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Image Compression Coding Method On Integer To Integer Wavelet Transform

Posted on:2005-09-25Degree:MasterType:Thesis
Country:ChinaCandidate:D SuFull Text:PDF
GTID:2168360125463860Subject:Signal and Information Processing
Abstract/Summary:PDF Full Text Request
Although the techniques of data storage are developing and the band of channel is wider than past, the demand for compression for image data is rapidly growing so that to save the space of storage and improve the use ratio of channel. Comparing with lossy image compression, the lossless image compression is more difficult and its development is slower. Now, image compression method based on wavelet is the branch which development is fast in image compressing field. Lifting scheme can design the wavelet transforms that map integer to integer, which provides the effective tool for studying the lossless image compression. On the other hand, the method for wavelet coefficients coding is a key technique to implement image compression, which not only affects the effect of compression, but also the qualities of resuming image and the time of coding and decoding.This thesis presents an investigation into lifting scheme, which is new method of the second generation wavelet. It not only inherits the characteristic of the first generation wavelet, but is independent of Fourier transform and particularly easy to build on non linear wavelet transforms, such as integer wavelet transforms. This thesis introduces the theory of lifting and its key techniques, especially, analyzing the whole process for factoring the wavelet transform into lifting steps. Then, the 9/7-F, 9/7-M and 5/3 wavelets which use generally in image compression, are selected for factoring them into lifting steps so as to study the coefficients coding.The method based on scalar quantized significane testing schemes is an important class of coding for wavelet coefficients, which characters are low complication, good performance, and so on. Algorithms, such as the Embedded Zerotree Wavelet algorithm(EZW), Compression with Reversible Embedded Wavelets(CREW), Set Partitioning In Hierarchical Trees(SPIHT), the Set Partition Embedded bloCK coder(SPECK), which are classical algorithms based on wavelet for image compression, are belong to this type method, which is studied in this thesis so as to find the way to improve the performance of lossless image compression. These works are the key of this thesis. An investigation of two classical algorithms, SPIHT and SPECK, is presented. Then, this thesis presents an algorithm based on the method for lossless image compression, which uses new strategy of set partitioning and other new methods, which improve the performance of lossless image compression and not affect the lossy compression. The new algorithm comparing with SPIHT and SPECK has better performances in lossless compression, lossy compression and time of coding and decoding. In addition, this thesis presents an investigation into arithmetic coding, especially its implementation. This is for finding the other way to improve the performances of the new algorithm. This thought is proved by the practice.
Keywords/Search Tags:Image compressing, Coding, Wavelet, Lifting scheme, SPIHT, SPECK, Arithmetic coding
PDF Full Text Request
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