Response nonuniformity modelling for colour imaging systems

In this paper, a theoretical analysis reveals that system radiation transmission nonuniformity and system radiation conversion nonuniformity have different forms. A colour imaging system response nonuniformity model is then proposed according to the two kind of nonuniformity of three channels. The model includes two models, one for brightness and one for chromaticity. The brightness model is built according to the nonuniformity of single channel. The chromaticity model is built as an error ellipse in the chromaticity diagram. The error ellipse can be also used as a representation parameter of the radiation conversion nonuniformity. The proposed models were verified using three commercial digital cameras. The experimental results show that the proposed nonuniformity model is correct. Moreover, the proposed representation parameter is an effective way to evaluate and characterize the nonuniformity of a colour imaging system. This research has value as a reference for the correction and evaluation of response nonuniformity in colour imaging systems.