Alternating frequency captures for time of flight depth sensing

Abstract

Time-of-flight (ToF) 3D depth sensors are used virtual and augmented reality (VR/AR) due to their light weight, small form factor, low computation cost and high depth quality. Phase based ToF sensors can provide depth maps with reasonable resolutions (VGA or equivalent) at adequate framerates for traditional 3D sensing applications such as video surveillance, surface reconstruction, gesture recognition and skeleton tracking. Recently, more sophisticated input methods, such as articulated hand tracking, require substantially higher frame rates. Traditionally increasing the frame rate increases the sensor and compute power proportionally to the increased number of frames/second. However, wireless, wearable devices, have limited power capacity. The teachings of this disclosure enable a 2× increase in frame rate without increase to the camera power consumption, and with only modest increases in the computational load.