Algorithm Research On Image Compression Based On Wavelet-based Contourlet Transform

With the rapid development of information technology, higher demands wereput on the image. Image resolution’s increase lead to a sharp increase in image data,this presents a greater challenge to image storage and transmission. Therefore, imagecompression and application market has a wide range of applications.WBCT transform (Wavelet-based Contourlet transform) is a newmulti-resolution, localized, multidirectional image representation. It will replaceLaplacian pyramid decomposition, the first step of Contourlet transform, withwavelet transform to eliminates the redundancy in LP decomposition. The secondstep of WBCT is using filter bank to realize multi-directional filter decomposition.This paper analyzes the image compression technology’s current situation bothat home and abroad and future development trends, and studied Wavelet transformtheory and Contourlet transform theory. Respectively, research for imagecompression algorithm based on wavelet transform and WBCT research andcomparative analysis of the compression of both.Main work and innovation are the following several points:First of all, I analyzed about the principles, the basic process of imagecompression, as well as some fundamental algorithm.Secondly, the paper analysis wavelet transform theory, detailed study of theprinciple and realization of two-dimensional orthogonal Wavelet transformalgorithms. Study of image compression algorithm based on wavelet transform,including EZW algorithm and SPIHT algorithm, and studied their implementationsteps.Thirdly, the basic theory and design of Contourlet transform was analyzed, andfound that it didn’t apply to image compression based on its feature, then WBCTwas submitted. Detailed study image compression based on WBCT and SPIHTalgorithm, we provide detailed implementation steps. As WBCT could express theimage outline better than wavelet transform, so the algorithm can preferablerepresent the image edge detail, highlighting images of important information.Finally, the characteristics of two different algorithms were studied and analysis.Using MATLAB simulation, we can compare the experimental results, and analysis the two algorithms’ advantages and disadvantages from subjective fidelity andobjective fidelity. Experimental results show that the algorithm presented in thisarticle, comparing EZW and SPIHT, it raises the compression ratio, as well as betterquality of reconstruction.