In this paper, we propose to develop an inspection system that recognizes surface cracks on the brake pad and the types of brake pads of each car during the production process, on a conveyor belt. The brake pad is made from a mixture of materials, using high-heat and pressure. Therefore, the brake pad can be cracked and damaged on the surface during production. Our goal is to develop an effective detection system and application software to detect substandard product. A shadow is generated when the artificial light shines on the damaged of the surface of pad. Using the computer vision algorithm that is proposed we can detect the substandard product. Results from experiments confrim the performance of the proposed algorithm.