Deep 3D morphable model refinement via progressive growing of conditional Generative Adversarial Networks

3D face reconstruction from a single 2D image is a fundamental Computer Vision problem of extraordinary difficulty. Statistical modeling techniques, such as the 3D Morphable Model (3DMM), have been widely exploited because of their capability of reconstructing a plausible model grounding on the prior knowledge of the facial shape. However, most of these techniques derive an approximated and smooth reconstruction of the face, without accounting for fine-grained details. In this work, we propose an approach based on a Conditional Generative Adversarial Network (CGAN) for refining the coarse reconstruction provided by a 3DMM. The latter is represented as a three channels image, where the pixel intensities represent the depth, curvature and elevation values of the 3D vertices. The architecture is an encoder–decoder, which is trained progressively, starting from the lower-resolution layers; this technique allows a more stable training, which leads to the generation of high quality outputs even when high-resolution images are fed during the training. Experimental results show that our method is able to produce reconstructions with fine-grained realistic details and lower reconstruction errors with respect to the 3DMM. A cross-dataset evaluation also shows that the network retains good generalization capabilities. Finally, comparison with state-of-the-art solutions evidence competitive performance, with comparable or lower error in most of the cases, and a clear improvement in the quality of the generated models.