Matsushita Electric Works, Ltd.

Satoshi Yamatake

Tomoharu Nakahara

Mitsuru Shirasawa

Shozo Nomura

Toshinori Inoue

Shinji Hatazawa

An optical surface inspection method inspects a surface defect such as a crack, stain, and irregularity of an article, based upon an original grey value image of two dimensional configuration of the article and also upon an edge image representing a border line of the article surface. An area confined by the border line in the edge picture image is scanned for an edge which may be indicative of the defect. The pixel detected to have the edge is marked as a flag point. A plurality of pixels in the vicinity of the flag point are selected to be arranged in a direction generally perpendicular to the edge direction so that the selected pixels are evaluated in terms of their grey values whether there is a critical change between the selected pixels. When the critical change is acknowledged, the scanned edge is judged to be a clear transition between two contrasted regions and thus indicative of a defect.

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Osaka, Japan

Satoshi Yamatake