Abstract:The computer digital image processing technology was used for steel plate width inspection in real-time. In the hardware structure aspect, the dual CCD cameras and the optical imaging laser scanning measurement technology were employed to improve the inspection accuracy of the system. According to the CCD imaging principles and similar triangle theorems, the computer model for width changing caused by steel plate width changing and steel plate edge floating was derived. The laser sub-line method that using blocking plate in the laser projected way was put forward to determine the measurement errors caused by steel plate edge floating, and the steel plate width was corrected according to the results of measurement. At the same time, through the analysis of CCD camera laser stripe optimal imaging method, the experimental calibration was implement for the system.The result manifests that the inspection accuracy of the system can meet the practical application requirements well.