Illumination waveform optimization for time-of-flight range imaging cameras

A. D. Payne; A. A. Dorrington; M. J. Cree

doi:10.1117/12.889399

21 June 2011 Illumination waveform optimization for time-of-flight range imaging cameras

A. D. Payne, A. A. Dorrington, M. J. Cree

Proceedings Volume 8085, Videometrics, Range Imaging, and Applications XI; 80850D (2011) https://doi.org/10.1117/12.889399
Event: SPIE Optical Metrology, 2011, Munich, Germany

Abstract

Time-of-flight range imaging sensors acquire an image of a scene, where in addition to standard intensity information, the range (or distance) is also measured concurrently by each pixel. Range is measured using a correlation technique, where an amplitude modulated light source illuminates the scene and the reflected light is sampled by a gain modulated image sensor. Typically the illumination source and image sensor are amplitude modulated with square waves, leading to a range measurement linearity error caused by aliased harmonic components within the correlation waveform. A simple method to improve measurement linearity by reducing the duty cycle of the illumination waveform to suppress problematic aliased harmonic components is demonstrated. If the total optical power is kept constant, the measured correlation waveform amplitude also increases at these reduced illumination duty cycles. Measurement performance is evaluated over a range of illumination duty cycles, both for a standard range imaging camera configuration, and also using a more complicated phase encoding method that is designed to cancel aliased harmonics during the sampling process. The standard configuration benefits from improved measurement linearity for illumination duty cycles around 30%, while the measured amplitude, hence range precision, is increased for both methods as the duty cycle is reduced below 50% (while maintaining constant optical power).

Citation Download Citation

A. D. Payne, A. A. Dorrington, and M. J. Cree "Illumination waveform optimization for time-of-flight range imaging cameras", Proc. SPIE 8085, Videometrics, Range Imaging, and Applications XI, 80850D (21 June 2011); https://doi.org/10.1117/12.889399

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available