METHOD FOR RECOGNIZING RECESS FORMED ON SURFACE OF OBJECT

摘要

PROBLEM TO BE SOLVED: To surely clarify and recognize a recess even if a border between the recess and a protrusion is obscure. SOLUTION: The recess is formed on a surface of an object and captured as digital image data in gray scale form. An arbitrary processed region including the recess and wider than the recess is configured in the image data. The number of pixels are calculated and collected at each gray scale level in the processed region. A value x for maximizing a value of a differential expression F'(x) with regard to a distribution graph of the number of the pixels at each gray scale level or a virtual distribution graph, is determined as a threshold value. The recess is identified as a part in which pixels have the threshold value as the border or lower gray scale levels than the threshold value. COPYRIGHT: (C)2005,JPO&NCIPI