Iterative estimation of the topography by means of structured light

Amalia Martínez García; Juan Antonio Rayas-Alvarez; Héctor José Puga Soberanes; Katia Genovese

doi:10.1117/12.825658

Translator Disclaimer

10 September 2009 Iterative estimation of the topography by means of structured light

Amalia Martínez García, Juan Antonio Rayas-Alvarez, Héctor José Puga Soberanes, Katia Genovese

Author Affiliations +

Proceedings Volume 7432, Optical Inspection and Metrology for Non-Optics Industries; 743216 (2009) https://doi.org/10.1117/12.825658
Event: SPIE Optical Engineering + Applications, 2009, San Diego, California, United States

Abstract

It is measured the topography of a large object by using structured light. The type of fringes generated are equivalent to the produced by divergent beams. In this case the relation between the phase and the height is not linear. In this work it is proposed an iterative estimation to the topography measurement. It is taken in account the variation of period in xdirection of the projected grating and the perspective problem of CCD camera. The shape obtained is compared with the measurements realized with a commercial scanner. The stop criterion value c in the algorithm was chosen of .1 mm. This value corresponds to resolution in z of commercial scanner. To this case, three iterations are enough to reach the value of c. It is observed that after three iterations, the value of z is approximately the same. It is obtained a great discrepancy to the topography measurement when does not use correction in perspective and in the period variation due to divergent projection of the fringes. The main contribution of this work is show that it is important consider the variation of period and the perspective problem in the measurement of the topography to large objects.

Citation Download Citation

Amalia Martínez García, Juan Antonio Rayas-Alvarez, Héctor José Puga Soberanes, and Katia Genovese "Iterative estimation of the topography by means of structured light", Proc. SPIE 7432, Optical Inspection and Metrology for Non-Optics Industries, 743216 (10 September 2009); https://doi.org/10.1117/12.825658

ACCESS THE FULL ARTICLE