An image projection device includes an acquiring unit configured to acquire a first ratio of a second distance to a first distance. The first distance is a distance between a projecting unit that projects a projection image and a first point in a projection area on which the projection image is projected. The second distance is a distance between the projecting unit and a second point in the projection area. The image projection device also includes an estimating unit configured to estimate, using the first ratio, light/dark levels of respective division areas into which the projection area is divided; and a light/dark-level processing unit configured to perform light/dark-level processing on areas in the projection image corresponding respectively to the division areas in accordance with the corresponding light/dark level.