“…Another work that started at the end of 1990s was the reflectance and illumination recovery of face images.In 1997,Marschner and Greenberg [43] developed an lighting system for face relighting.Given a camera model,the face geometry and albedo,and a set of basis lights,their system produces a set of basis images for the face under the basis lights.Given a new photograph,their system searches for a linear coefficients are essentially the lighting coefficients.In 1999,Marchner et al [45] developed an image-based system to measure the Bidirectional Reflectance Distribution Function(BRDF).They assumed that the surface area of an object is curved and all the point on the measured object have the same BRDF.In 2000,Debevec et al [44] developed a system to capture spatially varying reflectance properties of a human face's skin area.It require 2D array of light sources and a number of synchronized cameras,and the light sources and the cameras need to be calibrated.In 2005,Weyrich et al [46,47] developed a system to capture and measure a more general bidirectional surface scattering distribution function,which takes into account the translucent component of the skin reflectance.In 2007,Wang et al [48,49] proposed a spatially varying texture morphable model.They divide the image into multiple subrrgions and have a separate texture morphable model for each subregion.The spatial coherence between subregions is modeled as a Markov random field.Their technique is capable of handling harsh lighting conditions that cause cast shadows and saturations,as well as partial occlusions.…”