High-Resolution Time-of-Flight imaging

A novel approach to Time-of-Flight imaging based on Multi-Wavelength Interferometry

State of the art Time-of-Flight cameras suffer low depth resolution caused by the technical limitations in electronics manufacturing. High precision Time-of-Flight principles like single-wavelength interferometry are limited to smooth surfaces. We close the gap and solve this problem by applying teachings known from signal processing and multiwavelength interferometry. Paired with focal plane array sensors, our techniques acquire sub-mm resolution full field 3D data of any surface type within milliseconds or even in single-shot. The principle is of interest for a multitude of applications, because it combines the benefits of ToF imaging (compact, no occlusions) with the high resolution of triangulation (‘structured light’) methods.

	F. Willomitzer Single-shot synthetic wavelength holography: a flexible approach for high-resolution imaging through scattering media OPTICA Frontiers in Optics (FiO) Health Symposium, Tacoma, 2023 [Full Video]
	F. Willomitzer The Computational 3D Imaging and Measurement Lab - From Fast and Precise 3D Sensors to Looking Around Corners Industrial Affiliates Fall Meeting, University of Arizona, 2023 [Full Video]
	F. Li, F. Willomitzer, M. Balaji, P. Rangarajan, O. Cossairt (* joint first authors) Exploiting Wavelength Diversity for High Resolution Time-of-Flight 3D Imaging IEEE International Conference on Computational Photography (ICCP), 2021 [Jump to talk (26:36)] [Full Session Video]
	Y. Wu, F. Li, F. Willomitzer, A. Veeraraghavan, O. Cossairt (* joint first authors) WISHED: Wavefront Imaging Sensor with High resolution and Depth ranging IEEE International Conference on Computational Photography (ICCP), 2020 [Jump to talk (17:45)] [Full Session Video]
	F. Willomitzer Utilizing Nature’s Limits for Better Computational 3D Imaging Center For Robotics and Biosystems Seminar, Northwestern University, USA, 2022 [Full Video] , [Jump to Project (41:05)]
	F. Willomitzer Synthetic Wavelength Holography – Imaging around Corners and through Scattering Media at the Physical Space-Bandwidth Limit Physics Colloquium Talk Series, University Erlangen-Nuremberg, Germany, 2021 [Full Video]

Publications

Single-shot synthetic wavelength imaging: Sub-mm precision ToF sensing with conventional CMOS sensors
M. Ballester, H. Wang, J. Li, O. Cossairt, F. Willomitzer (* joint first authors)
Optics and Lasers in Engineering 178

Synthetic Wavelength Imaging - Utilizing Spectral Correlations for High-Precision Time-of-Flight Sensing
F. Willomitzer
Computational Imaging for Scene Understanding - Transient, Spectral, and Polarimetric Analysis, T. Funatomi, T. Okabe, Eds., ISTE Sciences
Download Preprint

Synthetic Light-in-Flight
P. Cornwall, M. Ballester, S. Forschner, MM Balaji, A. Katsaggelos, F. Willomitzer
ArXiv Preprint, 2024

Exploiting Wavelength Diversity for High Resolution Time-of-Flight 3D Imaging
F. Li*, F. Willomitzer*, M. Balaji, P. Rangarajan, O. Cossairt (* joint first authors).
IEEE Transactions on Pattern Analysis and Machine Intelligence (TPAMI), 2021
[Video (YouTube)]

WISHED: Wavefront Imaging Sensor with High resolution and Depth ranging
Y. Wu*, F. Li*, F. Willomitzer, A. Veeraraghavan, O. Cossairt (* joint first authors).
IEEE International Conference on Computational Photography (ICCP), 2020
[Video (YouTube)]

Wavefront sensing based depth sensor for macroscopic objects
Y. Wu*, F. Li*, F. Willomitzer, A. Veeraraghavan, O. Cossairt (* joint first authors).
OSA Computational Optical Sensing and Imaging, 2020

Towards Synthetic Light-in-Flight
P. Cornwall, M.Ballester, H. Wang, F.Willomitzer
Optica Computational Optical Sensing and Imaging, 2023

Dynamic High-Precision ToF Imaging utilizing Single-Shot Synthetic Wavelength Interferometry on Rough Surfaces
M. Ballester*, H. Wang*, J. Li, O. Cossairt, F. Willomitzer (* joint first authors).
Proceedings of the 124th DGaO Conference, Berlin, B14, 2023

Mega-pixel time-of-flight imager with GHz modulation frequencies
F. Li, F. Willomitzer, P. Rangarajan, O. Cossairt.
OSA Computational Optical Sensing and Imaging, CTh2A. 2, 2019

Micro Resolution Time-of-Flight Imaging
F. Li, F. Willomitzer, P. Rangarajan, A. Velten, M. Gupta, O. Cossairt.
OSA Computational Optical Sensing and Imaging, CM2E. 4, 2018

SH-ToF: Micro Resolution Time-of-Flight Imaging with Superheterodyne Interferometry
F. Li, F. Willomitzer, P. Rangarajan, A. Velten, M. Gupta, O. Cossairt.
IEEE International Conference on Computational Photography (ICCP), 2018

Fast Non-Line-of-Sight Imaging with High-Resolution and Wide Field of View using Synthetic Wavelength Holography
F. Willomitzer, P. Rangarajan, F. Li, M. Balaji, M. Christensen, O. Cossairt.
Nature Communications 12, 6647, 2021

High-Resolution Time-of-Flight imaging