idct2d.m

在matlab环境下实现dtc变换

function Y = idct2D (img)

Y = zeros(8,8);
tem = 0;

for x=1:8
    for y=1:8
        for u=1:8
            for v=1:8
                if (u==1 & v~=1)
                    tem =tem + (img(u,v)*cos((2*x-1)*(u-1)*pi/16)*cos((2*y-1)*(v-1)*pi/16)) / (4*sqrt(2));
        
                elseif (v==1 & u~=1)
                    tem =tem + (img(u,v)*cos((2*x-1)*(u-1)*pi/16)*cos((2*y-1)*(v-1)*pi/16)) / (4*sqrt(2));
        
                elseif (u==1 & v==1)
                    tem =tem + (img(u,v)*cos((2*x-1)*(u-1)*pi/16)*cos((2*y-1)*(v-1)*pi/16)) / 8;
        
                else
                    tem =tem + (img(u,v)*cos((2*x-1)*(u-1)*pi/16)*cos((2*y-1)*(v-1)*pi/16)) / 4;
                end;
                
                Y(x,y)= tem;
            end;
        end;
        tem = 0;
    end;
end;