The Implementation Of Quantization Coder For CCSDS Image Compression Algorithm

The Consultative Committee for Space Data System (CCSDS) data compression working group had adopted a recommendation for image data compression, with a final release in November 2005. Compared with current dominant image compression algorithms, such as, JPEG2000 and SPIHT, the CCSDS compression algorithm has new features, whose basic structure is composed of discrete wavelet transform (DWT) and bit plane encoder (BPE). DWT is implemented with 9/7 biorthogonal wavelet transform according with JPEG2000, however, the bit plane encoder is much easier than the EBCOT module in JPEG2000. Thus, CCSDS achieves lower complexity on the whole. In chapter 2, there is a brief description for SPIHT and JPEG2000 algorithms. The implementation of CCSDS algorithm is presented in chapter 3 in detail, and this paper puts an emphasis on the realization of quantization coder. Meanwhile, the performance of CCSDS algorithm is analyzed in varies aspects in chapter 4, including how to decide the wavelet level, whether the entropy encoding is necessary or not and the ability to correct the error bit. The comparison results with JPEG2000 and SPIHT algorithms are also showed in the end of this paper. Finally, we give the present status of CCSDS algorithm and its development in the future. From the experimental data we can see the advantages of CCSDS algorithm, that are, low complexity, easy to implement on software and hardware and good performance. In order to meet the requirement of fast and real-time image compression, the algorithm must be simple and convenient, low memory capacity and prone to implement on hardware. Concerning applications in space exploration, e.g, airborne shuffles, complexity and power are restricted to the working system. CCSDS is proposed to cater to the requirements above. CCSDS is more suitable to the applications of space exploring, compared with high complexity and cost in current JPEG2000 and SPIHT algorithm. Furthermore, image compression algorithms have been standardized which provide the basis of space application in the future.