A co-registration system provides a means for spatially warping an optical image of an object with another images of a similar object. The optical image may be a scatter image, and the second image may be the same type of image modality, or may be different. The co-registration may use landmarks selected by a user, or may make use of contour information derived from the images. The system may also include processing of three-dimensional volume data in the form of sets of two-dimensional slices for co-registration.