Detection of Calibration Pattern using Concentric Circles and Bimodal Distribution of Intensity Histogram
نویسندگان
چکیده
A calibration pattern detection method is proposed wherein a bimodal distribution is approximated for the intensity histogram of the calibration pattern. Because the histogram of the calibration pattern, such as black and white squares, is assumed to be bimodal, pattern detection is employed to determine the best threshold separating the two modes of the histogram. As most real images may include uneven illumination, the method divides the original image into subimages and then utilizes a different threshold to segment each subimage and approximate image parts of well separated modes. For binary images obtained from different threshold values of different subimages, region labeling and boundary tracing of labeled regions are performed and ellipses with close centers are detected as reference points of the calibration pattern among many background clutters
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