Geometric and photometric registration for real-time augmented reality

This paper proposes an augmented reality system with correct representation of shading and shadow. To realize a seamless augmented reality system, we need to resolve certain problems. The geometric and photometric registration problems are particularly important. These problems require the position of light sources and user´s viewpoint. The proposed system resolves these problems using a 3D marker which combines a 2D square marker and a mirror ball. The 2D marker and the ball are used to estimate the relationship between the real and virtual worlds and the positions of light sources in the real world, respectively.