Simultaneous Evaluation of Microscopic Defects and Macroscopic 3-D Shape of Planer Object Derived from Specular Reflection Image Sequence

Hidetoshi MIIKE  Sosuke TSUKAMOTO  Keishi NISHIHARA  Takashi KURODA  

IEICE TRANSACTIONS on Information and Systems   Vol.E84-D   No.10   pp.1435-1442
Publication Date: 2001/10/01
Online ISSN: 
Print ISSN: 0916-8532
Type of Manuscript: PAPER
Category: Image Processing, Image Pattern Recognition
specular reflection,  active vision,  surface defects,  3-D shape,  

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This paper proposes a precise method of realizing simultaneous measurement of microscopic defects and the macroscopic three-dimensional shapes of planar objects having specular reflection surfaces. The direction vector field of surface tilt is evaluated directly by the introduction of a moving slit-light technique based on computer graphic animation. A reflected image created by the moving slit-light is captured by a video camera, and the image sequence of the slit-light deformation is analyzed. The obtained direction vector field of the surface tilt recovers the surface shape by means of integration. Two sample objects, a concave mirror and a plane plastic injection molding, are tested to measure the performance of the proposed method. Surface anomalies such as surface dent and warpage are detected quantitatively at a high resolution (about 0.2 [µm]) and a high accuracy (about 95%) in a wide area (about 15 [cm]) of the test object.