Lambertian reflectance and linear subspaces

Illumination Insensitive Face Representation for Face Recognition Based on Modified Weberface

“…In [10], the authors introduced an illumination cone to generalize the illumination relationship between a set of face images in fixed poses but under varying illumination in the space of images. In [11], a spherical harmonic model is proposed to represent a low-dimensional linear subspace stretched by the face images of the same subject under varying illumination and expressions.…”

Relighting of Dynamic Video

“…Spherical harmonics are also used in the estimation of reflectance parameters of diffuse surfaces. However these techniques do not consider self shadows and colours [12].…”

Face Image Synthesis and Interpretation Using 3D Illumination-Based AAM Models

“…Human face can be considered approximately as a convex surface with Lambertian reflectance Basri et al (2003), Ramamoorthi & Hanrahan (2001). In Basri et al (2003), Basri et al, propose using spherical harmonic functions to model lighting for face recognition.…”

“…In Basri et al (2003), Basri et al, propose using spherical harmonic functions to model lighting for face recognition. Spherical Harmonics are a set of functions which form an orthonormal basis which is able to represent all possible continuous functions defined in the sphere.…”

“…In contrast to albedo, lighting is not necessarily constrained to a small variation interval. In fact, lighting affects appearance more than identity and pose, and presents many degrees of freedom (see Ramamoorthi & Hanrahan (2001) and Basri et al (2003)). During a fitting process, an initial model is gradually modified in each iteration until it match the input image.…”