The present invention provides an image input apparatus into which a three-dimensional image as well as a two-dimensional image can be easily input. This image input apparatus includes an image pick-up unit, a projector unit, and a mover unit. The projector unit projects a predetermined projection light pattern onto an image object, and the image pick-up unit picks up the projection image containing distortions of the projection light pattern. The relative position between the projector unit and the image pick-up unit is fixed. The mover unit moves the image pick-up unit relatively with the projector unit, so that the image pick-up unit can pick up a plurality of projection images at different image pick-up locations.