PROJECTION IMAGE AREA DETECTING DEVICE

摘要

A projection image area detecting device includes a projection image area detecting unit configured to detect marker image areas in a photographed image that is obtained by photographing a projection image area including a projection image. The marker image areas include marker images that are used for identifying four corners of the projection image area. The projection image area detecting unit detects the marker image areas by identifying a color included in the marker image areas that continues to change as time passes.