中文说明：
matlab的图像处理。图像编码（HUFFMAN编码）小波变换，1、 分别用sobel、Laplacian-Gaussian方法对一幅灰度图像进行边缘提取。
English Description：
MATLAB image processing. Image coding (Huffman coding) wavelet transform, 1 Sobel and Laplacian Gaussian methods are used to extract the edge of a gray image