Image processing unit, object detection method, object detection program, and vehicle control system

An image processing unit which detects a target object in an imaging area of a captured image includes a static dictionary (259) and a dynamic dictionary (258) which contain feature amounts of candidate objects. A target object detector detects the target object on the basis of the dynamic dictionary when a target object has been detected. When the target object is not continuously detected in the following frames, the target object detector detects the target object on the basis of the static dictionary.