Banknote crack detection method and apparatus

A banknote crack detection apparatus, comprising:

• an image collection unit, configured to collect an optical transmission image of an inputted banknote;
• a pre-processing unit, configured to receive a banknote image signal collected by the image collection unit, and perform foreground region positioning and cutting on the banknote image signal;
• a crack detection unit, configured to receive a banknote foreground region image from the pre-processing unit, determine whether there is a pixel segment with a crack feature at an edge of a foreground region, determine that there is a crack at the edge of the foreground region if there is the pixel segment with the crack feature, detect whether the crack is extended to a deeper row or column than the edge in the same manner of detecting whether there is a crack at the edge, and accumulate a crack edge length and a crack depth;
• a determining unit, configured to determine whether the banknote is qualified according to a detection result of the crack detection unit, wherein a determining rule is that if there is no crack at any of four edges of the banknote, the inputted banknote is qualified and received;
• if the inputted banknote has a crack, and the crack edge length is greater than a preset threshold or the crack depth is greater than the preset threshold, the inputted banknote is unqualified and rejected;
• and if the inputted banknote has a crack, and the crack edge length is less than the preset threshold and the crack depth is less than the preset threshold, the inputted banknote is qualified and received;
• and
• a control unit, configured to control operation of each of the above units.