Study 2: a novel cost-optimal camera array system for automatic monitoring of penned production swine

Close monitoring of production animals such as penned breeder swine is an integral process in commercial farms, particularly in increasing production. Identifying the exact time a sow has exhibit the first signs of estrous, for example, helps farm managers in optimizing the farm's insemination schedule that maximizes the sow's litter size potential. Most commercial farms in the Philippines still employ the inefficient manual labor to monitor large population of animals (that is usually numbering by the thousands), and thereby significantly missing their optimal production potentials. In this paper, authors present a novel cost-optimal design for a camera array (CA) whose seamless stitched videos are used as an input for an automated swine monitoring system (ASMS). The ASMS is designed to significantly improve the monitoring efficiency and availability. It relies on the input feed from a CA located above the animal pens, where its cameras are purposely arranged such that the behavior and mobility of all animals in all pens in a farm house can be tracked within an allowable minimum number of occlusion. The arrangement of the cameras depend solely on their respective focal angles (FA) and lens types (LT), while the number N of cameras to be used depends on the height H of the CA from the pen's floor. We considered two LTs in our design, rectilinear and fisheye. Rectilinear cameras capture images in the correct scale and perspective and using a narrower FA, while fisheyes capture distorted images with a wider FA. To achieve a cost-optimal CA, we minimized N without sacrificing seamless stitching and without relaxing the threshold number of occluded animals. Our CA arrangements given a fixed H and a fixed pen floor area are: (1) All rectilinear; (2) All fisheyes; (3) Alternating rectilinear and fisheye; (4) Alternating rectilinear-fisheye-rectilinear; and (5) Alternating fisheye-rectilinear-fisheye.