Structured Light System with Accuracy Improved by the Use of LCD Pattern for Calibration

Abstract

Structured light system is an effective means of reconstructing 3D shape, requiring neither texture on the target object nor image feature correspondence establishment to operate. Its reconstruction accuracy hinges upon the quality of system calibration and how fine the illumination is encoded. This article describes a system design that makes use of an LCD panel as the calibration object, and incorporates a strip-shifting mechanism into the Gray code structured light for encoding the illumination. It is shown that, with the design, even a structured light system made of household-quality projector and camera can achieve accurate system calibration in far less image-capture steps. The quality of 3D reconstruction is also much strengthened. Performance of the calibration and 3D reconstruction mechanisms is presented in comparison with those of the traditional systems.

Keywords:

• 3D Reconstruction
• Structured Light
• Camera Calibration
• Gray Code