3-D surface inspection using interferometric grating and 2-D FFT based technique

Y. Y. Hung, S. H. Tang, Q. Zhu

Research output: Contribution to journalConference article

2 Scopus citations


A new method, based on the combination of interferometric grating projection technique and two-dimensional digital FFT (Fast Fourier Transformation) based phase-measurement technique, for three-dimensional shape measurement and surface inspection is presented in this paper. The projection technique generates an interferometric grating focusing everywhere in its illuminating space so that there is no focusing problem in this new technique. The phase measurement technique provides better separation of the desired depth information from noises and is capable of extracting accurate phase value at every pixel point. Consequently, the new method can obtain depth information corresponding to each pixel point in a high precision.

Original languageEnglish (US)
Pages (from-to)696-703
Number of pages8
JournalProceedings of SPIE - The International Society for Optical Engineering
Issue numberpt 2
Publication statusPublished - Dec 1 1990
EventOptical Testing and Metrology III: Recent Advances in Industrial Optical Inspection - San Diego, CA, USA
Duration: Jul 8 1990Jul 13 1990


ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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