Hybrid PCA based shape from shading for 3D head reconstruction

This paper describes a novel method for 3D head reconstruction by shape from shading (SFS) with initial conditions estimated using hybrid principal component analysis (HPCA). Prevalent Shape from Shading methods do not achieve good results on realistic images if a close initial estimation of the true surface is unavailable. This happens frequently in practical situations. To overcome this problem, we propose a novel shape from shading method which is based on multiple-level optimization with initial conditions derived by HPCA algorithm. We find that the HPCA algorithm provides reliable surface estimation that serves as initial conditions for the multiple-level optimization. The proposed method is also insensitive to albedo variations that frequently occur on head surfaces. Experimental results show that the method achieves accurate reconstruction of human heads.