A volumetric spin-off EGI for registration of volume datasets

A spin-off of the Extended Gaussian Image [1] (EGI) registration technique to volumetric datasets is presented. This spin-off technique directly allows recovery of the rotation (and indirectly may allow recovery of the translation) transformations that aligns one volumetric dataset to another. An extension of the basic EGI´s orientation histogram to volumetric datasets is also described. Using this histogram, a volume gradient orientation histogram, enables the registration (i.e., aligning) of two instances of one subject. The spin-off technique can be useful for fully automated registration without extraction of higher level features or markers. Results on multiple types of datasets are also reported.