To reliably detect marks applied to lenses to be inspected on the basis of pickup images of the lenses inspected even in the case that the pickup images contain a large number of noise components.
This mark detection apparatus detects a plurality of temporary reference layout marks 4A-4C applied to a lens to be inspected L on the basis of pickup images of the lens to be inspected L (spectacle lens 1) includes an imaging device for imaging the lens to be inspect and acquiring the pickup images. One temporary reference layout mark 4A having a highest precision of matching is searched for and detected by pattern matching from the pickup images. A region in which another temporary reference layout mark 4B in a specific positional relation to the temporary reference layout mark 4A is present is set as a detection region 26. Pattern matching is executed only on the detection region to search for the temporary reference layout mark 4B. In the case that the temporary reference layout mark is not appropriately detected, image enhancement processing is performed on the detection region 26 to search for and detect the temporary reference layout mark 4B by pattern matching.
| JPH0688707A | 1994-03-29 |
Toru Yui
Hitoshi Kiyono