In this work we propose a novel, highly practical, binocular photometric
stereo (PS) framework, which has same acquisition speed as single view PS,
however significantly improves the quality of the estimated geometry.
As in recent neural multi-view shape estimation frameworks such as NeRF,
SIREN and inverse graphics approaches to multi-view photometric stereo (e.g.
PS-NeRF) we formulate shape estimation task as learning of a differentiable
surface and texture representation by minimising surface normal discrepancy for
normals estimated from multiple varying light images for two views as well as
discrepancy between rendered surface intensity and observed images. Our method
differs from typical multi-view shape estimation approaches in two key ways.
First, our surface is represented not as a volume but as a neural heightmap
where heights of points on a surface are computed by a deep neural network.
Second, instead of predicting an average intensity as PS-NeRF or introducing
lambertian material assumptions as Guo et al., we use a learnt BRDF and perform
near-field per point intensity rendering.
Our method achieves the state-of-the-art performance on the DiLiGenT-MV
dataset adapted to binocular stereo setup as well as a new binocular
photometric stereo dataset - LUCES-ST.

提出了一种新颖、高度实用的双目光度立体（PS）框架，其采集速度与单视图 PS 相同，但显著改善了几何估计的质量。和最近的神经多视图形状估计方法（如 NeRF、SIREN 和多视图光度立体的反向图形方法）一样，我们将形状估计任务定义为通过最小化多个变化的光照图像估计的法线的表面法线差异，以及渲染表面强度与观察图像之间的差异，学习可微表面和纹理表示。我们的方法与典型的多视图形状估计方法有两个关键区别。首先，我们的表面不是用体积表示，而是用深度神经网络计算表面上各点的高度的神经高度图来表示。其次，我们使用了学习的 BRDF 并进行了点接近场强度渲染，而不是像 Guo 等人一样预测平均强度或引入兰伯特材料假设。我们的方法在针对双目立体设置进行适应的 DiLiGenT-MV 数据集以及新的双目光度立体数据集 - LUCES-ST 上取得了最先进的性能。