how can I compare two image after some changes?

HI, I want to compare two image and show the difference between them by a number. how can I do it? I want to normalize this difference. both images have same size, for example first image is the original image and second image is the original image after jpeg attack. using norm function is it true?

Answer 1

[Vandana Rajan]

Hi,

To measure quality of lossy image compression techniques like JPEG, you may use PSNR (Peak Signal to noise ratio).

https://en.wikipedia.org/wiki/Peak_signal-to-noise_ratio

https://in.mathworks.com/help/images/ref/psnr.html

https://in.mathworks.com/help/images/image-quality-metrics.html