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, using Sobel, Laplacian Gaussian method to extract the edge of a gray image