Accession Number : ADA322076

Title :   Geometric and Radiometric Image Warping due to Displacement of Wide Field Optical Systems.

Descriptive Note : Technical rept.,

Corporate Author : DEFENCE SCIENCE AND TECHNOLOGY ORGANIZATION CANBERRA (AUSTRALIA)

Personal Author(s) : Caprari, Robert S.

PDF Url : ADA322076

Report Date : DEC 1996

Pagination or Media Count : 44

Abstract : This report investigates a problem that arises in the precise registration of images viewed from a moving wide field imaging sensor, such as an airborne missile threat warner. It analyses the geometry and radiometry of image formation by idealised but otherwise arbitrary, imaging optics, thereby determining the image plane irradiance distribution. The analysis extends to determining the transformation of the irradiance (i.e. image warping) due to arbitrary displacement of the optical system; such image warping being separable into geometric (i.e. image point shift) and radiometric (i.e. intensity scaling) components. Numerical simulations demonstrate the severity of the radiometric warping for wide field images - an especially important result, since radiometric warping is conventionally neglected in image registration. Exact solutions for the warping due to pure rotation of an idealised imager are presented. These are completely independent of the scene. An examination of the inclusion of imager translation shows that the warping becomes formally dependent on the scene topography, and emission/scattering directionality. Simulations of the use of block matching to achieve approximate registration are presented.

Descriptors :   *IMAGE REGISTRATION, *INFRARED SURVEILLANCE, ANTIMISSILE DEFENSE SYSTEMS, DISPLACEMENT, NUMERICAL ANALYSIS, SCALING FACTOR, AUSTRALIA, DISTORTION, RADIOMETRY, WIDE ANGLES, DIRECTIONAL, AIRCRAFT DEFENSE SYSTEMS.

Subject Categories : Infrared Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE