Good Morning,
It is like that It is done the Registration of the the ROI images and then it is made the fusion of the bigger images with the information of the transform parameters. The central points are the Geometric Centers. But I am getting (very) good results only with the ROIs mhd images with about the same size (dimensions). That is why I am asking about the no linearity of the rotations.
Thanks,
Luis Gonçalves