Sensor sharpening for computational color constancy

Sensor sharpening [J. Opt. Soc. Am. A 11, 1553 (1994)] has been proposed as a method for improving computational color constancy, but it has not been thoroughly tested in practice with existing color constancy algorithms. In this paper we study sensor sharpening in the context of viable color constancy processing, both theoretically and empirically, and on four different cameras. Our experimental findings lead us to propose a new sharpening method that optimizes an objective function that includes terms that minimize negative sensor responses as well as the sharpening error for multiple illuminants instead of a single illuminant. Further experiments suggest that this method is more effective for use with several known color constancy algorithms. (C) 2001 Optical Society of America