Crack Recognition and Segmentation Using Morphological Image-Processing Techniques for Flexible Pavements

MorphLink-C is a novel image-processing algorithm to connect crack fragments that are a common problem in crack recognition applications. The algorithm consists of two subprocesses: (a) the grouping of fragments by using a morphological dilation transform and (b) the connection of fragments by using a morphological thinning transform. MorphLink-C can be used with various crack extraction methods to connect crack fragments in crack line paths and for complicated crack shapes, such as single cracks, branched cracks, block cracks, and alligator cracks. MorphLink-C also provides a simple but accurate way to estimate an averaged crack width that is important in measuring cracking severity. The proposed method was validated by using realistic road surface images in different pavement cracking conditions. The results of the statistical hypothesis test showed that the proposed method could improve crack detection accuracy with the proposed crack defragmentation algorithm.