Modulation method for minimizing the depth distortion offset of lock-in TOF cameras

Registered depth and intensity data at a high frame rate, a compact design, low weight and a reduced power consumption have motivated the increasing usage of lock-in time-of-flight cameras in research areas such as computer graphics, machine vision and robotics. State of the art is to use continuous wave modulation with square waves for TOF cameras. Square waves can be easily generated digitally with a high accuracy and stability using programmable logic devices. In this paper a modulation method based on sine waves is proposed, which significantly reduces the depth distortion offset (wiggling effect) of lock-in TOF cameras.