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Machine Vision and Applications

, Volume 12, Issue 3, pp 137–148 | Cite as

Building a color classification system for textured and hue homogeneous surfaces: system calibration and algorithm

  • Christian Daul
  • Ronald Rösch
  • Bernhard Claus
Original papers

Abstract.

We present a system for classifying the color aspect of textured surfaces having a nearly constant hue (such as wooden boards, textiles, wallpaper, etc.). The system is designed to compensate for small fluctuations (over time) of the light source and for inhomogeneous illumination conditions (shading correction). This is an important feature because even in industrial environments where the lighting conditions are controlled, a constant and homogeneous illumination cannot be guaranteed. Together with an appropriate camera calibration (which includes a periodic update), our approach offers a robust system which is able to “distinguish” (i.e., classify correctly) between surface classes which exhibit visually barely perceptible color variations. In particular, our approach is based on relative (not absolute) color measurements. In this paper, we outline the classification algorithm while focusing in detail on the camera calibration and a method for compensating for fluctuations of the light source.

Key words: Camera calibration – Color classification – RGB color space – HSI color space – Shading correction – Gamma-correction 

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Copyright information

© Springer-Verlag Berlin Heidelberg 2000

Authors and Affiliations

  • Christian Daul
    • 1
  • Ronald Rösch
    • 1
  • Bernhard Claus
    • 1
  1. 1.Institut für Techno- und Wirtschaftsmathematik (ITWM) e.V., Erwin-Schrödinger-Strasse, 67663 Kaiserslautern, Germany; e-mail: roesch@itwm.uni-kl.de; http://www.itwm.uni-kl.deDE

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