Research On The Image Compression Coding Of The Embedded Zerotree Wavelet Based On Wavelet Transform

Digital image compression is the key technology of different kinds of applications in digital image processing. In the past years, great processes have been made in digital image compression area. Digital image compression based on wavelet transform is becoming one of the most important trends of development in this field because of wavelet transform's excellent performance both in time and frequency domain. With the development of technology, more and more algorithms emerge and their capability of real-time processing is attracting more focus than ever before.The wavelet transform have a better partial and space-frequency characteristics,an ability of describing the non-stationary image signal and a good function of adapting to the eye sense of visual characteristic. So it is extensively researched and applied in higher compression ratio of image coding field. The core of International Standard JPEG 2000 is based on the wavelet transform.EZW algorithm is the landmark in the research of wavelet image coding. It has been researched that EZW needs further improvement. In the thesis, after having introduced the theories about image coding and wavelet transform, then, the multiresolution analysis technology and the Mallat algorithm are introduced. And then the embedded wavelet zero-tree image coding (EZW) algorithm is discussed and analysed in detail. Based on the clear analysis, an improved algorithm is proposed in this thesis.The original and improved EZW algorithms simulated and their performances were compared. The improvement was proved to be efficient through the comparison between the data and the vision.