In computer and robotic vision point clouds from depth sensors have to be processed to form higher-level concepts such as lines, planes, and objects. Bayesian methods formulate precisely prior knowledge with respect to the noise and likelihood of points given a line, plane, or object. Nonparametric methods also formulate a prior with respect to the number of those lines, planes, or objects. Recently, a nonparametric Bayesian method has been proposed to perform optimal inference simultaneously over line fitting and the number of lines. In this paper we propose a nonparametric Bayesian method for segment fitting. Segments are lines of finite length. This requires 1.) a prior for line segment lengths: the symmetric Pareto distribution, 2.) a sampling method that handles nonconjugacy: an auxiliary variable MCMC method. Results are measured according to clustering performance indicators, such as the Rand Index, the Adjusted Rand Index, and the Hubert metric. Surprisingly, the performance of segment recognition is worse than that of line recognition. The paper therefore concludes with recommendations towards improving Bayesian segment recognition in future work.
IOS Press, Inc.
6751 Tepper Drive
Clifton, VA 20124
Tel.: +1 703 830 6300
Fax: +1 703 830 2300 firstname.lastname@example.org
(Corporate matters and books only) IOS Press c/o Accucoms US, Inc.
For North America Sales and Customer Service
West Point Commons
Lansdale PA 19446
Tel.: +1 866 855 8967
Fax: +1 215 660 5042 email@example.com