Projection Mapping System to a Widely Dynamic Sphere with Circumferential Markers

Image projection on spheres and their surroundings have been researched for all-around display and motion visualization.
However, wide-range projection onto a dynamic sphere can suffer from tracking errors and projection latency.
We propose a high-speed projection mapping system for dynamic spheres, and circumferential markers for sphere posture estimation. Marker detection based on ellipse appearance can easily start tracking, and is robust against interactive occlusion; therefore, the system enables projection mapping and rotational visualization for a dynamically moving sphere.
We experimentally confirmed sufficient pose estimation accuracy of the circumferential markers compared with initialized dot markers, and sufficient tracking ability against initialization, occlusion, and depth-direction movement. Demonstrations showed accurate, rotation-visualized projection onto a dynamic sphere, which is useful for sports practice applications.