Modified SPIHT Based Image Compression Algorithm for Hardware Implementation

Among all wavelet transform and zero-tree quantization based image coding algorithms, set partitioning in hierarchical trees (SPIHT) is well known for its simplicity and efficiency. However, the use of three lists causes a high, variable and data dependant memory requirement, therefore the original SPIHT dose not suit for hardware implementation. In this paper, a Modified SPIHT (MSPIHT) method suitable for image compression´s hardware implementation is proposed. Through using two state mark bitmaps to replace three lists of SPIHT, MSPIHT saves memory space and avoids memory dynamic management. Furthermore according to using an array to store the maximum value of zerotree set´s coefficients as well as merging the sorting pass and refinement pass as one scan, MSPIHT also enhances the algorithm´s iteration efficiency. Experimental results show that this MSPIHT quantization method is simple, efficient, resource saving, and is suitable for real time and low memory implementation.