“…Several studies have recently used surveillance techniques to automatically monitor livestock [ 1 , 2 , 3 , 4 ]. In this study, we focus on video-based pig monitoring applications with non-attached (i.e., non-invasive) sensors [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. Furthermore, we employ a top-view depth sensor [ 17 , 18 , 19 , 20 , 21 , 22 ] due to the practical difficulties presented in commercial farms where the light is turned off at night (i.e., light fluctuations, shadowing, cluttered backgrounds, varying floor status caused by urine/manure, etc.).…”