1. An image processing apparatus, comprising: a storing unit that stores learning data including a feature of a face image; an input unit that accepts input of a moving image; a face detection processing unit that reduces an image of a frame to be processed to a first level among several reduction levels to generate a reduced image of the frame to be processed, with one of frames included in the moving image accepted by the input unit as the frame to be processed, and compares the reduced image and the learning data to extract a face image from the reduced image; and an output unit that outputs a result of extraction of the face image, wherein when the extraction of the face image from the frame to be processed is ended, the face detection processing unit updates the frame to be processed to a next frame subsequent to the frame to be processed and generates a reduced image that is reduced to another level other than reduction levels adjoining the first level.