The radiosity method for computing global illumination in Lambertian environments requires the computation of form factors. These are given by integrals for which some closed form solutions exist. In general however the integrals need to be approximated numerically. Various schemes have been proposed for this computation. Most of these are based on proximity assumptions which break down when su...

We present a recursive method for evaluating the impulse response of an indoor free-space optical channel with Lambertian reflectors. The method, which accounts for multiple reflections of any order, enables accurate analysis of the effects of multipath dispersion on high-speed indoor optical communication. We present a simple algorithm for computer implementation of the technique. We present c...

We consider the problem of estimating the shape and radiance of an object from a calibrated set of views under the assumption that the reflectance of the object is non-Lambertian. Unlike traditional stereo, we do not solve the correspondence problem by comparing image-to-image. Instead, we exploit a rank constraint on the radiance tensor field of the surface in space, and use it to define a dis...

The feasibility of new passive approach to 3D reconstruction, called Generalized Scene Reconstruction (GSR), is explored in this paper. Generalized scenes are defined to be "boundless" spaces that include non-Lambertian, partially transmissive, textureless and finely-structured matter. GSR enables such scenes to be effectively reconstructed by devicesusing-scene-reconstruction (DSRs) such as mo...

Lambertian photometric stereo with uncalibrated light directions and intensities determines the surface normals only up to an invertible linear transformation. We show that if object reflectance is a sum of Lambertian and specular terms, the ambiguity reduces into a 2dof group of transformations (compositions of isotropic scaling, rotation around the viewing vector, and change in coordinate fra...

We describe a method for designing a one-dimensional random surface that acts as a Lambertian diffuser. The method is tested using rigorous computer simulations and is shown to yield the desired scattering pattern. Optical devices that give rise to a scattered intensity that is proportional to the cosine of the scattering angle are frequently used in the optical industry, e.g. for calibrating s...

In photometric stereo one of the common problems may be inter-reflections occurring in concave surface parts of the object. They may locally blur the images in shade, resulting in a locally distorted shape. The effects may be more significant with increasing curvature of the concavity. Another problem may be non-Lambertian reflection, in which case shape reconstruction based on the Lambertian r...

We present a theory of image texture resulting from the shading of corrugated (three-dimensional textured) surfaces, Lambertian on the micro scale, in the domain of geometrical optics. The derivation applies to isotropic Gaussian random surfaces, under collimated illumination, in normal view. The theory predicts the structure tensors from either the gradient or the Hessian of the image intensit...

We present a method for recovering the shape of a single Lambertian surface, with unknown but uniform re ectance, from a single RGB image of the object. The method depends upon the linearity of the relationship between RGB sensor responses and surface normal directions that stems from the Lambertian model. The algorithm follows closely upon work on the photometric stereo method. However, that m...