A given picture is scanned to store picture cell data thereof into memory positions of a first memory device. Non-boundary signs are written into a second memory device at its memory positions corresponding to the memory positions, filled by the picture cell data, of the first memory device. Coordinate...http://www.google.com.hk/patents/US4334274?utm_source=gb-gplus-share專利 US4334274 - Method of determining whether or not a region in a picture is within a closed boundary, and an apparatus therefor
