Block Reordering Wavelet Packet

SPIHT Image Coding

Abstract 

        The set partitioning in hierarchical trees (SPIHT) coding algorithm, proposed by Said and Pearlman, provides effective progressive and embedding property. However, for images with high energy that is randomly dispersed throughout high frequency subbands in the wavelet domain, the SPIHT does not fully exploit energy compaction of the wavelet transform and thus becomes less efficient to represent these images. This paper presents an energy compaction method, block reordering wavelet packet SPIHT (BRWP-SPIHT) coding, to enhance the image visual quality. The block reordering technique divides the wavelet coefficients into blocks and reorders these blocks based on the significance of each block. The simulation results show that BRWP-SPIHT is superior, on average, to SPIHT by 0.6 dB for texture rich images. Subjectively, it also shows significant enhancement to the quality of the reconstructed image, particularly for images with fractal and oscillatory patterns.