calculating PSNR

I have two images original image and compressed image,please tell how to calculate mean square error and psnr

Answer 1

[Image Analyst]

Did you see the formula at http://en.wikipedia.org/wiki/PSNR? Of course you can just subtract the images and use the sum() function instead of the loops, which I know you know how to do. Just make sure you use .^2 instead of ^2 because you want an element-by-element squaring. Give it a try - it's just one line of code.

[kash]

[M N] = size(origImg);

error = origImg - compImg;

MSE = sum(sum(error .* error)) / (M * N);

is it corect Mr.Analyst

[Image Analyst]

Looks like it should be as long as origImg & compImg are floating point images and not uint8 or uint16. I was thinking of something like

MSE = mean2((single(image1) - single(image2)).^2);

[kash]

Thanks MR.Analyst

Answer 2

[Wayne King]

The Wavelet Toolbox has a function for this, measerr()

>>doc measerr

[kash]

Wayne i am getting page not found,am using 2010a

[Wayne King]

introduced in R2010b