Resolution for Color photography

Although it is well known that luminance resolution is most important, the ability to accurately render colored details, color textures, and colored fabrics cannot be overlooked. This includes the ability to accurately render single-pixel color details as well as avoiding color aliasing. All consumer digital cameras on the market today record in color and the scenes people are photographing are usually color. Yet almost all resolution measurements made on color cameras are done using a black and white target. In this paper we present several methods for measuring and quantifying color resolution. The first method, detailed in a previous publication, uses a slanted-edge target of two colored surfaces in place of the standard black and white edge pattern. The second method employs the standard black and white targets recommended in the ISO standard, but records these onto the camera through colored filters thus giving modulation between black and one particular color component; red, green, and blue color separation filters are used in this study. The third method, conducted at Stiftung Warentest, an independent consumer organization of Germany, uses a white-light interferometer to generate fringe pattern targets of varying color and spatial frequency. Note: the abstract for this paper was originally submitted by one of us (PH), but since that time we decided to combine the work at Foveon with the recent work using interferometry at Stiftung Warentest since both research is on color resolution. Section 3 of this paper reports on research done at Stiftung Warentest which is an independent testing organization that compares everything fro