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Proceedings Paper

Study of the human recognition of images to evaluate current performance measures
Author(s): Alan H. Lettington; Alison M. Fairhurst; Kevin St. John Murphy
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Paper Abstract

Current performance measures for thermal imagers relate only indirectly to human recognition. However, as the probability of recognizing an image may be used as a measure of image quality, the relationship described in this work could contribute to the formation of a new objective performance measure for thermal imaging systems. The human recognition probabilities of several degraded shapes have been evaluated using computer generated images displayed on a computer monitor. The shapes investigated were blurred by convolving them with a range of two dimensional Gaussian functions. In subsequent trials, these blurred images were further degraded by sampling (in order to simulate the effect of detector arrays in an imager). Images of degraded shapes were presented to observers in a random order and with a random degradation. After each presentation the observer decided which was the most likely shape to represent the image displayed on the screen. A correlation has been found between the probability of recognition of a particular degraded shape and the relative contrast between the image of that shape and a similarly degraded circle of the same area. This is true whether the degradation is due to blurring alone or to blurring followed by sampling.

Paper Details

Date Published: 22 May 1995
PDF: 10 pages
Proc. SPIE 2470, Infrared Imaging Systems: Design, Analysis, Modeling, and Testing VI, (22 May 1995); doi: 10.1117/12.210048
Show Author Affiliations
Alan H. Lettington, Univ. of Reading (United Kingdom)
Alison M. Fairhurst, Univ. of Reading (United Kingdom)
Kevin St. John Murphy, Defence Research Agency Malvern (United Kingdom)

Published in SPIE Proceedings Vol. 2470:
Infrared Imaging Systems: Design, Analysis, Modeling, and Testing VI
Gerald C. Holst, Editor(s)

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