Document Type

Article

Publication Date

11-1995

Publication Source

Optical Engineering

Abstract

We introduce and analyze techniques for the reduction of aliased signal energy in a staring infrared imaging system. A standard staring system uses a fixed two-dimensional detector array that corresponds to a fixed spatial sampling frequency determined by the detector pitch or spacing. Aliasing will occur when sampling a scene containing spatial frequencies exceeding half the sampling frequency. This aliasing can significantly degrade the image quality. The aliasing reduction schemes presented here, referred to as microscanning, exploit subpixel shifts between time frames of an image sequence. These multiple images are used to reconstruct a single frame with reduced aliasing. If the shifts are controlled, using a mirror or beam steerer for example, one can obtain a uniformly sampled microscanned image. The reconstruction in this case can be accomplished by a straightforward interlacing of the time frames. If the shifts are uncontrolled, the effective sampling may be nonuniform and reconstruction becomes more complex. A sampling model is developed and the aliased signal energy is analyzed for the microscanning techniques. Finally, a number of experimental results are presented that illustrate the perlormance of the microscanning methods.

Inclusive pages

3130-3137

ISBN/ISSN

0091-3286

Document Version

Published Version

Comments

Permission documentation is on file.

Publisher

Society of Photo-Optical Instrumentation Engineers (SPIE)

Volume

34

Issue

11

Peer Reviewed

yes

Keywords

Microscanning, aliasing, high resolution, subpixel, infrared imaging, motion estimation