“Light shower: a poor man’s light stage built with an off-the-shelf umbrella and projector” by Okabe, Takayama, Ijiri and Igarashi

Compositing an actor or real-world object into a virtual background is a powerful and widely used tool in movic and TV production. To create a natural composite, it is necessary to maintain photometric consistency between the foreground object and the background environment. Various light stage systems have been developed to achieve this goal. Debevec et al. [Debevec et al. 2002] illuminated the actor by an array of inward-pointing RGB light-emitting diodes, and Mitsumine et al. [Mitsumine et al. 2005] surrounded the actor with back-projection screens and projected virtual images onto these screens. One problem with both of these strategies is that the systems involved are very expensive and time-consuming to build. We propose an inexpensive light stage system, Light Shower, which consists of an off-the-shelf projector and a white umbrella. The projector projects an image onto the white umbrella, which creates environment light for a human face or a real object inside the umbrella (see Figure 1).

1. Debevec, P., Wenger, A., Tchou, C., Gardner, A., Waese, J., and Hawkins, T. 2002. A lighting reproduction approach to live-action compositing. In Proceedings of SIGGRAPH 2002, ACM Press, New York, NY, USA, 547–556.
2. Mitsumine, H., Fukaya, T., Komiyama, S., and Yamanouchi, Y. 2005. Immersive virtual studio. In SIGGRAPH ’05: ACM SIGGRAPH 2005 Sketches, ACM Press, New York, NY, USA, 121.