Pearson correlation coefficient between 2 images

Hi, I need to implement the PCC function between 2 images of same size without using any of the inbuilt function like corr2 etc in matlab. Any help would be appreciated

Answer 1

[Shashank Gupta]

Hi Ankur,

Simplest way to understand/execute the PCC is to check up the source code of the inbuild function "corrcoef" or if you are struggling with the steps on how to implement it. May be the following things helps you out.

• In order to find PCC between 2 images, you first need to flatten the images, convert them into either row vector or column vector.
• The mathematical expression for PCC can be found out here.
• Looking at the expression, you need to find couple of things for each flatten images, which are mean and norm. So simply use the inbuilt MATLAB function for the same.
• Then simply take the dot product between them

The vector expression will look something like :-

I hope this helps.

Cheers.