I am using Matlab normxcorr2 to calculate the cross correlation between several images, something like what has been done here: in Matlab documentation. There are some of the examples that I get negative values for xoffSet and yoffSet, but I am not sure what it means when these values are negative. Another issue, is practical since I need to give these xoffSet and yoffSet values as an input to coordinates of rectangle in an image, but since these are negative, the function throws an error. I googled it but no success in finding something that can explain such thing. I was thinking of just putting zero instead of negative values, but I'm not sure if that's a right approach. I would appreciate if someone can explain about the meaning of such negative values and how I can substitute such negative values with appropriate quantities.
It means the best match to template happens outside the image.
For instance, let's say your template is 5 by 5.
And you got answer which is -1, -1. It means the part of teh image which best matches you image is centered at [-1, -1] and you only have part of it in your image.
This is really extreme case.
If you share your data (2 Images) we'll be able to assist more.