Matlab Code For DCT-IDCT

i=imread('cameraman.tif');

[r c]=size(i);

ID=double(i);

if(r==c)

    N=c;

else

    error('Error');

end

for u=0:N-1

    for v=0:N-1

        if(u==0)

            c(u+1,v+1)=sqrt(1/N);

        else

            c(u+1,v+1)=sqrt(2/N)*cos(((2*v+1)*pi*u)/(2*N));

        end

    end

end

dct2=c*ID*(c');

subplot(1,3,1);

imshow(i);

title('Original image');

subplot(1,3,2);

imshow(uint8(dct2));

title('DCT of image');

dct2_inv=(c')*dct2*c;

subplot(1,3,3);

imshow(uint8(dct2_inv));

title('IDCT of image');