A novel fuzzy logic approach to online exposure time calculation of line scan cameras in industrial inspection

Exposure time calculation is an essential issue for digital cameras used in sensitive and secure industrial inspections to capture high quality image and consequently realise reliable performance of image processing algorithms. In this paper, we propose a novel exposure time calculation algorithm for line scan cameras in sensitive industrial inspection to deal with the problems caused by a harsh and dynamic environment. Since failure in capturing high quality images will cause the image processing algorithm to fail, the proposed algorithm will automatically examine whether there is a need to change the exposure time and estimate the optimal exposure time. The median of scanned line and the centre of histogram distribution are input to a fuzzy system to determine the need for exposure time modification and optimize exposure calculation. Experiments were conducted to compare the proposed method with other existing methods, and the results have demonstrated the effectiveness and robustness of the proposed method.