Abstract: Because underwater images generally have many problems, such as uneven illumination, low contrast, blurring and much noise, a novel underwater dam crack extraction algorithm based on Lorentz Information Measure is proposed to deal with the problems. First, the image blocks without crack information are removed according to Lorentz Information Measure. Second, features of connected domains, i.e., circularity and area, are extracted. Then k-means clustering method is used to achieve final cracks by 2-D feature space. The experimental results show that the proposed algorithm can extract cracks from underwater dam images precisely and effectively.

Key words: Lorentz information measure, image blocking, OTSU method, k-means clustering, dam crack