Wavelet-based contourlet coding using SPECK algorithm

We proposed a new still image compression algorithm called CSPECK which was constructed by the wavelet-based contourlet transform (WBCT) and set partitioning embedded block coding (SPECK). In the WBCT, the high frequency sub-band decomposed by the wavelet transform was further decomposed into multiple directional sub-bands by directional filter bank so as to explain the edge and texture of the image more sparsely. The SPECK algorithm exhibits lower complexity and more efficient compression ratio than SPIHT based on WBCT. Experimental results demonstrate that the proposed method is efficient in coding images that possess mostly textures and contours. The simulation results also show that this new coding algorithm increases the PSNR over CSPIHT.