Development of a Chromatic/Luminance Contrast Scale

摘要

A model was developed to predict the detectability of small low-contrast targets viewed against a uniform background in daylight conditions. The model quantitatively describes the interrelationships among detectability, target size, target luminance, target chromaticity, background chromaticity, and background luminance. A theoretical approach was used to develop a general form of the predictive model. Two empirical studies were performed to estimate parameters of the model, and a final study was performed to validate the model. The final model is presented in two forms, both easily used in field situations. The first predicts detectability of a specified target (size, luminance and chromaticity) when viewed against a specified background (luminance and chromaticity). The second predicts the distance at which such a target will be detected. A guide to the use of the model is included. Keywords: Aids to navigation, Daymarks, Color vision, Chromatic contrast, Luminance contrast, and Detection model. (rh)