【图像压缩】基于小波变换图像压缩含Matlab源码3.zip

%第一层小波分解 clc,clear load wbarb; image(X); colormap(map); colorbar; % 小波分解 [cA1,cH1,cV1,cD1] = dwt2(X,'bior3.7'); % 第一层小波逼近系数--cA1 % 水平系数--cH1 % 垂直系数--cV1 % 对角系数--cD1 A1 = upcoef2('a',cA1,'bior3.7',1); H1 = upcoef2('h',cH1,'bior3.7',1); V1 = upcoef2('v',cV1,'bior3.7',1); D1 = upcoef2('d',cD1,'bior3.7',1); %显示第一层小波分解图形 colormap(map); subplot(2,2,1); image(wcodemat(A1,192)); title('第一层小波逼近系数A1') subplot(2,2,2); image(wcodemat(H1,192)); title('第一层小波水平系数H1') subplot(2,2,3); image(wcodemat(V1,192)); title('第一层小波垂直系数V1') subplot(2,2,4); image(wcodemat(D1,192)); title('第一层小波对角系数D1') %% 由单层逆小波变换重新产生一副图像 % 逆变换 Xsyn = idwt2(cA1,cH1,cV1,cD1,'bior3.7'); %To perform a level 2 decomposition of the image [C,S] = wavedec2(X,2,'bior3.7'); %To extract the level 2 approximation coefficients from C cA2 = appcoef2(C,S,'bior3.7',2); %To extract the first- and second-level detail coefficients from C cH2 = detcoef2('h',C,S,2); cV2 = detcoef2('v',C,S,2); cD2 = detcoef2('d',C,S,2); cH1 = detcoef2('h',C,S,1); cV1 = detcoef2('v',C,S,1); cD1 = detcoef2('d',C,S,1); %To reconstruct the level 2 approximation from C A2 = wrcoef2('a',C,S,'bior3.7',2); %To reconstruct the level 1 and 2 details from C H1 = wrcoef2('h',C,S,'bior3.7',1); V1 = wrcoef2('v',C,S,'bior3.7',1); D1 = wrcoef2('d',C,S,'bior3.7',1); H2 = wrcoef2('h',C,S,'bior3.7',2); V2 = wrcoef2('v',C,S,'bior3.7',2); D2 = wrcoef2('d',C,S,'bior3.7',2); %To display the results of the level 2 decomposition colormap(map); subplot(2,4,1);image(wcodemat(A1,192)); title('第一层小波逼近系数A1') subplot(2,4,2);image(wcodemat(H1,192)); title('第一层小波水平系数H1') subplot(2,4,3);image(wcodemat(V1,192)); title('第一层小波垂直系数V1') subplot(2,4,4);image(wcodemat(D1,192)); title('D第一层小波对角系数D1') subplot(2,4,5);image(wcodemat(A2,192)); title('第二层小波逼近系数A2') subplot(2,4,6);image(wcodemat(H2,192)); title('第二层小波水平系数H2') subplot(2,4,7);image(wcodemat(V2,192)); title('第二层小波垂直系数V2') subplot(2,4,8);image(wcodemat(D2,192)); title('第二层小波对角系数D2') %% %% 重构 the original image from the wavelet decomposition structure X0 = waverec2(C,S,'bior3.7'); % 压缩图像X [thr,sorh,keepapp]= ddencmp('cmp','wv',X); % 降噪 or 压缩 using wavelets. [Xcomp,CXC,LXC,PERF0,PERFL2] = ... wdencmp('gbl',C,S,'bior3.7',2,thr,sorh,keepapp); % 对比查看压缩前后图像 colormap(map); subplot(121); image(X); title('原始图像'); axis square subplot(122); image(Xcomp); title('压缩图像'); axis square