similarity between 2 B/w images?

Hi All

I have 2 B/W images , and i need to measure similarity between them , so for example if i use corr2 function:

I1=imread(............);
I2=imread(............);
x=corr2(I1,I2);

i find x=0.103931820103397

As i know that x represent the correlation coefficient , is it means similarity measure between I1,I2 or not ? is there anything must be added to find similarity between I1&I2, because I1&I2 are very similar images and i obtained this result ,so i am not understanding what happen?

thanks alot for your reading.

Answer 1

[Image Analyst]

That's not a great method. A popular, fairly common way these days is SSIM http://en.wikipedia.org/wiki/SSIM

[mmm ssss]

image analyst,thank you in advance.

[Shashi]

I have also seen Visual Information Fidelity being used as a measure of image quality. Which one is better out of the two? And to be very specific, if we want to measure the enhancement made by an image, which standard image do we compare it with?