An improved fast parallel SPIHT algorithm and its FPGA implementation

In view of the current stringent need to the real-time compression algorithm of the high-speed and high-resolution image, such as remote sensing or medical image and so on, in this paper, No List SPIHT (NLS) algorithm has been improved, and a fast parallel SPIHT algorithm is proposed, which is suitable to implement with FPGA. It can deal with all bit-planes simultaneously, and process in the speed of 4pixels/period, so the encoding time is only relative to the image resolution. The experimental results show that, the processing capacity can achieve 200MPixels/s, when the input clock is 50MHz, the system of this paper need 2.29ms to complete lossless compression of a 512×512×8bit image, and only requires 1.31ms in the optimal state. The improved algorithm keeps the high SNR unchanged, increases the speed greatly and reduces the size of the needed storage space. It can implement lossless or lossy compression, and the compression ratio can be controlled. It could be widely used in the field of the high-speed and high-resolution image compression.