%0 Journal Article
%T Fast Transforms in Image Processing: Compression, Restoration, and Resampling
%A Leonid P. Yaroslavsky
%J Advances in Electrical Engineering
%D 2014
%R 10.1155/2014/276241
%X Transform image processing methods are methods that work in domains of image transforms, such as Discrete Fourier, Discrete Cosine, Wavelet, and alike. They proved to be very efficient in image compression, in image restoration, in image resampling, and in geometrical transformations and can be traced back to early 1970s. The paper reviews these methods, with emphasis on their comparison and relationships, from the very first steps of transform image compression methods to adaptive and local adaptive filters for image restoration and up to ¡°compressive sensing¡± methods that gained popularity in last few years. References are made to both first publications of the corresponding results and more recent and more easily available ones. The review has a tutorial character and purpose. 1. Introduction: Why Transforms? Which Transforms? It will not be an exaggeration to assert that digital image processing came into being with introduction, in 1965 by Cooley and Tukey, of the Fast Fourier Transform algorithm (FFT, [1]) for computing the Discrete Fourier Transform (DFT). This publication immediately resulted in impetuous growth of activity in all branches of digital signal and image processing and their applications. The second wave in this process was inspired by the introduction into communication engineering and digital image processing, in the 1970s, of Walsh-Hadamard transform and Haar transform [2] and the development of a large family of fast transforms with FFT-type algorithms [3¨C5]. Whereas Walsh-Hadamard and Haar transforms have already been known in mathematics, other transforms, for instance, quite popular at the time Slant Transform [6], were being invented ¡°from scratch.¡± This development was mainly driven by the needs of data compression, though the usefulness of transform domain processing for image restoration and enhancement was also recognized very soon [3]. This period ended up with the introduction of the Discrete Cosine Transform (DCT, [7, 8]), which was soon widely recognized as the best choice among all available at the time transforms and resulted in JPEG and MPEG standards for image, audio, and video compression. The third large wave of activities in transforms for signal and image processing was caused by the introduction, in the 1980s, of a family of transforms that was coined the name ¡°wavelet transform¡± [9]. The main motivation was achieving a better local representation of signals and images in contrast to the ¡°global¡± representation that is characteristic to Discrete Fourier, DCT, Walsh-Hadamard, and other fast transforms
%U http://www.hindawi.com/journals/aee/2014/276241/