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Spatial Standard ObserverThe present invention relates to devices and methods for the measurement and/or for the specification of the perceptual intensity of a visual image, or the perceptual distance between a pair of images. Grayscale test and reference images are processed to produce test and reference luminance images. A luminance filter function is convolved with the reference luminance image to produce a local mean luminance reference image. Test and reference contrast images are produced from the local mean luminance reference image and the test and reference luminance images respectively, followed by application of a contrast sensitivity filter. The resulting images are combined according to mathematical prescriptions to produce a Just Noticeable Difference, JND value, indicative of a Spatial Standard Observer, SSO. Some embodiments include masking functions, window functions, special treatment for images lying on or near borders and pre-processing of test images.
Document ID
20120004310
Document Type
Other - Patent
Authors
Watson, Andrew B.
Date Acquired
August 25, 2013
Publication Date
March 20, 2012
Subject Category
Instrumentation and Photography
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
Patent
NASA-Case-ARC-14569-2|US-Patent-8,139,892
Patent Application
US-Patent-Appl-SN-12/807,375

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