Appearance of Gold, Silver and Copper Colors of Glossy Object Surface

We investigated categorical regions and appearances of gold, silver and copper color, and glossiness for CG spheres with various chromaticities, lightnesses, and contrast glosses. It was found that the chromaticity regions of brown and yellow changed into gold color, those of gray and black into silver color, and a part of brown region changed into copper color with increase of contrast gloss. The magnitude estimates of gold, silver and copper color increased in high saturation chromaticity regions, achromatic regions, and medium saturation regions, respectively as the contrast gloss increased. As lightness levels increase gold and silver color estimates showed almost no change although copper color estimates decreased. It is suggested that the visual system would independently process glossiness and chromaticness of a surface in a lower level, and then, yield appearances of gold, silver and copper colors by combining them in a higher level.