infile='aish.jpg';
if (exist(infile)==2)
a = imread(infile);
figure('Name','Input image');
imshow(a);
else
warndlg('The file does not exist.',' Warning ');
im=[];
return
end
if isrgb(a)
if isa(a(:,:,1),'uint8')
red = double(a(:,:,1));
green = double(a(:,:,2));
blue = double(a(:,:,3));
red_dct=dct2(red);
green_dct=dct2(green);
blue_dct=dct2(blue);
red_pow = red_dct.^2;
green_pow = green_dct.^2;
blue_pow = blue_dct.^2;
red_pow=red_pow(:);
green_pow=green_pow(:);
blue_pow=blue_pow(:);
[B_r,index_r]=sort(red_pow);
[B_g,index_g]=sort(green_pow);
[B_b,index_b]=sort(blue_pow);
index_r=flipud(index_r);
index_g=flipud(index_g);
index_b=flipud(index_b);
im_dct_r=zeros(size(red));
im_dct_g=zeros(size(green));
im_dct_b=zeros(size(blue));
coeff=25000;
for ii=1:coeff
im_dct_r(index_r(ii))=red_dct(index_r(ii));
im_dct_g(index_g(ii))=green_dct(index_g(ii));
im_dct_b(index_b(ii))=blue_dct(index_b(ii));
end
im_r=idct2(im_dct_r);
im_g=idct2(im_dct_g);
im_b=idct2(im_dct_b);
im=zeros(size(red,1),size(red,2),3);
im(:,:,1)=im_r;
im(:,:,2)=im_g;
im(:,:,3)=im_b;
im=uint8(im);
outfile='aish2.jpg';
imwrite(im, outfile);
figure('Name','Output image');
imshow(im);
return;
end
if isa(a(:,:,1),'uint6')
red = double(a(:,:,1));
green = double(a(:,:,2));
blue = double(a(:,:,3));
red_dct=dct2(red);
green_dct=dct2(green);
blue_dct=dct2(blue);
red_pow = red_dct.^2;
green_pow = green_dct.^2;
blue_pow = blue_dct.^2;
red_pow=red_pow(:);
green_pow=green_pow(:);
blue_pow=blue_pow(:);
[B_r,index_r]=sort(red_pow);
[B_g,index_g]=sort(green_pow);
[B_b,index_b]=sort(blue_pow);
index_r=flipud(index_r);
index_g=flipud(index_g);
index_b=flipud(index_b);
im_dct_r=zeros(size(red));
im_dct_g=zeros(size(green));
im_dct_b=zeros(size(blue));
for ii=1:coeff
im_dct_r(index_r(ii))=red_dct(index_r(ii));
im_dct_g(index_g(ii))=green_dct(index_g(ii));
im_dct_b(index_b(ii))=blue_dct(index_b(ii));
end
im_r=idct2(im_dct_r);
im_g=idct2(im_dct_g);
im_b=idct2(im_dct_b);
im=zeros(size(red,1),size(red,2),3);
im(:,:,1)=im_r;
im(:,:,2)=im_g;
im(:,:,3)=im_b;
im=uint16(im);
imwrite(im, outfile);
figure('Name','Output image');
imshow(im);
return;
end
if isa(a(:,:,1),'double')
red = double(a(:,:,1));
green = double(a(:,:,2));
blue = double(a(:,:,3));
red_dct=dct2(red);
green_dct=dct2(green);
blue_dct=dct2(blue);
red_pow = red_dct.^2;
green_pow = green_dct.^2;
blue_pow = blue_dct.^2;
red_pow=red_pow(:);
green_pow=green_pow(:);
blue_pow=blue_pow(:);
[B_r,index_r]=sort(red_pow);
[B_g,index_g]=sort(green_pow);
[B_b,index_b]=sort(blue_pow);
index_r=flipud(index_r);
index_g=flipud(index_g);
index_b=flipud(index_b);
im_dct_r=zeros(size(red));
im_dct_g=zeros(size(green));
im_dct_b=zeros(size(blue));
for ii=1:coeff
im_dct_r(index_r(ii))=red_dct(index_r(ii));
im_dct_g(index_g(ii))=green_dct(index_g(ii));
im_dct_b(index_b(ii))=blue_dct(index_b(ii));
end
im_r=idct2(im_dct_r);
im_g=idct2(im_dct_g);
im_b=idct2(im_dct_b);
im=zeros(size(red,1),size(red,2),3);
im(:,:,1)=im_r;
im(:,:,2)=im_g;
im(:,:,3)=im_b;
imwrite(im, outfile);
figure('Name','Output image');
imshow(im);
return;
end
end
if isgray(a)
dvalue=double(a);
if isa(a,'uint8')
img_dct=dct2(dvalue);
img_pow=(img_dct).^2;
img_pow=img_pow(:);
[B,index]=sort(img_pow);
B=flipud(B);
index=flipud(index);
compressed_dct=zeros(size(dvalue));
for ii=1:coeff
compressed_dct(index(ii))=img_dct(index(ii));
end
im=idct2(compressed_dct);
im=uint8(im);
end
if isa(a,'uint16')
img_dct=dct2(dvalue);
img_pow=(img_dct).^2;
img_pow=img_pow(:);
[B,index]=sort(img_pow);
B=flipud(B);
index=flipud(index);
compressed_dct=zeros(size(dvalue));
for ii=1:coeff
compressed_dct(index(ii))=img_dct(index(ii));
end
im=idct2(compressed_dct);
im=uint16(im);
end
if isa(a,'double')
img_dct=dct2(dvalue);
img_pow=(img_dct).^2;
img_pow=img_pow(:);
[B,index]=sort(img_pow);
B=flipud(B);
index=flipud(index);
compressed_dct=zeros(size(dvalue));
for ii=1:coeff
compressed_dct=zeros(size(dvalue));
end
im=idct2(compressed_dct);
end
imwrite(im, outfile);
figure('Name','Output image');
imshow(im);
return;
end
Posts
0 comments:
Post a Comment