Fast Unsynchronized Unstructured Light

Abstract

This paper proposes a new approach in structured light correspondence to alleviate the camera-projector synchronization problem. Until now, great care was required to make sure that each camera image was corresponding exactly the correct pattern in the sequence. This was difficult to achieve with low-cost hardware or large size installations. In our method, the projector sends a constant video loop of a selected number of unstructured light patterns at a high frame rate (30 to 60 fps for common hardware), which are captured by a camera without any form of synchronization. The only constraint to satisfy is that the camera and projector frame rates are known. The matching process not only recovers the correct pattern sequence, but is impervious to partial exposures of consecutive patterns as well as rolling shutter effects.