The evaluation of normalized cross correlations for defect detection

The normalized cross correlation (NCC) has been used extensively in machine vision for industrial inspection, but the traditional NCC suffers from false alarms for a complicated image that contains partial uniform regions. In this paper, we study the use of NCCs for defect detection in complicated images. The performance of NCCs in monochrome and color images, and the effect of image smoothing are empirically evaluated. The proposed NCC in a smoothed color image can effectively alleviate false alarms in defect detection applications. (C) 2003 Elsevier B.V. All rights reserved.