霍夫曼编码；量化到8位字节每个像素编码及解码(Write a MATLAB function [zipped, info] = pixel_coder(X) that takes an image X and using the Huffman coder above applied in the pixel domain quantized to 8 bits per pixel returns the coded sequence zipped along with the header

用MATLAB实现JPEG2000压缩，用霍夫曼编码解码，实现压缩