Abstract: A method for surface inspection named light-strip model-based highlight-line technique is proposed. Firstly, a light-strip including the axial line of the light-cylinder is taken to replace the light-cylinder, so that all beams are located in the same light source plane. Secondly, based on the distance function corresponding to the light-strip model proposed in this article, a series of highlight-dots on the surface are obtained by seeking points of intersection between the distance function and different planes. Finally, a continuous highlight-line cluster passing through those highlight-dots is fitted by using cubic Hermite interpolation. Examples show that this method is a comparatively ideal surface inspection technique, since it is able to overcome the following shortcomings of the method based on a light-cylinder model: highlight-lines have to be correlated with the datum light source, and the inspection results cannot reflect the surface fairness of curvature acutely diversified regions. In addition, the operating efficiency of this method is high.

Key words: surface inspection, highlight-line, light-strip model, light-cylinder model, distance function