Abstract
Cracks of concrete surface are an important index that shows physical degradation of structure. Inspection efficiency will become better if cracks are automatically detected. The purpose of this study is to develop the system that can detect cracks automatically using pictures taken by a digital camera. In this system, destortion of a images is rectified automatically. Furthermore, one sheet of picture is composed by each component picture using matching techniques. The system also can detect cracks in me pictures, and length and width of cracks can be measured with sufficient accuracy.