Real-Time Image Analysis for Nondestructive Detection of Metal Slivers in Packed Food

Foreign materials such as metal slivers and stones in packed food are known safety hazards that can lead to severe health problems. In this article, a real-time x-ray imaging inspection method is investigated for foreign material detection in chili mix packages. A novel image segmentation method combining Canny edge detection and region growing was successfully applied to overcome the problem caused by uneven thickness of chili mix packages and discriminate false positives caused by bubbles and foil wrinkles. The detection and false positive rates for metal slivers as small as 0.5 × 0.5 × 1 mm were 98.1% and 0.64%, respectively.