1. A method for linking visually dissimilar local regions of a pair of images, comprising: obtaining at least first and second digitized images of an object; and using a 3D landmark detection method to determine a correspondence between a portion of the first digitized image and a portion of the second digitized image; wherein the portion of the first digitized image comprises a point of interest selected by a user as a user-defined click point, the portion of the first digitized image being a location within the first digitized image where a registration accuracy must be higher than registration accuracy in other portions of the first digitized image; and wherein said correspondence is determined using geometrical relations between the user-defined click point in the first digitized image and a predetermined point in the second digitized image.