Method of inspecting solid body for foreign matter

Abstract

Small pieces of foreign matter on the surface of a cake such as freeze-dried preparations in a vial are detected as distinguished from cake surface irregularities including cake collapses and cracks that should be passed as being acceptable. The cake is imaged by a CCD camera or the like to produce an image signal representing an image of the cake. The level of an image signal which is higher than a predetermined upper limit is set to the upper limit and the level of an image signal which is lower than a predetermined lower limit is set to the lower limit. At least three pixel points, which include a point of interest and surrounding points one on each side of the point of interest, in an inspected region of the image are compared, and the point of interest is judged as being an abnormal point if the point of interest is brighter or darker than the surrounding points. An area in the inspected region is determined as containing foreign matter if the count of abnormal points in the area is larger than a predetermined lower limit and smaller than a predetermined upper limit.

Dependencies are inferred from the claim text.