  This paper presents DeepShadow, a one-shot method for recovering the depth
map and surface normals from photometric stereo shadow maps. Previous works
that try to recover the surface normals from photometric stereo images treat
cast shadows as a disturbance. We show that the self and cast shadows not only
do not disturb 3D reconstruction, but can be used alone, as a strong learning
signal, to recover the depth map and surface normals. We demonstrate that 3D
reconstruction from shadows can even outperform shape-from-shading in certain
cases. To the best of our knowledge, our method is the first to reconstruct 3D
shape-from-shadows using neural networks. The method does not require any
pre-training or expensive labeled data, and is optimized during inference time.
