Journal or Book Title
Measuring objects with a high variation range of surface reflectivity is challenging for any optical method: This paper addresses a high dynamic range scanning technique that can measure this type of object. It takes advantage of one merit of a phase-shifting algorithm: pixel-by-pixel phase retrieval. For each measurement, a sequence of fringe images with different exposures are taken: the brightest ones have good fringe quality in the darkest areas while the darkest ones have good fringe quality in the brightest areas. They are arranged from brighter to darker (i.e., from higher exposure to lower exposure). The final fringe images, used for phase retrieval, are produced pixel-by-pixel by choosing the brightest but unsaturated corresponding pixel from one exposure. A phase-shifting algorithm is employed to compute the phase, which can be further converted to coordinates. Our experiments demonstrate that the proposed technique can successfully measure objects with high dynamic range of surface reflectivity variation.
Copyright 2009 Society of Photo-Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic electronic or print reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.
Society of Photo-Optical Instrumentation Engineers
Zhang, Song and Yau, Shing-Tung, "High dynamic range scanning technique" (2009). Mechanical Engineering Publications. 122.