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Object detection in natural backgrounds predicted by discrimination performance and modelsMany models of visual performance predict image discriminability, the visibility of the difference between a pair of images. We compared the ability of three image discrimination models to predict the detectability of objects embedded in natural backgrounds. The three models were: a multiple channel Cortex transform model with within-channel masking; a single channel contrast sensitivity filter model; and a digital image difference metric. Each model used a Minkowski distance metric (generalized vector magnitude) to summate absolute differences between the background and object plus background images. For each model, this summation was implemented with three different exponents: 2, 4 and infinity. In addition, each combination of model and summation exponent was implemented with and without a simple contrast gain factor. The model outputs were compared to measures of object detectability obtained from 19 observers. Among the models without the contrast gain factor, the multiple channel model with a summation exponent of 4 performed best, predicting the pattern of observer d's with an RMS error of 2.3 dB. The contrast gain factor improved the predictions of all three models for all three exponents. With the factor, the best exponent was 4 for all three models, and their prediction errors were near 1 dB. These results demonstrate that image discrimination models can predict the relative detectability of objects in natural scenes.
Document ID
20040172815
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Rohaly, A. M.
(U.S. Army Research Laboratory Aberdeen Proving Ground, MD 21005, United States)
Ahumada, A. J. Jr
Watson, A. B.
Date Acquired
August 22, 2013
Publication Date
December 1, 1997
Publication Information
Publication: Vision research
Volume: 37
Issue: 23
ISSN: 0042-6989
Subject Category
Life Sciences (General)
Distribution Limits
Public
Copyright
Other
Keywords
NASA Center ARC
NASA Discipline Space Human Factors

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