1. An object detection apparatus mounted in a vehicle, comprising: a storage storing plural image recognition dictionaries each describing reference data for an object to be detected, and plural image recognition techniques each used to detect the object from an input image captured by an imaging unit of the vehicle with use of one of the plural image recognition dictionaries; a first acquirer configured to acquire an operating state of a lighting device of the vehicle; a selector configured to select, according to the operating state of the lighting device acquired by the first acquirer, one of the plural image recognition dictionaries stored in the storage and one of the plural image recognition techniques stored in the storage; and a detector configured to detect the object in the input image by applying image recognition processing to the input image with use of the image recognition dictionary and the image recognition technique selected by the selector.