Studies of 3-D model textures

We have constructed model textures with simple known structure. Control of the local reflectance properties and surface topography, facilitates the study of texture. We focus on the bi-angular dependence of the texture. We identify geometrical phenomena such as masking and shadowing as well as interreflections, and their effects to the spatial distribution of reflected light. Texture is studied through direct observations of the actual images and with the help of gray level image histograms measuring the proportion of gray tone in every image, and bidirectional reflection distribution function (BRDF) measurements describing the directionally dependent ratio of radiance to irradiance