说明：  本代码由matlab语言编写，实现了jpeg算法，主要为了说明基本的JPEG功能。经过DCT变化，量化，进行DPCM编码，然后之字形扫描AC系数，进行行程（LZW）编码。 显示原始图象和经编码解码后的图象，显示压缩比，并计算均方根误差。
(The code consists of matlab language, to achieve a jpeg algorithm, mainly to illustrate the basic functionality of JPEG. After changing DCT, quantization, for DPCM coding, then the AC coefficients of the zigzag scanning, for stroke (LZW) coded. Shows the original image and the encoded decoded image showing the compression ratio, and calculate the mean square error.)