Can we capture shape and reflectance in stealth? Such capability would be
valuable for many application domains in vision, xR, robotics, and HCI. We
introduce Structured Polarization, the first depth and reflectance sensing
method using patterns of polarized light (SPIDeRS). The key idea is to modulate
the angle of linear polarization (AoLP) of projected light at each pixel. The
use of polarization makes it invisible and lets us recover not only depth but
also directly surface normals and even reflectance. We implement SPIDeRS with a
liquid crystal spatial light modulator (SLM) and a polarimetric camera. We
derive a novel method for robustly extracting the projected structured
polarization pattern from the polarimetric object appearance. We evaluate the
effectiveness of SPIDeRS by applying it to a number of real-world objects. The
results show that our method successfully reconstructs object shapes of various
materials and is robust to diffuse reflection and ambient light. We also
demonstrate relighting using recovered surface normals and reflectance. We
believe SPIDeRS opens a new avenue of polarization use in visual sensing.

通过使用极化光的模式，我们引入了结构极化技术 (SPIDeRS)，首个深度和反射感应方法，为视觉、虚拟现实、机器人和人机交互等应用领域提供了捕捉形状和反射能力。我们的方法使用极化光角度的调制，实现了不仅深度，而且直接获得表面法线和反射信息的能力。通过实验验证，我们的方法成功重建了不同材料对象的形状，并且对漫反射和环境光具备鲁棒性，同时还展示了使用恢复的表面法线和反射信息进行重照明的能力。我们相信 SPIDeRS 开辟了极化应用在视觉感应领域的新途径。