A study of a priori knowledge-assisted multi-scopic metrology for freeform surface measurement

Da Li, Chi Fai Cheung, Bo Wang, Mingyu Liu

Research output: Journal article publicationConference articleAcademic researchpeer-review


The traditional multi-scopic metrology system makes use of a micro lens array to capture a raw 3D-image of the target surface in a single snapshot through a CCD camera under normal illumination. However, the resolution of the system depends on the matching precision and efficiency of disparity information during the processing of the 3D raw data. In this paper, the a priori knowledge-assisted multi-scopic metrology is studied and an a priori knowledge-assisted multi-scopic metrology system is established which makes use of patterned illumination custom-designed based on the a priori knowledge of the target freeform surface profile. The a priori knowledge provides abundant versatile known information for a precise and efficient matching process so as to enhance the measuring performance. A customized disparity matching process based on the a priori knowledge is developed accordingly for high-resolution 3D surface reconstruction. An experimental study for measuring freeform surface is conducted to verify the feasibility of the proposed a priori knowledge-assisted multi-scopic metrology system through the comparison between that using normal illumination and a priori knowledge-assisted patterned illumination.

Original languageEnglish
Pages (from-to)337-342
Number of pages6
JournalProcedia CIRP
Publication statusPublished - 3 Sep 2018
Event15th CIRP Conference on Computer Aided Tolerancing, CIRP CAT 2018 - Milan, Italy
Duration: 11 Jun 201813 Jun 2018


  • a priori knowledge-assisted
  • autostereoscopy
  • freeform surface
  • multi-scopic metrology
  • Precision surface measurement

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Industrial and Manufacturing Engineering

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