Abstract

Image subtraction techniques are powerful tools for detecting small changes in medical images, aerial pictures, and other scenes. By employing suitable optoelectronic devices, the incoherent subtraction technique can provide a fast method for image detection with simultaneous difference processing. Here we propose an incoherent technique of image subtraction for rendering visible in a linear fashion the first derivative of the phase structure. Our procedure consists of subtracting incoherently two images of the same phase object. Each image is spatial filtered by different methods, and it is recorded independently. The spatial filters are novel.

© 1987 Optical Society of America