Application Of Wavelet Transform In The Image Compression

Image compression technology is one of the key points in modern multimedia and communication area, at present, There are many types of compression technologies. Wavelet transform has been become a new signal analysis tool, because of overcoming the Fourier's limitation and having features of good time-frequency adaptive and multi-resolution analysis. Wavelet transform has been quickly developed and deeply applied. At present, EZW is one of efficacious algorithms It can improve image coding efficiency by analyzing and forming the modulus of wavelet transform.First, we summarize the necessary and work, discuss the theory of wavelet transform and concept especially, elaborating the theory of multi-resolution analysis and Mallat's fast algorithm, in the end introducing several classical image coding technology.Second, by discussing and analyzing the characteristic of image compression based on wavelet transform, We study the measures and several questions through wavelet transform.Final, we minutely analyze and discuss the algorithm encoded zero-tree wavelet. Thinking of its shortcoming, for example it was not fully use the characteristic of wavelet transform, human visual system, it will reduce the Gibbs phenomenon to some extent, which occurs in regenerated image edge and as well, A improved algorithm has been used. By examining the image edge, we can distinguish the high frequency noises and various directions. Finally zero-trees have been categorized and it have been coded.