Color Inconstancy Index: A Proposal and Case Study for Consumer Digital Cameras

The rationale, formulae, and examples for assessing the color inconstancy of consumer digital cameras are pre­ sented. Its use is appropriate for evaluating the color/neutral balance precision of consumer digital camera systems with respect to illumination quality; specifically for a given rendering intent such as sRGB or ROMM. Adopting the ∆E94* color difference measure, an extended color incon­ stancy index (CII) is used to track the stability of color balancing algorithms across multiple illuminant types by effectively performing a variance analysis with respect to the illuminant variable for multiple color stimuli. Five differently branded 2 megapixel cameras were tested. The CII numerical results correlated well with visual engineer­ ing judgments. Results for both chromatic and nonchro­ matic samples are presented.