THREE-DIMENSIONAL OBJECT DETECTION DEVICE, AND THREE-DIMENSIONAL OBJECT DETECTION METHOD

A three-dimensional object detection device wherein, an assessment is made regarding whether the present is daytime or nighttime when detecting a three-dimensional object based on a captured image; when an assessment has been made that the present is daytime, the edges of a subject are extracted from a first edge extraction area, including a horizon reference area that references the horizon, and a threshold value for detecting the three-dimensional object is set based on the intensity of the edges in the first edge extraction area; when an assessment has been made that the present is nighttime, the edges of a subject are extracted from a second edge extraction area, including a road edge reference area that references the road edge, and a threshold value for detecting the three-dimensional object is set based on the intensity of the edges that are extracted from the second edge extraction area.