Embedded Zerotree Wavelet Image Compression Encoding Algorithm Research And Improvement

The purpose of this thesis is to improve the property of embedded zero-tree image compression coding algorithm in wavelet transform domain. In this paper, an improved Zero-tree coding method based on wavelet transform is proposed. The experiment results show the improvement is valid and high compression rate can be achieved.In recent years, the research of image coding method, which is the key technology of communication, medium store, multimedia computer technology, etc, has become one of the most active fields in information technology. Especially in 21st century, with the development of electronic and communicate technology, it is possible to realize the video telephone, meeting TV, digital TV, multimedia computer, information high way and etc. It will undoubtedly become one of the main tasks and international recognized hotspots to study the effective image compression coding method under this background.This paper includes five parts: 1.Introduced the background and significance of the thesis. 2. Introduced the basic knowledge of digital image compression, the international image compression stands and the development of the image compression technology. 3. Analyzed the features of wavelet coefficients of the image based on the theories of wavelet transform, and discussed the advantages for image compression coding. 4. Discussed the basic theories, implement method and advantages of embedded zero-tree wavelet algorithm. 5. Research the disadvantages of traditional EZW algorithm, then put forward the improved image compression method, and analyzed the experimental results.The improved algorithm consists of three parts.Choosed the more suitable Z97 biorthogonal wavelet basis for the image transform. Used symmetric periodic extension method to solve the boundary problem and improve the compression quality.Modified the quantization threshold with the visual model according to the...