Accession Number : ADP006789

Title :   Velocity Filtering using Complementary Gratings in Photorefractive BSO,

Corporate Author : SOUTHAMPTON UNIV (UNITED KINGDOM) DEPT OF PHYSICS

Personal Author(s) : Hussain, Ghazanfar ; Eason, Robert W.

Report Date : 22 MAY 1992

Pagination or Media Count : 4

Abstract : Motion detection, velocity filtering and the detection of change in a given scene are all important aspects for optical processing architectures and systems. So far several different techniques have been reported in the literature that use either all optical or hybrid (optical plus electronic) schemes to implement novelty filter type operations. The electronic techniques however may have only limited applications due to the sequential ature of the process. For essentially all-optical schemes the intrinsic advantages of parallel image subtraction are clear. In this paper we report a different scheme for motion detection and velocity filtering which uses two spatially multiplexed gratings with a relative phase shift of 180 degrees, (known as complementary gratings). Such grating recording has already been implemented in a lithium niobate crystal.

Descriptors :   *OPTICAL PROCESSING, *OPTICAL DETECTION, *IMAGE PROCESSING, CRYSTALS, DETECTION, ELECTRONICS, FILTERS, FILTRATION, IMAGES, MOTION, PHASE SHIFT, VELOCITY, LITHIUM NIOBATES, MULTIPLEXING, GRATINGS(SPECTRA), REFRACTION, OPTICAL IMAGES, SYMPOSIA.

Subject Categories : Optical Detection and Detectors
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE