FACE RELIGHTING FROM A SINGLE IMAGE

摘要

Disclosed is a method for estimating the apparent bi-directional reflectance distribution function field of a human face using anti-symmetric tensor splines, comprising: defining the complex geometry and reflectance properties of the human face by a field of spherical functions; approximating the field of spherical functions by anti-symmetric higher-order Cartesian tensors within a single pixel; applying a B-spline basis as the weighting function of the anti-symmetric higher-order Cartesian tensors; fitting the tensor spline basis to a given set of two-dimensional facial images of a human subject with a fixed pose and associated lighting directions by minimizing the energy of an objective function with respect to the unknown tensor coefficients of said anti-symmetric higher-order Cartesian tensors; and analytically computing the derivatives of the objective function for its efficient minimization.