Application of Spatial Frequency Response as a Criteria for Evaluating Thermal Imaging Camera Performance

Published

April 1, 2008

Author(s)

Andrew J. Lock, Francine K. Amon, Anthony P. Hamins

Abstract

Police, firefighters, and emergency medical personnel are some of the first responders that are utilizing thermal imaging cameras in a very practical way every day. However, few performance metrics have been developed to assist first responders in evaluating thermal imaging technology. This paper describes one possible metric for evaluating spatial resolution with a practical application of Spatial Frequency Response (SFR) calculations for thermal imaging. As per ISO 12233 the SFR is defined as the integration below the Modulation Transfer Function (MTF) of a camera derived from the discrete Fourier transform of a camera image representing a knife edge target. This concept is used as a quantitative analysis of the cameras performance by integrating between the MTF function and the camera s characteristic nonuniformity. The resulting value can then be compared with a maximum spatial resolution degradation realized from human perception testing of task specific situations. The spatial resolution degradation is conducted in a very controlled method that allows a well defined SFR to be derived and to be used as a basis of comparison with the effective SFR determined from the thermal imaging cameras. The testing procedures described herein are being developed as a suite of tests to be incorporated into a performance standard covering thermal imaging cameras for first responders.

Citation

SPIE Conference Proceedings

Pub Type

Journals

Keywords

fire, first responders, SFR, spatial resolution, thermal imaging camera

Citation

Lock, A. , Amon, F. and Hamins, A. (2008), Application of Spatial Frequency Response as a Criteria for Evaluating Thermal Imaging Camera Performance, SPIE Conference Proceedings (Accessed February 2, 2026)