The color-image quality of color overhead transparencies depends on properties of the imaging system used to create the transparency and illuminating and viewing conditions of the transparency such as the projector’s spectral power distribution, projector distance from the screen, and luminance, ambient lighting, screen gonio-spectral reflectance factor, and viewing distance and geometry. As different visual fields and/or luminance of those fields, some of these illuminating and viewing conditions can be taken into suitable
account using color-appearance models. A visual experiment is performed to determine whether color-appearance correlates of visual perception could be used to predict color-image quality for this
imaging modality. The Hunt 1991 color-appearance model is used to define correlates of hue, brightness, colorfulness, lightness, and chroma for both pictorial and business-graphic scenes viewed under several combinations of ambient illuminance and projector luminance. Gamut volume is defined based on either absolute attributes—hue, brightness, and colorfulness—or relative attributes—hue, lightness, and chroma. Seventeen observers performed a preference experiment generating interval scales of color-image quality. It is found that gamut volume defined by using correlates of hue, brightness, and colorfulness well predicted color-image quality. Of these correlates, colorfulness was the most important factor.