1. An image processing apparatus that processes an image captured by a stereo camera and detects an object, the image processing apparatus comprising: a target object area specifying unit that uses distance data obtained by performing matching processing of the captured image of the stereo camera and specifies an image area in which an object is detected, as a target object area encircling an object at a same distance; a feature amount extracting unit that performs spatial filter processing of the target object area and extracts an image feature amount; and a smoke determining unit that decides whether or not the object in the target object area is a smoky object, based on the image feature amount in the target object area.