The principle of image information processing

Image information refers to the process of acquiring image information by certain technical means, and performing some analysis and transformation on it to obtain the required residence.

There are two major categories of image information processing methods: (1) Optical image information processing, that is, the use of optical methods to perform certain special optical transformations on analog images. This is the most typical type of analog image information processing. However, this book does not discuss it. (b) Digital image processing, that is, the use of computers for image transformation and analysis. The digital image information here is further divided into two forms of analog electrical signal-only digital signal. With the advancement of technology, digital information has become the mainstream.

Generally, the computer has the following three main purposes for the processing of image information. The first is the improvement of the image quality (abbreviated as the image quality improvement), that is, some transformation of the gray level of the image, enhancing the useful information therein, and suppressing uselessness. Information, and output in an appropriate way, to improve the visual quality of the image, to facilitate the human eye to observe and understand and further processing, this is the focus of this book's research. The second is pattern recognition, which uses some special means to extract, describe and analyze certain features or special information contained in the image, such as the spectral characteristics, grayscale features, boundary features, color features, texture features, and shapes of the image. Features, topological features, and relational structures, etc., to achieve automatic image recognition. The third is image reconstruction, which is a technique for reconstructing an N-dimensional image from a certain algorithm from projection information of an N-dimensional image or microwave self-information (N-1 dimensional information).

Although the methods of image information processing are various, the basic structure is the same regardless of the method used. As shown in Fig. 2.1, the image information of the information source (original) is firstly obtained (density f(D) ), collected by the image information input system, and processed and transformed into the image information processing system in a certain form, and then performing various processing on the input information according to the final purpose, and finally processing the information in a certain form by The output of the image information output system is used by the image processing user, so that all the tasks of the image processing are completed.

The electronic color separation machine for the purpose of color image processing has some unique features in addition to the functions of the general image information processing system. The image processing of the electronic color separation camera is shown in Figure 2.2. That is, the color characteristics of the color image should be maintained in the image input system first, and the image should be decomposed into three primary colors (R, G, B/Y, M, C). As a set of parallel processing, the color image is converted into three monochrome monochrome images. In this way, the image processing method can be used to process it. However, due to the decomposition of the three graphic colors, the relationship between them needs to be taken into consideration, and the external processing method has certain limitations.