Research And Implementation Of Image Coding Based On Wavelet Theory

The size of raw digital image file is too large to be storeed, transferred and processed. It is necessary to compress it into a compact format. The key technology of image compression is to transform the image data, to quantify the transformed data and to code the quantified data. Wavelet image coding has become a prospective image compression method with the fast development of wavelet analysis in recent years.Image compression methods based on wavelet theory are researched in this paper. First, the general situation of still image coding and the method of wavelet image coding are introduced. Second, the embedded zerotree wavelet (EZW) algorithm is discussed and some improvement is made to it. Third, further to above-mentioned improvements, a new algorithm based on zerotree wavelet and code transform is presented. Compared with the traditional embedded zerotree wavelet algorithm, the new algorithm can compress images with more higher-quality reconstructed image and less computation complexity. The experimental results are satisfying.Embedded system is a specific application computer system that focuses on the application. It is based on the computer technology, and its hardware and software is customer reconfigurable. The development of embedded systems is very fast during the last ten years. By the progress of the networks technology, the embedded system combined with networks communication technology will be very important now and the future.Therefore, in this background, the thesis chooses the image processing chip Clarity4 which based on embedded processor ARM as the core hardware platform, developing an embedded hardware implement of image compression with the support of the embedding Necleus PLUS operating system and loading standard image processing software.