I am working on two images (uint8) where the second image is a subset of the first Image. The offset of sub image with respect to the larger image is to be found and their correlation %. I am doing cross-correlation to find the correlation. I used ippiCrossCorrSame_Norm_8u_C1RSfs for the same.
When I use a scale factor of 0 for correlation it gives an offset of 0,0 always irrespective of the sub images supplied. Then I used a scale factor of -8. Then used ippiMaxIndx_8u_C1R to find the maximum correlation value and offset.
Now, How do I get the percentage of similarity between the two images, for eg.if they match well it is between 96% or if they dont match it will be 10%.
Please somebody help!!
Thanks in Advance
What do you exactly mean by saying "the second image is a subset of the first Image"
Is the second image an exact pixel-wise subset copy of the first image or only "very close" approximation and let's sayvaries due to a noise level or illumination changes?
You may want to study image registration subject and methods - see http://en.wikipedia.org/wiki/Image_registration
Don't you need a subpel level accuracy for your matching offset to achieve the maximum similarity between two? Phase correlation method seems like an attractivemethod here if there is no scalinginvolved.
PS. I have never tried ippiCrossCorrSame_Norm_8u_C1R and don't know how it works.