This paper proposes an absolute phase unwrapping method for 3D measurement that uses two cameras and one projector. On the left camera image, each pixel has one wrapped phase value which corresponds to multiple projector candidates with different absolute phase values. We use geometric relationship of the system to map projector candidates into right camera candidates. By applying a series of candidate rejection criteria, a unique correspondence pair between two camera images can be determined. Then the absolute phase is obtained by tracing the correspondence point back to projector space. Experimental results demonstrate that the proposed absolute phase unwrapping algorithm can successfully work on both complex geometry and multiple isolated objects measurement.

Date Published: 4 May 2017
PDF: 8 pages
Proc. SPIE 10220, Dimensional Optical Metrology and Inspection for Practical Applications VI, 1022009 (4 May 2017); doi: 10.1117/12.2262564

Published in SPIE Proceedings Vol. 10220:
Dimensional Optical Metrology and Inspection for Practical Applications VI
Kevin G. Harding; Song Zhang, Editor(s)