Satellite image compression by concurrent representations of wavelet blocks

This paper proposes a complete compression and coding scheme for onboard satellite applications considering the main on-board constraints: low computational power and easy bit-rate control. The proposed coding scheme improves the performance of the current CCSDS recommendation (Consultative Committee for Space Data Systems) for a low additional complexity. We consider post-transforms in the wavelet domain, select the best representation for each block of wavelet coefficients, and encode it into an embedded bit stream. After applying a classical wavelet transform of the image, several concurrent representations of blocks of wavelet coefficients are generated. The best representations are then selected according to a rate-distortion criterion. Finally, a specific bit-plane encoder derived from the CCSDS recommendation produces an embedded bit stream ensuring the easy rate control required. In this article, both the post-transforms and the best representation selection have been adapted to the low complexity constraint and the CCSDS coder has been modified to compress post-transformed representations.