Patent ID: 7263228

Claim:
A pattern-detection apparatus that detects a specific pattern contained in an image, said pattern-detection apparatus comprising: a binarizing unit that binarizes input image data to obtain binary image data, a first partial-image recognition unit that tests for a partial image contained in said binary image data, and that is part of said specific pattern and has an empty inside, wherein said partial-image recognition unit successively scans, in said binary image data, a pixel-block area of a predetermined size containing a target pixel, and said partial-image recognition unit determines if outermost lines of the pixel-block area are all OFF pixels and if a total number of ON pixels within the pixel-block area is within a prescribed range, a secondary partial-image recognition unit that tests the pixel-block area to obtain additional data concerning the pixels therein for purposes of determining the specific pattern, and a specific pattern determination unit that determines whether said specific pattern is contained in said binary image data, based on the recognition results obtained by said first partial-image recognition unit and the data obtained by secondary partial-image recognition unit.