Regular structural feature detection, involves determining at least one mathematical function based on degree of brightness or color tone on substrate surface, and then determining amplitude spectrum

摘要

The optical cover of a surface area (6) on the substrate surface (5) is detected optically. At least one mathematical function is determined based on the degree of brightness or color tone alternating regularly on the substrate surface. The amplitude spectrum of the mathematical function is then determined. An Independent claim is also included for a regular structural feature detecting device.