Video Compression Based On Wavelet Transform Analysis

What the image video compression solves is reducing the data amount as possible while showing digital images. Since the image coding theory was put forward 60 years age, great progress of image compression has been made and many corresponding standards have been exerted by international organizations. In recent years, a new mathematical branch developing from the classical harmonic analysis, wavelet transform, can decompose the images into low frequency components and high frequency components so that the images can be better analyzed and disposed. The diamonds effects caused by the traditional DCT transform can be removed by the wavelet transform. Wavelet transform has upstanding quality at time domain and frequency domain, which can effectively characterize signals.This paper analyzes the necessity and feasibility for images compression at first, and then makes a comparison and summarization for the traditional compression methods. The paper introduces simply wavelet transform and time-frequency analysis, elaborates 2-D wavelet transform and 2-D image multi-resolution analysis in detail, and makes some discussions on the wavelet bases selection in digital image compression. The paper studies thoroughly embedded zero tree wavelet coding which is very important in digital image compression coding methods.This paper designs the wavelet video image compressing system based on sub-block motion compensation. The fast searching method of multi sub-block motion vector is used in space-domain motion compensation, so the luminance images between frames concentrate mainly on low frequency and a lot of zeros appear on high frequency. Embedded zero tree wavelet transform encodes the luminance images between frames, so it can realize the efficient compensation of video image and get the good visual results in decoding image. The experiment results show that it is a feasible and efficient method.Finally the selection of chips and designs structures for the five units which composite the real-time video compression system are designed, and the software design for the compression system is also presented. The design scheme for real-time video compression system based on the special image processing chip ADV611 is described. So the system can finish real-time video compression well and compression rate is high and the reconstruction image is clear.