Exploiting Spatio-Temporal Information for Light-Plane Labeling in Depth-Image Sensors Using Probabilistic Graphical Models

Article type: Research Article

Authors: Kravanja, Jaka^{1; *} | Žganec, Mario¹ | Žganec-Gros, Jerneja¹ | Dobrišek, Simon² | Štruc, Vitomir²

Affiliations: [1] Alpineon d.o.o., Ulica Iga Grudna 15, SI-1000 Ljubljana, Slovenia | [2] Faculty of Electrical Engineering, University of Ljubljana, Tržaška cesta 25, SI-1000 Ljubljana, Slovenia. E-mail: jaka.kravanja@alpineon.si

Correspondence: [*] Corresponding author.

Abstract: This paper proposes a novel approach to light plane labeling in depth-image sensors relying on “uncoded” structured light. The proposed approach adopts probabilistic graphical models (PGMs) to solve the correspondence problem between the projected and the detected light patterns. The procedure for solving the correspondence problem is designed to take the spatial relations between the parts of the projected pattern and prior knowledge about the structure of the pattern into account, but it also exploits temporal information to achieve reliable light-plane labeling. The procedure is assessed on a database of light patterns detected with a specially developed imaging sensor that, unlike most existing solutions on the market, was shown to work reliably in outdoor environments as well as in the presence of other identical (active) sensors directed at the same scene. The results of our experiments show that the proposed approach is able to reliably solve the correspondence problem and assign light-plane labels to the detected pattern with a high accuracy, even when large spatial discontinuities are present in the observed scene.

Keywords: depth images, structured light, probabilistic graphical models, spatio-temporal information

Journal: Informatica, vol. 27, no. 1, pp. 67-84, 2016