利用Matlab编程实现对lena.bmp灰度图象进行QF=50和QF=40的压缩和解压缩，比较二者的PSNR，并且利用霍夫曼编码模拟信道中传输图象。通过了Matlab2009A测试。-Using Matlab program to compress and decompress the gray image Lena.bmp at QF = 50 and QF = 40,as well as comparing the result of two situation.Then using Huffman coding analog channels transmitted images. Adopted Matlab2009A test.