Abstract

The detection of differences between optical images is an important processing operation with applications in medicine, meteorology, robotics, earth resonance studies, and other fields. In each, optical subtraction is used to suppress areas of commonality between images, thereby highlighting the differences. Many methods have been employed to perform optical image subtraction. Most of these are reviewed by Ebersole.¹ Since the publication of Ebersole’s review, real-time optical image subtraction using liquid crystal light valves (LCLVs) has been demonstrated.^2,3 These LCLV subtractors do not require phase matching fluids, and they can subtract time-varying images taken, for example, from a video terminal.

© 1988 Optical Society of America