Embedded Wavelet Image Coding Algorithm

With the development of modern communication technology, the more category anddata of transmitted image information are, the more society benefit and economy benefitof digital image compression are. Aiming at the coding algorithms of digital image, wehave researched, analyzed and improved them in this paper. Though wavelet coding hasacquired distinguished success in image coding field, many problems still need to besettled. This paper does the research on how to make the best of wavelet character forhigh-powered coding, how to reduce the complexity of a VISI implementation, and howto cut down the memory resource of operation, for these problems, we pat forwardeffective settled method. Therefore, the research is not only has theoretic meaning, butalso has practical value.This paper can be divided into five parts. First, the background and significance ofour research are introduced, together with the developing actuality in this field. Secondly,the main coding methods in image compression field and some internationalstandardization for still image are discussed. Then, then basic theories of wavelettransform and some classical wavelet image coding are described. In the following forthchapter, aiming at one of the most advanced wavelet-based and embedded image codingalgorithms nowadays, an improved coding algorithm is presented and completed. Theimproved SPECK algorithm not only includes all advantages of original SPECK, but alsoreduces the complexity of SPECK and improves the work efficiency of SPECK byadjusting the coding order of blocks and so on. Finally, the analysis of experimentalresults is shown. In the final chapter, aiming at LZC coding algorithm, a wavelet-basedand embedded algorithm for image coding, which uses no list during encoding anddecoding and easy for a VLSI implementation, an improved LZC algorithm is presentedand completed. The improved coding not only includes the advantage of original LZC,but also improves the work efficiency of LZC and reduces the complexity of LZC bychanging the coding order of spatial subbands and so on. Finally, the analysis ofexperimental results is shown. The experimental results show that our two proposedcoding algorithm not only have the properties of good vision effect, non-square effectand no edge oscillation, but also have better performance than that of two original codingalgorithms respectively in the aspects of the quality of image reconstruction and PSNR on the basic of same ratio of compression, Two coding algorithms presented by us in thispaper can be applied in many image compression fields.