Real-time full-field 3-D surface-shape measurement using off-the-shelf components and a single processor

Abstract

Phase-shifting fringe-projection methods have been increasingly used for three-dimensional (3D) object surface modeling to permit full-field measurement. This paper presents a real-time full-field high-resolution 3D surface-shape measurement system implemented with an efficient 3D shape measurement pipeline and triangular-pattern phase-shifting based on off-the-shelf components, software synchronization and a single computer-processor. The system projects computer-generated fringe patterns with a triangular intensity profile onto an object via a Digital Light Processing (DLP) projector. The projected patterns are electronically shifted and a CCD camera synchronized with the DLP projector by software captures the images from another direction. The captured images are processed by a single computer to reconstruct the 3D shape using triangular-pattern phase-shifting algorithms, and the model is displayed in real time. The 3D shape acquisition system achieved a speed of 5.6 fps for an image size of 648times494 pixels using the two-step triangular-pattern phase-shifting method, without any hardware synchronization or dual processing.