how can i write the code line for comparing two images that one image is 90% similar to another image

how can i write the code line for comparing two images that one image is 90% similar to another image

Answer 1

[Image Analyst]

Sounds like you already have that code. How did you get your 90% number?

There are a number of ways for determining how close images are to each other. PSNR is often used in compression studies. SSIM is often used in CBIR. There are others also. You can find these definitions and terms in Wikipedia or Google. Look for code in the File Exchange.

Answer 2

[Bob]

Your question is quite vague but from what i understand, it seems like you're gonna need correlation (corr2) for this i.e.

corr2(i,j);

[Image Analyst]

Correlation won't do it. You can sometimes have a higher correlation for two different images than for the same image with itself. If you want to go the correlation route, you'd have to use normalized cross correlation, performed by normxcorr2() in the Image Processing Toolbox. I've posted demos using it here before - search for it if you're interested.