Acquiring a radiance distribution to superimpose virtual objects onto a real scene

This paper describes a new method for superimposing virtual objects with co rrect shadings onto an image of a real scene. Unlike the previously propose d methods, our method can measure a radiance distribution of a real scene a utomatically and use it for superimposing virtual objects appropriately ont o a real scene. First, a geometric model of the scene is constructed from a pair of omnidirectional images by using an omnidirectional stereo algorith m. Then, radiance of the scene is computed from a sequence of omnidirection al images taken with different shutter speeds and mapped onto the construct ed geometric model. The radiance distribution mapped onto the geometric mod el is used for rendering virtual objects superimposed onto the scene image. As a result, even for a complex radiance distribution, our method can supe rimpose virtual objects with convincing shadings and shadows cast onto the real scene. We successfully tested the proposed method by using real images to show its effectiveness.