Research On Image Compression Based On Wavelet Transform

With the rapid development of digital communications, computer networks and multimedia technologies, image compression has become one of the essential techniques in the information transmission system. Because of the characteristics, such as the high compression ratio, rapid compression, and maintaining the same basic features, image compression technology based on wavelet transform becomes an important branch, and is widely used in the field of image compression.A deep research on static image compression was presented in this paper. The theory of compression code algorithm based on the wavelet transform was described, and then wavelet lifting scheme and embedded zero-tree wavelet(EZW) algorithm are researched.The image compression technology based on wavelet threshold was improved. According to the function of wavelet threshold in image compression, and through setting a reasonable threshold, a good results was achieved. To improve the efficiency of the wavelet lifting scheme, selected the appropriate wavelet, adopted recursion algorithm in the process of coding and decoding and adopting wavelet lifting scheme based on integer , and then a rapid coding algorithm was achieved. An improved embedded zero-tree wavelet(EZW) encoding algorithm was given. Selected appropriate wavelet(CDF9-7), considered the decomposition levels as well as the principle of efficiency priority and combined with improved algorithm based on wavelet lifting scheme, an effective impression algorithm was achieved. The high-frequency and low-frequency coefficients were handled in different method in the realization of specific process. The test results indicate that improved algorithm has also been enhanced in image compression performance and image quality.The static images'compression method based on wavelet transform were proposed, but video images were not involved in this paper. The image compression based on wavelet transform image compression method is a very good method, there are many places worth further study.