Improved zero-tree coder research based on wavelet coefficients

By analyzing the characteristics of degree zerotree, both the EZW wavelet coder and SPIHT wavelet coder have advantages and disadvantages. Combined with the characteristics of wavelet coefficients, a zerotree based on hybrid encoder program was found. With the wavelet zerotree definition, taking the pre-processing zerotree before the zerotree coding, the identification of suitable programs of zerotree encoder comes out. The simulation results show that comparing with the separate use of EZW or SPIHT encoder, the hybrid encoder´s encoding algorithm can effectively enhance the efficiency of code compression PSNR.