[Papers] Separation of Multi-path Components in Sweep-less Time-of-flight Depth Imaging with a Temporally-compressive Multi-aperture Image Sensor

Abstract

This paper demonstrates to separate multi-path components caused by specular reflection with temporally compressive time-of-flight (CToF) depth imaging. Because a multi-aperture ultra-high-speed (MAUHS) CMOS image sensor is utilized, any sweeping or changing of frequency, delay, or shutter code is not necessary. Therefore, the proposed scheme is suitable for capturing dynamic scenes. A short impulse light is used for excitation, and each aperture compresses the temporal impulse response with a different shutter pattern at the pixel level. In the experiment, a transparent acrylic plate was placed 0.3m away from the camera. An objective mirror was placed at the distance of 1.1 m or 1.9m from the camera. A set of 15 compressed images was captured at an acquisition rate of 25.8 frames per second. Then, 32 subsequent images were reconstructed from it. The multi-path interference from the transparent acrylic plates was distinguished.