Computer comparison of pictures

Abstract : This dissertation reports the development of digital computer techniques for detecting changes in scenes by normalizing and comparing pictures which were taken from different camera positions and under different conditions of illumination. The pictures are first geometrically normalized to a common point of view. Then they are photometrically normalized to eliminate the differences due to different illumination, camera characteristics, and reflectance properties of the scene due to different sun and view angles. These pictures are then geometrically registered by maximizing the cross correlation between areas in them. The final normalized and registered pictures are then differenced point by point.