Optimal exposure estimation in the image for structured light system

Abstract

In this paper we propose a method of optimal camera exposure estimation in the image for a structured light system. In structured light system, it is important to discriminate the patterns form the captured images which are illuminated by the projector. But every object in real environments has a different reflection due to object's material and surface's color property, so the precise discrimination of the projected pattern from the image in indoor environments is a hard problem where many objects are located together especially. And the camera exposure setting is not good. For better 3D range data, we estimate the optimal exposure at pixels so that makes the illuminated light by the projector can be captured properly by the camera. In order to obtain the optimal exposures about specific environments in structured light system, we should know how much intensity and/or brightness varies while the exposure is changed. So we introduce the novel method to estimate intensity by characteristic curves. This proposed method overcomes the conventional method's exposure problem and presents what is the optimal exposure at pixels is and how to obtain this setting. This has been proved to be feasible in many applications which need to measure the objects with different surface properties.