Study on Finite Element Algorithm of Shape from Shading Based on Hybrid Reflection Model
Xinhang Liu · 2006
A finite element algorithm of shape from shading based on hybrid reflection is proposed in this paper.A smooth surface,which is approximated by surface elements,is expressed by a linear combination of a set of basis functions.Hybrid reflection models which containing diffuse reflectance and specular reflectance are used.Based on a set of basis functions which using discrete finite element technique,the hybrid reflection models are linearized.Digital image's characteristic is considered,so the discrete form of total brightness error of input image and reflection map is used.Then a set of linear equations about the unknown surface is derived using minimization approaches.The relative height of unknown surface is calculated using these equations by Kaczmarz algorithm.Then experiment on synthetic images and real images is given to illuminate the efficiency of the present method.At last performance of the method is also discussed.