Researches of an Image Compression Algorithm Based on Improved Zerotree Wavelet

Nowadays,most image compression techniques exploit the dependencies between subbands in a wavelet transformed image.This paper adopts the biorthogonal lifted wavelet to transform images into wavelet field.Based on the biorthogonal wavelet,a progressive augmented zerotree image coding algorithm is put forward by adding symbols of entropy encoding.Both the coder and decoder require to maintain only one list,and it has no sorting operation.Experimental results show that this method can compress image more efficiently with high compression ratio.