function Rick=dctY(p,X)
[m,n]=size(X);n=m;
for i=2:n
    for j=1:n
        C(i,j)=sqrt(2/n)*cos((i-1)*(j-1/2)*pi/n);
    end
end
C(1,1:n)=ones(1,n)/sqrt(n);

Y=C*X*C';
Q=p*[16 11 10 16 24 40 51 61; 12 12 14 19 26 58 60 55; 14 13 16 24 40 57 69 56; 14 17 22 29 51 87 80 62; 18 22 37 56 68 109 103 77; 24 35 55 64 81 104 113 92; 49 64 78 87 103 121 120 101; 72 92 95 98 112 100 103 99]; 
Yq=round(Y./Q);

Ydq=Yq.*Q;
Xdq=C'*Ydq*C;
Rick=Xdq+128;
%Xf=uint8(Rick);
%imagesc(Xf);colormap(gray)


