Lossless compression of full-surface solar magnetic field image based on huffman coding

With the development of astronomical research, more and more space telescope satellites will be launched in the future. High quality space telescope images would definitely cause huge amount of data sent back. Because of the limited satellite data transmission resources, images' lossless compression on satellite is imperative. Huffman coding is a lossless compression algorithm which pursues the best coding based on the probability of characters. In this paper, Huffman coding algorithm is combined with several preprocessing methods to compress the full-surface solar magnetic field image, and the compression ratio can maximally achieve 40% higher than non-preprocessing.