@inproceedings{Black:IRCV:1994, title = {Time to contact from active tracking of motion boundaries}, author = {Ju, X. and Black, M. J.}, booktitle = {Intelligent Robots and Computer Vision XIII: 3D Vision, Product Inspection, and Active Vision}, pages = {26-37}, editors = {David P. Casasent}, publisher = {Proc. SPIE 2354}, address = {Boston, Massachusetts}, month = nov, year = {1994}, doi = {}, month_numeric = {11} }