1. An input apparatus that generates information for controlling devices based on a user's motions characterized by comprising: an image acquirer that acquires images; an image analyzer that analyzes the images acquired by the image acquirer and extracts image areas representing moving objects that are moved by the user; a coordinate extractor that extracts, from the image areas representing the moving objects extracted by the image analyzer, coordinates of predefined points of the moving objects and generates motion information representing trajectories of motions of the moving objects; a motion determiner that determines, based on the motion information, whether or not predetermined motions are performed and detects, when determined that the predetermined motions are performed, center coordinates of shapes formed by trajectories of the predetermined motions; a coordinate detector that detects, based on the motion information, specific coordinates on the trajectories of the predetermined motions; and an information generator that generates, based on positional relationships between points defined by the center coordinates and points defined by the specific coordinates, information for controlling the devices.