Structured Light in Sunlight

Project Page: http://www.cs.columbia.edu/CAVE/proje...

In most outdoor settings, vision systems operate on a limited power budget. For active systems, the light sources are often too weak to compete with sunlight, resulting in degraded performance. For instance, Kinect, a popular structured light device, cannot recover 3D shape in strong sunlight. In such scenarios, ideally, the power of the light source should be distributed 'smartly' over the scene according to when and where it is needed the most.

In this project, we show that by adapting the light distributing according to the ambient illumination, it is possible to perform fast and accurate 3D scanning outdoors on a limited power budget. The available power is concentrated into smaller regions if the ambient illumination is strong (e.g., direct sunlight), and is spread out to cover a larger area if the ambient illumination is weak (e.g., night time operation). We show that our method achieves detailed 3D structure outdoors in strong sunlight, even with low power light sources and a small acquisition time.

The authors are grateful to Yukio Sato of SpaceVision Inc. for making the laser scanner and associated software available for the experiments.