说明：  实现JPEG的压缩和编码 （1）首先通过DCT变换去除数据冗余； （2）使用量化表对DCT系数进行量化； （3）对量化后的系数进行Huffman编码。
(The realization of JPEG compression and coding (1) First of all, through the DCT transform to remove data redundancy (2) the use of quantization table of quantization DCT coefficients (3) of the coefficients after quantization Huffman coding.)