Gloss and Material Constancy in the Change of Light Source Size

Abstract

It is well-known that gloss appearances are observed as the results of association among various physical factors. In order to analysis this association, perception for constancy is very important characteristic features. In this paper, therefore, we verify the influence in gloss and material constancy under the artificial environment by changing the shape and size of light source. We performed two type observations in subjective evaluation, one is the “gloss appearance” which is mainly observed the distribution of specular reflection, and the other is “material appearance” which is mainly observed all distribution of specular and diffuse reflection influenced roughness as whole appearance of object. We prepared two kinds of object which has different roughness, and four kinds of light image generated by LCD projector. A paired comparative experiment was performed under different light source with real object. As the result, there was no obvious gloss constancy when we observed only the distribution of specular reflection, since the shape and size of light source gave a great influence to the gloss perception. On the other hand, an effect of material constancy appeared when we observed all distribution of specular and diffuse reflection influenced roughness as whole appearance of object.