x=imread('mj.jpg');
x=double(x);
r=x(:,:,1);g=x(:,:,2);b=x(:,:,3);
xgray=0.2126*r+0.7152*g+0.0722*b;
xb=xgray(381:388,181:188);
xd=double(xb);
xc=xd-128;
y=dct(dct(xc')');
p=1;
q=p*8./hilb(8);
yq=round(y./q);
yq
xd=double(xb);
xc=xd-128;
y=dct(dct(xc')');
p=2;
q=p*8./hilb(8);
yq=round(y./q);
yq
xd=double(xb);
xc=xd-128;
y=dct(dct(xc')');
p=4;
q=p*8./hilb(8);
yq=round(y./q);
yq
xd=double(xb);
xc=xd-128;
y=dct(dct(xc')');
p=10;
q=p*8./hilb(8);
yq=round(y./q);
yq
yq =
13 9 1 0 1 0 0 0
37 -4 -1 -1 0 0 0 0
-4 -6 -1 2 0 0 1 0
-2 4 2 1 -1 0 0 -1
0 1 -1 -2 0 1 0 0
0 -1 0 0 1 0 0 1
1 0 1 1 0 -1 0 0
-1 0 -1 0 -1 1 0 -1
yq =
7 5 1 0 0 0 0 0
18 -2 -1 -1 0 0 0 0
-2 -3 -1 1 0 0 0 0
-1 2 1 0 0 0 0 0
0 1 -1 -1 0 0 0 0
0 -1 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
yq =
3 2 0 0 0 0 0 0
9 -1 0 0 0 0 0 0
-1 -1 0 0 0 0 0 0
-1 1 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
yq =
1 1 0 0 0 0 0 0
4 0 0 0 0 0 0 0
0 -1 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0