1. A method of registering images obtained by multiple modalities, comprising the steps of: obtaining a first intensity image representing bodily tissue or a bodily organ; obtaining a second intensity image representing the bodily tissue or bodily organ, the second intensity image being obtained using a different modality than the first intensity image; from the first intensity image, extracting multiple feature images wherein each feature image includes a plurality of pixels corresponding to the plurality of pixels in the first intensity image and each feature image represents a respectively different feature derived from the first intensity image; from the multiple feature images, determining, using a computer, an optimal feature image ensemble by determining a set of feature images selected from the multiple feature images that provide a greatest amount of information about the first intensity image; and using the optimal feature image ensemble in a predetermined similarity metric, registering, using the computer, the first intensity image to the second intensity image.