Structure light with laser speckle for object contour reconstruction

Ting Xuan Hua*, Cheng-Huan Chen, Augustine Tsai, Wen Kai Liu

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Invisible grid-pattern structure light has often been used for being shined on objects for contour reconstruction based on the distortion of grid pattern, for vehicle collision prevention etc. However, the structure light can be easily disturbed by surrounding nature light even if infra-red (IR) light source is used because natural light contains quite an amount of IR spectrum. In this paper, it is proposed that the structure light is provided from a highly coherent laser source, so that the structure light pattern reflected from the target object will contain not only the distorted irradiance distribution of grid pattern, but also laser speckle associated with it. The laser speckle pattern depends on the surface roughness of the target object, which provides extra information for extracting the distorted grid pattern from the background irradiance of surrounding natural light. The laser speckle pattern therefore helps to improve the immunity for surrounding light disturbance, and hence the robustness and reliability of contour reconstruction system. A binary surface relief phase-type diffractive optical element(DOE) has been proposed for generating desired pattern directly at far field when working together with laser light source. The design process is based on iterative Fourier transform algorithm(IFTA) in scalar diffraction theory.

Original languageEnglish
Title of host publicationOptical Components and Materials IX
DOIs
StatePublished - 26 Apr 2012
EventOptical Components and Materials IX - San Francisco, CA, United States
Duration: 25 Jan 201226 Jan 2012

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume8257
ISSN (Print)0277-786X

Conference

ConferenceOptical Components and Materials IX
CountryUnited States
CitySan Francisco, CA
Period25/01/1226/01/12

Keywords

  • Laser speckle
  • Obstacle detection
  • Structure light

Fingerprint Dive into the research topics of 'Structure light with laser speckle for object contour reconstruction'. Together they form a unique fingerprint.

  • Cite this

    Hua, T. X., Chen, C-H., Tsai, A., & Liu, W. K. (2012). Structure light with laser speckle for object contour reconstruction. In Optical Components and Materials IX [825712] (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 8257). https://doi.org/10.1117/12.906965