To meet the actual demand, the linear CCD technology is applied to tunnel crack detection, and an edge detection algorithm is proposed to measure the crack width. Firstly, the application form of linear CCD imaging technology in tunnel crack detection is introduced concretely in this paper. Then, the key influencing parameters of measurement are discussed. Finally, an edge detection algorithm based on the change of gray level in linear direction is proposed and it is verified by experiments. Experimental results indicated that the linear CCD imaging technology in tunnel crack detection could obtain measurement data quickly and improve the efficiency of tunnel cracks’ measurement, and that the detection algorithm could be used for the crack width measuring.
In order to meet the requirements of synchronous image acquisition in online industrial vision inspection, a new method based on image feature recognition is proposed. According to the method, the spatial characteristic information of sequence images has been calculated, and an algorithm under multi-constrained conditions which based on the trend of feature values of sequence images is established. The synchronous target image in online inspection is acquired by the trigger signal which was obtained by the algorithm under the condition of no dependence on external attachment. The method does not need to rely on the external position feedback device, and reduces the hardware cost. The algorithm has a better synchronization precision and adaptability, and has been successfully applied in practice.