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Proceedings Paper

Visual masking near spatiotemporal edges
Author(s): Thom Carney; Stanley A. Klein; Quingmin J. Hu
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Paper Abstract

One area of applied research in which vision scientists can have a significant impact is in improving image compression technologies by developing a model of human vision which can be used as an image fidelity metric. Scene cuts and other transient events in a video sequence have significant impact on digital video transmission bandwidth. We have therefore been studying masking at transient edge boundaries where bit rate savings might be achieved. Using Crawford temporal and Westheimer spatial masking techniques, we find unexpected stimulus polarity dependent effects. At normal video luminance levels there is a greater than fourfold increase in narrow line detection thresholds near the temporal onset of luminance pedestals. The largest elevations occur for pedestal widths in the range of 2 - 10 min. When the luminance polarity of the test line matches that of the pedestal polarity the masking is much greater than when the test and pedestal have opposite polarities. We believe at least two masking processes are involved; (1) a rapid response saturation in on- or off-center visual mechanisms and (2) a process based on a stimulus ambiguity when the test and pedestal are about the same size. The fact that masking is greatest for local spatial configurations gives one hope for its practical implementation in compression algorithms.

Paper Details

Date Published: 22 April 1996
PDF: 10 pages
Proc. SPIE 2657, Human Vision and Electronic Imaging, (22 April 1996); doi: 10.1117/12.238736
Show Author Affiliations
Thom Carney, Neurometrics Institute and Univ. of California/Berkeley (United States)
Stanley A. Klein, Neurometrics Institute and Univ. of California/Berkeley (United States)
Quingmin J. Hu, Univ. of California/Berkeley (United States)

Published in SPIE Proceedings Vol. 2657:
Human Vision and Electronic Imaging
Bernice E. Rogowitz; Jan P. Allebach, Editor(s)

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