The non-Lambertian reflection in plenoptic sampling

The plenoptic sampling theory studies the sampling rate of the 3D scene, and the spatial sampling rate can be determined by the spectrum analysis of the plenoptic function. In this paper we focus on the spectrum analysis of the non-Lambertian reflection. We establish a new scene model of non-Lambertian reflection by which the lightfield is resolved as an integration of the texture information, the illumination and the Bidirectional Reflectance Distribution Function (BRDF). Our analysis shows that the spectrum is expanded in the non-Lambertian reflection and the expanding range is controlled by the material property. More accurately, in the Phong model, the expanded range is controlled by a Gaussian function which the variance is Phong exponent. Our conclusion can be used to get a more accurate sampling rate when the object property is approximately known.