An approach to defect detection in materials characterized by complex textures

摘要

This paper describes an expert system which detects and categorizes defects in digitized images of materials characterized by complex texture patterns. The system performs two major tasks: image segmentation and defect classification. Segmentation is done in two steps. First, individual texture samples are isolated. Second, a pyramid linking scheme is used to locate defects in each sample. This pyramid linking scheme can be fine-tuned to various textures and to the size of the defects to be detected. The defect classification method is dependent on the material being analyzed. This paper describes a hierarchical defect classification scheme for analyzing wood. The hierarchy incorporates a shape descriptor, size, and textural descriptors of individual defects. The system has been tested on parquet samples where it successfully detects and classifies defects.