Detailed system topology is constructed according to the design goals covering the vast majority of steel mills.

A new dynamic image enhancement method is designed to overcome the uneven-lighting, over- or under-exposure.

A defect detection algorithm with adaptive thresholding mechanism is developed based on image block variance, entropy and average gradient.

The inspection speed of the proposed algorithms running on FPGA is evaluated.

Testing procedures and evaluation results from the applied hot-rolling mill are discussed.