This paper discusses an image sharpness-based range sensing method and its applicability to the thickness measurement of paper materials. This method comprises a camera tilted at a known, non-orthogonal angle above the surface to be measured. From the image formed, it is possible to estimate the most focused row by summing the gradients inside each row. When images are taken simultaneously from two surfaces (i.e. reference surface and material surface), the thickness of a material can be determined by calculating the difference between the best focused rows. The suitability of the method to the thickness measurement of paper materials is evaluated by linearity measurements using different measurement configurations and different paper samples.

Date Published: 5 June 2008
PDF: 7 pages
Proc. SPIE 7022, Advanced Laser Technologies 2007, 70220P (5 June 2008); doi: 10.1117/12.803942

Published in SPIE Proceedings Vol. 7022:
Advanced Laser Technologies 2007
Ivan Alexandrov Shcherbakov; Risto Myllylä; Alexander V. Priezzhev; Matti Kinnunen; Vladimir I. Pustovoy; Mikhail Yu. Kirillin; Alexey P. Popov, Editor(s)