PURPOSE: To extract a special object pattern only from a drawing in which a complicated background and a special object pattern are overlapped and written by extracting a white area and a black area in the special object pattern respectively and separately and analyzing respective areas.
CONSTITUTION: A drawing is inputted by a picture reading device device 1, a pattern in the drawing is made binary and stored to a picture memory 2 as digitized picture data. An expanding contracting circuit 5 expands a black area only for the number of times in which a white area in a special object pattern disappears, and contracts, after that, a black area only for the number of times in which the black area is expanded. At a picture operation circuit 6, the 'or else' of picture data stored in the picture memory 2 before expanding and contracting operations and picture data stored in the picture memory 2 after expanding and contracting operations is obtained. In this way, a special- shaped white area is extracted.
TANAKA SATOSHI
IKEDA KAZUNARI
