ratio of dot area ratios of C, M, Y, and K color versions.

There are generally two commonly used methods for dot color reproduction: one is the Neugebauer equation established based on a halftone microstructure, and the other is a masking equation that does not consider the specific structure of the nettone print product. However, the preconditions for the realization of these two methods are assuming that the law of superposition and proportionality of optical density holds. In practice, the correction of the Neugebauer equation is commonly used to describe the reproduction of colors.

It is also worth noting that the moiré often appearing in dot printing has a great influence on the reproduction quality of the image. Therefore, in order to reduce the impact on the reproduction of color images, a specific screen angle is often used in printing, ie, C version 45°, M version 15°, Y version 0°, K version 75°, and dot line count. It is also necessary to reach 70-80 lines/cm in order for the reproduced image to meet the requirements.

3. Play the role of black version in reproducing images

In the process of color image reproduction, whether the black edition is appropriate or not will directly affect the quality of the reproduced image. In the process of color reproduction, the prominent role of the black version is as follows: (1) Strengthen the density contrast of the image and expand the brightness range. This will increase the total image density range, improve the three-dimensional image and space effects, so that the image reproduction quality can be effectively guaranteed. (2) The black version can stabilize the tone of the middle tone to dark tone. For the reproduction of a color image, a skeleton black plate is usually used to enhance the outline of the image, and the specific use can be determined according to the characteristics of the image to be reproduced. The use of an appropriate black plate for superposition can also overcome the problem of darker tone and increase the satisfaction of the reproduced image. (3) The black version can increase the tone of the middle tone to dark tone. Due to the strong resolving power of darkness in vision, in the reconstructed image, if the level of intermediate tone to dark tone cannot be pulled open, there is a parallel level phenomenon, and the use of the black version can solve this problem to some extent.

4. A deep understanding of the importance of the image hierarchy

The image hierarchy refers to the density level from the brightest to the darkest in the image. Image hierarchy is a problem that involves the entire color reproduction process, and its importance is evident.

From manuscripts to prints, the process of color decomposition, flattening, copying, printing, and color synthesis involves the leveling of manuscripts. If the level deviation of a link exceeds the specified range, it will affect the follow-up. In all the processes, the final level of the image is certainly difficult to maintain. Obviously, in the entire process of operation, advanced equipment, excellent raw materials, scientific processes and technologies. The close cooperation between platemaking and printing is an indispensable prerequisite.

In general, the greater the number of levels that an image reproduced in a print can be discerned, the better the level of the weekly image in the print, and the better the image reproduction effect.

In short, the color, tone, gradation, and clarity of an image constitute its ultimate reappearance appearance characteristics. Whether or not the reconstructed image can achieve color tone coordination, clear gradation, and reality without fluttering, is the pursuit of color image reproduction quality. aims.