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  • Research Article
  • Open Access

Visual Inspection of Machined Metallic High-Precision Surfaces

EURASIP Journal on Advances in Signal Processing20022002:650750

  • Received: 31 July 2001
  • Published:


This paper presents a surface inspection prototype of an automatic system for precision ground metallic surfaces, in this case bearing rolls. The surface reflectance properties are modeled and verified with optical experiments. The aim being to determine the optical arrangement for illumination and observation, where the contrast between errors and intact surface is maximized. A new adaptive threshold selection algorithm for segmentation is presented. Additionally, is included an evaluation of a large number of published sequential search algorithms for selection of the best subset of features for the classification with a comparison of their computational requirements. Finally, the results of classification for 540 flaw images are presented.


  • visual inspection
  • surface reflection
  • flaw detection
  • segmentation
  • statistical classification
  • feature selection

Authors’ Affiliations

Institute of Automation, University of Leoben, Peter-Tunner-Strasse 27, Leoben, A 8700, Austria


© Pernkopf and O'Leary 2002