Patent US 5,911,035

A method and apparatus is provided to determine affine disparity and affine invariant pattern distance from two image patterns. The method formulates the problem of determining affine disparity and affine invariant distances between two image patterns as one of finding an affine transform for an adjustable hypercolumn (HC) reference frame that maximally compensates the affine difference of the two image patterns. The image HC-coding and the difference vector is computed from two image patterns using specific orientation (SO) simple cell receptive fields employed in an HC-reference system. The Lie derivative of the difference vector is computed from image patterns using Lie germs. In accordance with one aspect of the invention, the affine transform that maximally compensates the affine difference between two image patterns is found by a gradient system wherein the gradient is calculated from the difference vector and its Lie derivatives. A closed loop adaptive HC-reference frame network is provided to extract binocular affine disparity using an energy minimization technique in a manner which permits for coincidental binocular fusion of the images in the HC-coding and determination of affine invariant pattern distance in general.