Director Field Model of the Primary Visual Cortex for Contour Detection

• Type of Material: Article
• Authors: Vijay Singh, Emory University; Martin Tchernookov, Emory University; Rebecca Butterfield, Emory University; Ilya Nemenman, Emory University
• Language: English
• Date: 2014-10-17
• Publisher: Public Library of Science
• Publication Version: Final Published Version
• Copyright Statement: © 2014 Singh et al.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1371/journal.pone.0108991
• Title of Journal or Parent Work: PLoS ONE
• ISSN: 1932-6203
• Volume: 9
• Issue: 10
• Start Page: e108991
• End Page: e108991
• Grant/Funding Information: This article published with support from Emory Libraries' Open Access Publishing Fund.; This work was supported in part by Army Research Office, 60704-NS-II (V.S., I.N.), James S. McDonnell Foundation, 220020321 (M.T., I.N.), and NIH, R90DA033462 (R.B.). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
• Keywords: cs.CV; q-bio.NC
• Research Categories: Physics, General; Physics, Optics

Abstract

We aim to build the simplest possible model capable of detecting long, noisy contours in a cluttered visual scene. For this, we model the neural dynamics in the primate primary visual cortex in terms of a continuous director field that describes the average rate and the average orientational preference of active neurons at a particular point in the cortex. We then use a linear-nonlinear dynamical model with long range connectivity patterns to enforce long-range statistical context present in the analyzed images. The resulting model has substantially fewer degrees of freedom than traditional models, and yet it can distinguish large contiguous objects from the background clutter by suppressing the clutter and by filling-in occluded elements of object contours. This results in high-precision, high-recall detection of large objects in cluttered scenes. Parenthetically, our model has a direct correspondence with the Landau - de Gennes theory of nematic liquid crystal in two dimensions.