1. an image processor comprising: an imaging unit that captures an image of a target area; a face region extraction unit that extracts a face region, which corresponds to a face of a person, from the image captured by the imaging unit; a distance estimation unit that estimates distance from the imaging unit to each position of the image captured by the imaging unit; a distance distribution calculation unit that sets up a distance estimation area, in the image captured, below the face region by a predetermined distance and calculates distance distribution from the imaging unit in the distance estimation area, using the distance estimated by the distance estimation unit; and a wheelchair presence determination unit that determines whether a person corresponding to the face region extracted is sitting in a wheelchair, by comparing the distance from the imaging unit of the face region estimated by the distance estimation unit with the distance distribution in the distance estimation area.