Colour-imager characterization by parametric fitting of sensor responses

This study, describes a novel method for characterizing the colorimetric an d photometric properties of three-channel color imaging devices. The method is designed to overcome some undocumented aspects of the imager-characteri zation problem: The effective spectral sensitivity profiles of the imager's color channels depend on the level of radiant input energy, and these prof iles must be known in order to determine the true intensity response charac teristics of the three channels. By fitting the response distributions of t he three color channels explicitly with low-dimensional models, the method takes these dependencies into account, and may, therefore, offer several ad vantages over other imager-characterization methodologies, particularly whe re illuminant-independent characterization is required. An application of t he technique is detailed, in which a CCD camera is characterized using only the Macbeth ColorChecker and a number of artificial illuminants. (C) 2001 John Wiley & Sons, Inc.