what is matlab code for MSE and PSNR of 2 images?

Image Processing

Answer 1

[Image Analyst]

Try this:

thePSNR = psnr(testImage, referenceImage);
theMSE = immse(testImage, referenceImage);

[Aniruddha Rakshit]

does the function works for matlab 2011?

[Image Analyst]

No. Time to upgrade - it's been 5 years. Or see attached demo that works in antique versions.

[RAKESH KUCHANA]

clc;

x = imread('brain_mri(resized).png');

y = imread('brain_stego(resized).png');

Y1 = y;

[R,C] = size(Y1);

for i=2:R-1

for j=2:C-1

tmp = Y1(i-1:i+1, j-1:j+1);

if 0<Y1(i,j) && Y1(i,j)<255

Y1(i,j) = Y1(i,j);

else

b = sort(tmp(:));

b1 = b(b~=0);

b2 = b1(b1~=255);

b3 = mean(b2);

Y1(i,j) = b3;

end

end

end

subplot(1,3,1); imshow(x);

subplot(1,3,2); imshow(y);

subplot(1,3,3); imshow(Y1);

x = uint8(x);

y = uint8(y);

Y1 = uint8(Y1);

MXN = R*C;

MAE = (sum(sum(abs(((x)-(Y1))))))/MXN;

MSE = sum(sum(((x)-(Y1)).^2))/MXN;

PSNR = 10*log10(255^(2)/MSE);

gg = sum(sum(((double(y))-double(x))).^(2));

gg1 = sum(sum(((double(Y1))-double(x))).^(2));

IEF = gg./gg1;

val = ssim(Y1,x);

%Please verify this code, as I am getting error in bolded text line as "Matrix dimensions must agree & error in line 34". Solve this asap.

[Image Analyst]

Never use size() like that on an image. Always have 3 output arguments just in case it's color. See Steve's blog for more on the reason for that:

Too much information about the size function | Steve on Image Processing