Unmanned aerial vehicles, more typically known as drones are flying aircrafts that do not have a pilot on-board. For drones to fly through an area without GPS signals, developing scene understanding algorithms to assist in autonomous navigation will be useful. In this paper, various thresholding algorithms are evaluated to enhance scene understanding in addition to object detection. Based on the results obtained, Gaussian filter global thresholding can segment regions of interest in the scene effectively and provide the least cost of processing time. © 2019 Fuji Technology Press. All rights reserved.