Image processing for surface quality control in stainless steel production lines

In this paper we present an image processing algorithm to detect and measure the amount of residual oxide remaining on the surface of stainless steel coils for quality control in a production line. This algorithm processes in real time the images taken by the acquisition system which we have designed for this purpose and which has been installed in the finish line of a stainless steel production factory. We present here a more robust and reliable algorithm than the initial one, which has been adapted to deal with non-ideal conditions such as non-perfect homogeneous lighting, different surface finish, water marks, etc., which usually occur in practice.