Color Effect on Readability Between Equivalent Luminance Contrast and L M S Cone Responses

摘要

In order to clarify the influence of color on readability, as an elementary knowledge of visibility, the equivalent luminance contrast of various chromatic documents was clarified and described determined by subjective experimentation. Equivalent luminance contrast is defined as the luminance contrast of the achromatic document whose readability is equal to that of a chromatic document, where background luminance and letter size are equal.rnThis is useful for designing colors to derive the equivalent luminance contrast from tristimulus values of letters and background colors in chromatic documents. However, the results of previous studies have shown that their same CIELAB color difference did not have the same influence on readability but demonstrated the same tendency for all background colors.rnThis paper examines and clarifies the relationship between the equivalent luminance contrast and the difference of cone responses correspondings to letters and background colors. Cone responses are calculated by the method in CIECAM 02. The equivalent luminance contrast can be related to combined contrasts of cone responses weighted for each background color. Coefficients weighted to the background color differ. This may suggest the fact that not only color difference of letters and background but also background colors effect readability.rnFurthers investigation of the effect on readability is necessary.