Period coded phase shifting strategy for real-time 3-D structured light illumination

Yongchang Wang, Kai Liu, Qi Hao, Daniel L. Lau, Laurence G. Hassebrook

Research output: Contribution to journalArticlepeer-review

83 Scopus citations


Phase shifting structured light illumination for range sensing involves projecting a set of grating patterns where accuracy is determined, in part, by the number of stripes. However, high pattern frequencies introduce ambiguities during phase unwrapping. This paper proposes a process for embedding a period cue into the projected pattern set without reducing the signal-to-noise ratio. As a result, each period of the high frequency signal can be identified. The proposed method can unwrap high frequency phase and achieve high measurement precision without increasing the pattern number. Therefore, the proposed method can significantly benefit real-time applications. The method is verified by theoretical and experimental analysis using prototype system built to achieve 120 fps at 640 × 480 resolution.

Original languageEnglish
Article number5770217
Pages (from-to)3001-3013
Number of pages13
JournalIEEE Transactions on Image Processing
Issue number11
StatePublished - Nov 2011


  • Phase shifting methods
  • phase unwrapping
  • real-time 3-D

ASJC Scopus subject areas

  • Software
  • Computer Graphics and Computer-Aided Design


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