sparse matrix compression
based on encoding techniques described in "Layerwise Sparse Coding for Pruned Deep Neural Networks with Extreme Compression Ratio" https://cs.nju.edu.cn/rl/people/liwb/AAAI20b.pdf
based on encoding techniques described in "Layerwise Sparse Coding for Pruned Deep Neural Networks with Extreme Compression Ratio" https://cs.nju.edu.cn/rl/people/liwb/AAAI20b.pdf