Research Projects

Abstract: Time-of-flight (ToF) imaging is an active method that utilizes a temporally modulated light source and a correlation-based (or lock-in) imager that computes the round-trip travel time from source to scene and back. Much like conventional imaging ToF cameras suffer from the trade-off between depth of field (DOF) and light throughput—larger apertures allow for more light collection but results in lower DoF. This is especially limiting in ToF systems since they are active and are limited by illumination power, which eventually limits performance in long-range imaging or imaging in strong ambient illumination (such as outdoors). Motivated by recent work in extended depth of field imaging for photography, we propose a focal-sweep based image acquisition methodology to increase depth-of-field and eliminate defocus blur. Our approach allows for a simple inversion algorithm to recover all-in-focus images which is validated through simulation and experiment. We demonstrate a proof-of-concept focal sweep time-of-flight acquisition system and show results for a real scene.

Paper Links:

Click here to download the paper (1.41 MB), Or find the paper on IEEE Xplore.

Citation:

S. Honnungar, J. Holloway, A.K. Pediredla, A. Veeraraghavan, and K. Mitra (2016, September). Focal-sweep for large aperture time-of-flight cameras. In Image Processing (ICIP), 2016 IEEE International Conference on (pp. 953-957). IEEE.

[+] BibTex Citation

@inproceedings{honnungar2016focal,
title={Focal-sweep for large aperture time-of-flight cameras},
author={Honnungar, Sagar and Holloway, Jason and Pediredla, Adithya Kumar and Veeraraghavan, Ashok and Mitra, Kaushik},
booktitle={Image Processing (ICIP), 2016 IEEE International Conference on},
pages={953--957},
year={2016},
organization={IEEE}
}

Slides

Download the slides that accompany this paper here. Link to pdf [1.43 MB].