1. An image processing device adapted to correct distortion of an image projected on a projection screen with projection light emitted from a projector, comprising: a detection section adapted to detect at least one of display positions of a plurality of predetermined figures displayed in a correction image projected by the projector on the projection screen, the plurality of figures arranged at densities varying in accordance with an incident condition of projection light to the projection screen; a distortion correction information generation section adapted to generate distortion correction information used for distortion correction of an image to be projected on the projection screen, based on the display position detected and correction image data representing the correction image; an acquisition section adapted to acquire image data representing the image to be projected on the projection screen; and a distortion correction section adapted to execute a distortion correction process using the distortion correction information on the image data acquired.