Time-variant spatial masking for real-time single-photon imaging against strong ambient light.

Real-time single-photon imaging of the accurate reflectivity and depth is a challenge under strong ambient light. We propose a novel, to our knowledge, method to enhance the reflectivity image guided by the depth image and introduce a time-variant spatial mask (TV-SM) to optimize the global incident light flux. The proposed method dynamically loads the TV-SM onto a spatial light modulator (SLM) to achieve fast reconstruction. The experimental results demonstrate that the proposed method can accurately reconstruct both reflectivity and depth of targets moving at velocities of several meters per second, with an imaging rate of ~ 18 Hz. The above advantages indicate that our method has significant application potential in real-time imaging under strong ambient light.