小波分解-加噪声-去噪-重构-评价

X=imread('1.jpg');
X=imnoise(X,'salt & pepper',0.5);
img=double(rgb2gray(uint8(X)));
x_gray_double=img;
[m n]=size(img);
[LL LH HL HH]=haar_dwt2D(img);
img=[LL LH;HL HH];     
imgsplit1=[LL LH;HL HH]; 
imgn=zeros(m,n);
for i=0:m/2:m/2
    for j=0:n/2:n/2
        [LL LH HL HH]=haar_dwt2D(img(i+1:i+m/2,j+1:j+n/2));
        imgn(i+1:i+m/2,j+1:j+n/2)=[LL LH;HL HH];  
    end
end
wavelet='sym4';
[c,s]=wavedec2(X,2,wavelet);
a0= wrcoef2('a',c,s,wavelet,1);
%a2 = uint8(wrcoef2('a',c,s,'sym4',2));
[thr0, sorh, keepapp] = ddencmp('den', 'wv',X);
a=max(c)*0.15;
[a1, cxc, lxc, perf0, perf2] = wdencmp('gbl', c,s, wavelet, 2, a, sorh, keepapp);
figure(1)
subplot(231),imshow(uint8(X)),title('原始图像');axis square;
subplot(232),imshow(imgsplit1),title('一层分解');axis square;
subplot(233),imshow(imgn),title('二层分解');axis square;
subplot(234),imshow(uint8(a1)),title('重构');
a=uint8(round(X));
b=uint8(round(a1));
[PSNR, MSE MAE] = psnr(a, b)