An Algorithm of Pig Segmentation from Top-View Infrared Video Sequences

Abstract

This paper considers the problem of pig automatic segmentation from infrared top view images of a pen. Particularly, an algorithm for accurate delineation of pig’s contour is presented. The method consists of two main steps. In the first step, a rough contour is determined using standard image processing methods. Next, the initial contour is gradually deformed so that it reflects the actual contour of the pig as much as possible. This effect is obtained by attracting initial contour points to the nearest local gradient peaks. In the last step, the contour is refined and smoothed by removing loops. This step incorporates analysis of the angles between contour segments passing through the consecutive contour points. Results of the proposed approach for sample infrared images of pigs in a pen are presented and discussed. They reveal that the method performs reasonably well with the average DICE score exceeding the level of 0.97 and the average Jaccard index above 0.95.