hufman coding. Input QUALITY determines the amount of information that is lost and compression achieved. Y is an encoding structure containing fields: Y.size Size of X Y.numblocks Number of 8-by-8 encoded blocks Y.qualit

应用哈夫曼编码实现对灰度图片的压缩（原图片应先转码为bmp格式）(The application of Huffman coding to compress the grayscale images (the original image should be transcoded to BMP format first))