Most important civil infrastructures are made of concrete, so accurate information by routine inspection is necessary for structure maintenance. Sometimes temporarily erected scaffoldings are needed for infrastructure inspection. Bridge inspection for example, the inspectors must stand on the platform to examine the underside of bridge, but such a process is risky. At present, several inspections system have been developed and applied to the infrastructure inspections in order to reduce the danger of accidents to the human inspectors. This paper proposes a computer vision technique based on concrete images to attempt to automatically detect cracks in concrete structure.