@conference { ISI:000351597600002,
	title = {GRADIENT-BASED TIME TO CONTACT ON PARACATADIOPTRIC CAMERA},
	booktitle = {2013 20TH IEEE INTERNATIONAL CONFERENCE ON IMAGE PROCESSING (ICIP 2013)},
	series = {IEEE International Conference on Image Processing ICIP},
	year = {2013},
	note = {20th IEEE International Conference on Image Processing (ICIP), Melbourne, AUSTRALIA, SEP 15-18, 2013},
	pages = {5-9},
	publisher = {Inst Elect \& Elect Engineers; IEEE Signal Proc Soc},
	organization = {Inst Elect \& Elect Engineers; IEEE Signal Proc Soc},
	abstract = {The problem of time to contact or time to collision (TTC) estimation is largely discussed in perspective images. However, a few works have dealt with images of catadioptric sensors despite of their utility in robotics applications. The objective of this paper is to develop a novel model for estimating TTC with catadioptric images relative to a planar surface, and to demonstrate that TTC can be estimated only with derivative brightness and image coordinates. This model, called {\textquoteleft}{\textquoteleft}gradient based time to contact{{\textquoteright}{\textquoteright}}, does not need high processing such as explicit estimation of optical flow and feature detection and/or tracking. The proposed method allows to estimate TTC and gives additional information about the orientation of planar surface. It was tested on simulated and real datasets.},
	isbn = {978-1-4799-2341-0},
	issn = {1522-4880},
	author = {Benamar, F. and El Fkihi, S. and Demonceaux, C. and Mouaddib, E. and Aboutajdine, D.}
}
