Fast Photometric Stereo by Time- and Spectral-Multiplexing With Crosstalk Handling

Photometric stereo is widely used to recover detailed surface normals. However, previous methods fail to balance the accuracy and efficiency. Conventional photometric stereo achieves high accuracy but suffers from low efficiency due to spectral-multiplexing and inefficient algorithms. In contrast, multispectral photometric stereo captures images efficiently with spectral-multiplexing, but its accuracy is harmed by crosstalk. In this paper, we aim to resolve the crosstalk issue to achieve fast photometric stereo (FPS) at low cost. First, we analyze the formulation and impact of crosstalk, showing that it significantly affects normal estimation, with external factors being primary contributors to crosstalk and internal factors being the secondary. Subsequently, we propose the FPS framework with a fast data capture scheme that combines time- and spectral-multiplexing to introduce constraints on crosstalk regarding both internal and external factors, along with a lightweight network, FPS-Net, to remove crosstalk caused by those factors based on constraints under such scheme. Finally, we build a real-world crosstalk-affected FPS dataset to evaluate the performance in handling crosstalk for normal estimation. Experimental results show the superior accuracy and efficiency of our method. The code and dataset are available at https://github.com/wxy-zju/FPS-Net.