Single-pixel 3D reconstruction via a high-speed LED array

Three-dimensional reconstruction can be performed in many ways, among which photometric stereo is an established and intensively investigated method. In photometric stereo, geometric alignment or pixel-matching between two-dimensional images under different illuminations is crucial to the accuracy of three-dimensional reconstruction, and the dynamic of the scene makes the task difficult. In this work, we propose a single-pixel three-dimensional reconstructioning system utilizing structured illumination, which is implemented via a high-speed LED array. By performing 500 kHz structured illumination and capturing the reflected light intensity with detectors at different spatical locations, two-dimensional images of different shadows with 64 × 64 pixel resolution are reconstructed at 122 frame per second. Three-dimensional profiles of the scene are further reconstructed using the surface gradients derived by photometric stereo algorithm, achieving a minimum accuracy of 0.50 mm. Chromatic three-dimensional imaging via an RGB LED array is also performed at 40 frame per second. The demonstrated system significantly improves the dynamic performance of the single-pixel three-dimensional reconstruction system, and offers potential solutions to many applications, such as fast three-dimensional inspection.