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Visual gamma measurement and methods to compare gamma models
Author(s) -
Besuijen Jacobus
Publication year - 2007
Publication title -
journal of the society for information display
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.578
H-Index - 52
eISSN - 1938-3657
pISSN - 1071-0922
DOI - 10.1889/1.2770863
Subject(s) - brightness , gamma correction , computer science , matching (statistics) , artificial intelligence , computer vision , contrast (vision) , pattern recognition (psychology) , mathematics , statistics , optics , physics , image (mathematics)
— The correct estimation of the gamma exponent describing the tone‐reproduction curve of a display is an important step in color management. Several methods for visual gamma estimation have been proposed. In this study, the theoretical merits and practical problems of a number of these methods are discussed and compared, and improvements are suggested. A new method to compare gamma models with different numbers of parameters is introduced. In an experiment, spatial and temporal brightness‐matching methods were tested with 32 untrained subjects working on a CRT and an LCD with different resolutions under office and low‐illumination conditions. Illumination had no effect on gamma estimations. Subjects had great difficulties with spatial brightness matching at low resolutions. Temporal and spatial visual brightness matching for untrained subjects showed a larger gamma than photometric fits.