Phase messaging method for time-of-flight cameras

Wenjia Yuan, Richard E. Howard, Kristin J. Dana, Ramesh Raskar, Ashwin Ashok, Marco Gruteser, Narayan Mandayam

Research output: Chapter in Book/Report/Conference proceedingConference contribution

7 Scopus citations


Ubiquitous light emitting devices and low-cost commercial digital cameras facilitate optical wireless communication system such as visual MIMO where handheld cameras communicate with electronic displays. While intensity-based optical communications are more prevalent in camera-display messaging, we present a novel method that uses modulated light phase for messaging and time-of-flight (ToF) cameras for receivers. With intensity-based methods, light signals can be degraded by reflections and ambient illumination. By comparison, communication using ToF cameras is more robust against challenging lighting conditions. Additionally, the concept of phase messaging can be combined with intensity messaging for a significant data rate advantage. In this work, we design and construct a phase messaging array (PMA), which is the first of its kind, to communicate to a ToF depth camera by manipulating the phase of the depth camera's infrared light signal. The array enables message variation spatially using a plane of infrared light emitting diodes and temporally by varying the induced phase shift. In this manner, the phase messaging array acts as the transmitter by electronically controlling the light signal phase. The ToF camera acts as the receiver by observing and recording a time-varying depth. We show a complete implementation of a 3×3 prototype array with custom hardware and demonstrating average bit accuracy as high as 97.8%. The prototype data rate with this approach is 1 Kbps that can be extended to approximately 10 Mbps.

Original languageEnglish (US)
Title of host publication2014 IEEE International Conference on Computational Photography, ICCP 2014
PublisherIEEE Computer Society
ISBN (Print)9781479951888
StatePublished - 2014
Event2014 6th IEEE International Conference on Computational Photography, ICCP 2014 - Santa Clara, CA, United States
Duration: May 2 2014May 4 2014

Publication series

Name2014 IEEE International Conference on Computational Photography, ICCP 2014


Other2014 6th IEEE International Conference on Computational Photography, ICCP 2014
Country/TerritoryUnited States
CitySanta Clara, CA

All Science Journal Classification (ASJC) codes

  • Mathematics (miscellaneous)


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