Fault detection and evaluation method for printed item compares brightness values of contour reference points and surrounding field reference points for reference product with similar values for printed item

摘要

The fault detection and evaluation method has a learning phase and an operating phase, with the printed item scanned by an image detector for providing a digitized image. A reference product is scanned during the learning phase, for detecting its brightness characteristic, with detection of the coordinates of the brightness variations and storage of the brightness values for associated points, as contour reference point values, the brightness values of the remaining image points stored as surrounding field reference point values, for comparison with corresponding values obtained from the scanned printed item, for provision of fault value via a fuzzy logic model. An Independent claim for a fault detection and evaluation device is also included.