A Fast Shape from Shading Method for Diffuse Surfaces
Xinman Zhang · Xi'an Jiaotong Daxue xuebao · 2009
Focusing on the high error of shape from shading(SFS) for diffuse surfaces,a fast SFS method based on Oren-Nayar reflection model(FSFS-ON) is proposed.The image irradiance equation for diffuse surfaces is established under assumptions that the camera performs orthographic projection and its direction is the same as the direction of the light source.The equation is then transformed into the Eikonal partial differential equation(PDE) that includes the shape information of the surface.The viscosity solution of the resulting PDE is approximated by using the monotone upwind Godunov Hamiltonian and the fast marching method so that the heights of three-dimensional surface are obtained.Experimental results and comparisons on synthetic vase image show that the CPU time of the FSFS-ON algorithm is greatly reduced,compared with the existing methods of the same kind,and that the root mean square errors of the heights of the FSFS-ON algorithm are decreased by 35.04%,compared with the method based on Lambertian reflection model