Dual Neural Networks Coupling Data Regression with Explicit Priors for Monocular 3D Face Reconstruction

We address the challenging issue of reconstructing a 3D face from one single image under various expressions and illuminations, which is widely applied in multimedia tasks. Methods built upon classical parametric morphable models (3DMMs) gain success on reconstructing the global geometry of a 3D face, but fail to precisely characterize local facial details. Recently, deep neural networks (DNN) have been applied to the reconstruction that directly predicts depth maps, showing compelling performance on detail recovery. Unfortunately, their reconstruction is prone to structural distortions owing to the lack of explicit prior constraints. In this paper, we propose dual neural networks that optimize one energy coupling data fitting with local explicit geometric prior. Specifically, we build one residual network upon traditional convolution layers in order to directly predict 3D structures by fitting an input image. Meanwhile, we devise a novel architecture stacking shallow networks to refine 3D clouds with geometric priors given by Markov random fields (MRFs). Quantitative evaluations demonstrate the superior performance of the dual networks over either end-to-end DNNs or parametric models. Comparisons with the state-of-the-art also show competitive reconstruction quality on various conditions.