Tham khảo tài liệu 'understanding and applying machine vision part 7', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Page 187 Figure Erosion operation courtesy of ERIM . Figure Duality of dilation and erosion courtesy of ERIM . Page 188 Figure Mathematical morphology in processing of PC board images courtesy of General Scanning SVS . The results of the first operation-closing are depicted in Figure b . A difference image is shown in Figure c . A threshold is taken on the difference image Figure d . Filtering based on shape takes place to distinguish the noise from the scratch that is the detail that can fit in a structured element in the shape of a ring is identified in Figure e and subtracted Figure f . Figure g depicts the segmented scratch displayed on the original image. Figure Morphology operating on a scratch on manifold courtesy of Machine Vision International . Page 189 Figure Continued. Page .