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 (TOF) cameras in research areas such as computer graphics, machine vision, and robotics. The state-of-the-art practice 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. Furthermore, a model for the noise distribution in the depth image is derived. This model can predict the performance of the proposed modulation method for each pixel in real time.Index Terms-Optical distance measurement component, phase measurement, phase shift algorithm, photonic mixer devices (PMDs), time-of-flight (TOF).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.