Patent ID: 6236742
Filing Date: 2001-05-22
Classification: G06T

Abstract:
A method for detection of image variations based on the coherent superposition of first and second digitized images, comprising:digitally translating and rotating said second digital image in three dimensions until a mean quadratic error between said first and second digitized images is minimized in at least two dimensions;determining an optimal continuous lowpass vector field of three-dimensional displacements, such that applying said lowpass vector field to said translated and rotated digital image further minimizes said mean quadratic error between said first digitized image and said translated and rotated digital image in each of the imaged planes;determining an optimal continuous highpass vector field of three-dimensional displacements, such that improving said lowpass vector field by said highpass vector field further minimizes said mean quadratic error between said first digitized image and said translated and rotated digital image;calculating a divergence of said optimal continuous highpass vector field, regions of divergence of said optimal highpass vector field being representative of potential image variation; anddisplaying said regions of divergence superimposed on said first digital image.