Research Of Still Image Compression Based On Embedded Zero-tree Coding

With the age of information coming, the research of image coding method has become one of the most active fields in information technology by way of computer communication, information store, Internet communication technology, etc. Especially in 21st century, with the development of electronic and communicate technology, it is possible to realize the Video telephone, meeting TV, signal TV, information high way etc. On this occasion, it inevitably becomes one of the main tasks to seek after the effective image coding method, and it will become one hot point of research at home and abroad.The paper can be divided into six parts. Firstly, the background and significance of our research is introduced. Secondly, summarization of image compression technology and developments at home and abroad are discussed. Thirdly, based on the theories of wavelet transform in image compression, and with lots of experiments, the characteristics of wavelet coefficients are analyzed and the advantage of why wavelet transform is applied for image coding are discussed. Then, combined with quantization of different sub-band wavelet coefficients, and through experiments analysis on sub-band coefficients and lever decomposition and method of quantization, the project is designed, which is propitious to improving image compression quality and coding efficiency. At the same time, with the analysis on distribution of transform coefficients and the advantage and shortage of the traditional EZW algorithm, an advanced wavelet zero-tree coding algorithm of image compression is developed, which is based on implementing the EZW algorithm. In addition, some experiment results are given to testify the efficiency of the EZW algorithm objectively and subjectively. At last, the structure of the JPEG 2000 image compression standard is analyzed, and the algorithm of JPEG 2000 is discussed. Through compared JPEG 2000 with JPEG and compared JPEG 2000 with EZW algorithm and the advanced algorithm, the conclusion is drawn eventually, which is the advanced algorithm that is put forward by the paper may improve the efficiency of image compression exactly.