Application Of Wavelet Transform In Digital Video Image Compression And Coding

The wavelet technology, which developed on the base of Fourier analysis,offers a self-adaptive localization analysis method for a given signal in bothtime domain and frequency domain. Through extension and translationoptions and multi-scale analysis, it can extract helpful signal informationeffectively from signal, special no steady signal, so wavelet technology hasbecome a powerful tool for digital image processing and compression and hasbeen hot point studied in recent years.This paper analyzes the necessity and feasibility for images compressionat first, and then makes a comparison and summarization for the traditionalcompression methods. The paper introduces simply wavelet transform andtime-frequency analysis, elaborates 2-D wavelet transform and 2-D imagemulti-resolution analysis in detail, and makes some discussions on the waveletbases selection in digital image compression, which includes the performanceanalysis and evaluation criteria of wavelet bases. The paper studies thoroughlyembedded zero tree wavelet coding which is very important in digital imagecompression coding methods, and displays the experiment results.This paper designs the wavelet video image compressing system basedon sub-block motion compensation. The fast searching method ofmulti-sub-block motion vector is used in space-domain motion compensation,so the luminance images between frames concentrate mainly on low frequencyand a lot of zeros appear on high frequency. Embedded zero tree wavelettransform encodes the luminance images between frames, so it can realize theefficient compensation of video image and get the good visual results indecoding image. The experiment results show that it is a feasible and efficientmethod.At last, the selection of chips and designs structures for the five unitswhich composite the real-time video compression system are designed, andthe software design for the compression system is also presented. The designscheme for real-time video compression system based on the special imageprocessing chip—ADV601LC is described. So the system can finish real-timevideo compression well and compression rate is high and the reconstructionimage is clear.