Document Type

Article

Publication Date

1-1998

Publication Source

Optical Engineering

Abstract

Some imaging systems employ detector arrays that are not sufficiently dense to meet the Nyquist criterion during image acquisition. This is particularly true for many staring infrared imagers. Thus, the full resolution afforded by the optics is not being realized in such a system. This paper presents a technique for estimating a high-resolution image, with reduced aliasing, from a sequence of undersampled rotated and translationally shifted frames. Such an image sequence can be obtained if an imager is mounted on a moving platform, such as an aircraft. Several approaches to this type of problem have been proposed in the literature. Here we extend some of this previous work. In particular, we define an observation model that incorporates knowledge of the optical system and detector array. The high-resolution image estimate is formed by minimizing a regularized cost function based on the observation model. We show that with the proper choice of a tuning parameter, our algorithm exhibits robustness in the presence of noise. We consider both gradient descent and conjugate-gradient optimization procedures to minimize the cost function. Detailed experimental results are provided to illustrate the performance of the proposed algorithm using digital video from an infrared imager.

Inclusive pages

247–260

ISBN/ISSN

0091-3286

Document Version

Published Version

Comments

Note: Paper was the winner of the 1998 Rudolf Kingslake Medal and Prize for the most noteworthy original paper to appear in Optical Engineering in 1998.

Publisher

Society of Photo-Optical Instrumentation Engineers (SPIE)

Volume

37

Issue

1

Peer Reviewed

yes

Keywords

high resolution, image reconstruction, aliasing, infrared, Nyquist, minimization.