We present projective parallel single-pixel imaging (pPSI), a 3D photography method that provides a robust and efficient way to analyze the light transport behavior and enables separation of light effect due to global illumination, thereby achieving 3D structured light scanning under global illumination. The light transport behavior is described by the light transport coefficients (LTC), which contain complete information for a projector camera pair, and is a 4D data set. However, the capture of LTC is generally time consuming. The 4D LTC in pPSI are reduced to projection functions, thereby enabling a highly efficient data capture process. We introduce the local maximum constraint, which provides constraint for the location of candidate correspondence matching points when projections are captured. Local slice extension (LSE) method is introduced to accelerate the capture of projection functions. Optimization is conducted for pPSI under several situations. The number of projection functions required for pPSI is optimized and the influence of capture ratio in LSE on the accuracy of the correspondence matching points is investigated. Discussions and experiments include two typical kinds of global illuminations: inter-reflections and subsurface scattering. The proposed method is validated with several challenging scenarios, and outperforms the state-of-the-art methods.

翻译：我们提出了投影式并行单像素成像（pPSI），这是一种三维摄影方法，能够稳健且高效地分析光传输行为，实现全局光照下光效应的分离，从而在全局光照条件下完成三维结构光扫描。光传输行为由光传输系数（LTC）描述，它包含了投影仪-相机对的完整信息，是一个四维数据集。然而，LTC的采集通常耗时较长。pPSI将四维LTC简化为投影函数，从而实现了高效的数据采集过程。我们引入了局部最大值约束，该约束为获取投影时的候选对应匹配点位置提供限制。同时，引入局部切片扩展（LSE）方法以加速投影函数的采集。针对pPSI在多种场景下进行了优化：优化了pPSI所需投影函数的数量，并探究了LSE中采集比率对对应匹配点精度的影响。讨论与实验涵盖了两种典型的全局光照类型：相互反射与次表面散射。该方法在多个具有挑战性的场景中得到验证，且性能优于现有最先进方法。