In this paper, we present a correlation scheme that incorporates a color ring-projection representation for the automatic
inspection of defects in textured surfaces. The proposed color ring projection transforms a 2-D color image into a 1-D color
pattern as a function of radius. For a search window of width
W, data dimensionality is reduced from
in the 2-D image to
O(
W) in the 1-D ring-projection space. The complexity of computing a correlation function is significantly reduced accordingly.
Since the color ring-projection representation is invariant to rotation, the proposed method can be applied for both isotropic
and oriented textures at arbitrary orientations. Experiments on regular textured surfaces have shown the efficacy of the proposed
method.
Key words: Defect detection – Surface inspection – Colored textures – Ring projection – Correlation
Received: 30 March 2000 / Accepted: 24 July 2001
Correspondence to: D.-M. Tsai (e-mail: iedmtsai@saturn.yzu.edu.tw)