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The Automated Objective Minimum Resolvable Temperature Difference (AO-MRTD) is an approach to provide an automated and objective measure of a thermal imager's performance. The algorithm is intended to provide a more accurate, reliable and cost effective figure of merit than traditional subjective MRTD measurements. MRTD values are calculated using signal-to-noise ratios obtained by match filtering digitized images of low contrast four bar patterns. Match filters are constructed from a high contrast image of the four bar patterns and the algorithm can assess sensor performance beyond Nyquist (similar to the minimum temperature difference perceived figure of merit). The MRTD values derived by the algorithm do not represent the minimum temperature differences perceived by human observers; however, simple modifications to the threshold signal-to- noise ratio result in human-like MRTD values. The algorithm has the flexibility to construct multiple types of match filters derived from a single high contrast image. Currently, the algorithm derives separate MRTD values for match filters corresponding to the bar pattern and it's derivative. Preliminary results suggest that a combination of the two match filters may yield a match to the human subjective MRTD results. The basic construction and operation of the algorithm is outlined.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only. |
