Foreword

Digital image processing is an independent area of ​​knowledge that bistro develops in many countries, including the Soviet Union. The domestic industry produces image input and recording devices, displays, plotters, specialized processors, and other equipment. Powerful digital image processing centers have been established for the study of natural resources and environmental protection, and numerous digital equipment for medical diagnostics, including tomography, are in operation.

Image processing has to be dealt with by specialists of various profiles, and most of them become familiar with this subject on their own. In this regard, there is a need for appropriate training materials. There are many papers on digital image processing and related issues, but, as a rule, they are devoted to specific aspects of image processing, which naturally makes it difficult to choose literature.

Pratt’s monograph will undoubtedly be useful for Soviet specialists who are familiar with image processing techniques, hooks and for beginners. It compares favorably with other books on this topic in the full coverage of the material. It discusses most of the known methods and algorithms for image processing. However, digital image processing is so extensive and heterogeneous that it is completely impossible to fit it into one book. Thus, the monograph did not reflect some of the issues noted in the preface of the author, insufficiently considered statistical methods of image processing, which in recent years have been successfully used to improve and analyze images. We found it expedient to bring a list of articles and books published after the publication of this monograph. This list also includes the main works of Soviet authors, whose great contribution to image processing is reflected in the monograph completely inadequate.

There were great terminological difficulties in the translation. Although not all decisions made by the translation editor and translators can be considered indisputable, their work will undoubtedly contribute to the development and streamlining of terminology in the field of digital image processing.

The translation was made by V.P. Andreev (chap. 17–20), A.L. Zaitsev (chap. 4, 6, 7, 9, 10, 11), cand. tech. D.S. Lebedev (Ch. 1-3), Cand. tech. Sciences VG Polyakov (Ch. 21-24),

N. N. Tetekin (ch. 5, 8) and cand. tech. Sciences V.A. Khleberodov (Ch. 12-16).
Corr. USSR Academy of Sciences
V.I. Siforov

Over the past decade, the scope of digital image processing has expanded significantly. This was facilitated by increasing the speed of work, as well as reducing the cost and size of digital computers and technical means of signal processing. Image processing techniques are already playing a significant role in scientific research, industry, medicine, space research, and information systems. Examples of these methods include digital image transmission from spacecraft, video telephony via telephone channels, enhancing the clarity of images generated by an electron microscope, image distortion correction taken from space, automatic analysis of the nature of the terrain, the study of natural resources from photographs transmitted from Earth satellites , reinforcement and improvement of the quality of biological and medical images, including radiographs, thermograms and images, radioisotope Diagnostic second, automatic mapping from aerial photographs, detecting defects in the machine parts with industrial radiographs. There is no doubt that over time, image processing methods will find even wider application in medicine, in many cases making it easier for the doctor to make a diagnosis, and in the technique. The actions of the robot endowed with "vision" will be based on automatic scene analysis. Effective methods of image coding, apparently, will allow in the future to create individual channels of two-way television communications, both personal and business use.

This book is intended as a guide for the course “Digital Image Processing” for undergraduate and graduate students specializing in electronic and computer technology, and can also be used as a reference tool for researchers and engineers associated with image processing research and practice. . Digital image processing is a broad subject, encompassing issues of physics, physiology, electronic and computer technology, and mathematics. It is assumed that the reader has training in any of these areas, in the scope of the program of a technical college. It is highly desirable (but not necessary) to get acquainted with the theory of linear systems, vector algebra, probability theory and the theory of random processes. The book is divided into six parts. Part 1, consisting of three chapters, is devoted to continuous images. Here, a mathematical representation of a continuous image is given, the psychophysical properties of a person’s vision are described, and photometry and colorimetry are considered. Part 2 presents the methods of discretization and quantization, the questions of the mathematical description of discrete images and the choice of criteria for assessing the quality of the image. Part 3 discusses two-dimensional signal processing techniques. We consider generalized linear operators, pseudo-inversion, superposition, and convolution operators, as well as unitary transformation operators, in particular, the Fourier, Hadamard, and Karhunen-Lozva transformations. In the final chapter of part 3, we perform a comparative analysis of linear filtering methods based on direct calculation of convolution, Fourier transform and recursive filtering.

Part 4 describes the enhancement techniques in image restoration. To improve the images, operations are used, as a result of which the image becomes subjectively more acceptable for visual perception, or visual or machine image analysis is facilitated. The task of the restoration is to improve image fidelity by correcting the distortion. Part 5 focuses on link analysis and image interpretation. The tasks of identifying and measuring signs, detecting objects, combining images, symbolic description of images, as well as systems for understanding images are considered. Part 6 is devoted to the issues of image coding, carried out in order to reduce the number of binary units spent on the description of single-color and color images in the systems for transmitting and storing images. Although the monograph covers an extremely wide range of issues, many topics related to the field of image processing had to be dropped due to the limited volume of the book.

Among them, the most important are pattern recognition, digital holography and tomography. A bibliography on these issues is given in Appendix 1.

W. K. Pratt
Malibu, California.
January, 1978