1. A detecting device comprising: an acquisition section for acquiring a plurality of images captured in a plurality of imaging devices provided at different heights; and a detection section for detecting a rising portion of an identical object toward the imaging devices based on a difference between lengths of the identical object in a height direction in the plurality of images; wherein the plurality of imaging devices are provided in a moving vehicle to capture images in a moving direction of the moving vehicle, and the detecting device further comprises a determination section for determining whether the identical object is an obstacle based on a determination result as to whether the identical object has a rising portion, wherein the determination section estimates a height of the identical object based on distance to the identical object; and an extraction section for extracting, from the plurality of images, an obstacle candidate as an candidate for the obstacle, wherein the determination section determines the identical object having a rising portion higher than or equal to a predetermined height among the obstacle candidates to be the obstacle.