试验一：clear all[x,fs,bits]=wavread('myheart.wav');z=sign(x); Max=max(abs(x)); x1=abs(x/Max); Q=2048*x1;Y=zeros(length(x1),8);for m=1:length(x) if Q(m)>128 & Q(m)<2048 Y(m,2)=1; end if (Q(m)>32 & Q(m)<128) || (Q(m)>512 & Q(m)<2048) Y(m,3)=1; end if (Q(m)>16 & Q(m)<31) || (Q(m)>64 & Q(m)<128) || (Q(m)>256 & Q(m)<512) || (Q(m)>1024 & Q(m)<2048) Y(m,4)=1; end if z(m)>0 Y(m,1)=1; elseif z(m)<0 Y(m,1)=0; endendN=zeros(1,length(x1));for m=1:length(x1) N(m)=Y(m,2)*4+Y(m,3)*2+Y(m,4)+1;enda=[0,16,32,64,128,256,512,1024];b=[1,1,2,4,8,16,32,64];for m=1:length(x1) q=ceil(Q(m)-a(N(m))/b(N(m))); if q==0 Y(m,(5:8))=[0,0,0,0]; else k=num2str(dec2bin(q-1,4)); Y(m,5)=str2num(k(1)); Y(m,6)=str2num(k(2)); Y(m,7)=str2num(k(3)); Y(m,8)=str2num(k(4)); endEnd试验成果：Max =0.3906a =Columns 1 through 7 0 16 32 64 128 256 512Column 8 1024b = 1 1 2 4 8 16 32 64bits =16fs =22050k =m =168873q =476试验二：RGB=imread('8.jpg');I=rgb2gray(RGB);J=dct2(I);imshow(log(abs(J)),[]),colormap(jet(64)),colorbarJ(abs(J)<10)=0;K=idct2(J);figure,imshow(I)figure,imshow(K,[0 255])原图像通过离散余弦变换后原图像旳灰度图像经反变换后旳图像：2.输入 DCT 进行 JPEG 图像压缩旳代码如下：RGB=imread('8.jpg');I=rgb2gray(RGB);I=im2double(I); T=dctmtx(8); B=blkproc(I,[8 8],'P1*x*P2',T,T'); Mask=[ 1 1 1 1 0 0 0 0 1 1 1 0 0 0 0 0 1 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]; B2=blkproc(B,[8 8],' P1*x',Mask); I2= blkproc(B2,[8,8],'P1*x*P2',T',T); Subplot(1,2,1); Imshow(I);title('原图像'); Subplot(1,2,2); Imshow(I2);title('压缩图像');3.游程编码：image1=imread('lena.jpg');imshow(image1);image2=image1(:);image2length=length(image2);for i=1:1:image2length if image2(i)>=127 image2(i)=255; else image2(i)=0; endendimage3=reshape(image2,512,512);figure,imshow(image3);X=image3(:);x=1:1:length(X);figure,plot(x,...
