1. An imaging method, the method causing a computer to execute processes, comprising: projecting intermittently a first image on a screen by a projector based on source image data; imaging the screen and a peripheral area of the screen at a non-projection timing for the intermittently projected first image by an imager so as to obtain captured image data; acquiring imager information including: an imager relative position of the imager with respect to the screen; and an imaging angle of the imager with respect to the screen; generating composition image data based on the source image data and the imager information, and composing the composition image data with the capture image data so as to generate a composition image, wherein the composition image includes a second image representing the composition image data composed in an area corresponding to the screen and a third image representing the captured image data composed in an area corresponding to the peripheral area.