Patent ID: 7311262
Filing Date: 2007-12-25
Classification: G06K

Abstract:
1. A method for finding an edge of a finder of a symbol in an image, said symbol being represented by points of either a dark color or a light color and having one or more of said finders of a known pattern, said method comprising steps of: a) picking up data on a line possibly crossing an edge of a potential finder of said symbol, and calculating a runlength on the line; b) determining a potential point of said edge on said line where a color change occurs in said calculated runlength; c) determining a path extending from said potential point representing said edge according to said known pattern of said finder; and d) verifying whether said path is actually said edge said verifying comprising checking whether each point on said path is of the dark or white color by recalculating a threshold at least every predetermined amount of said point(s) and comparing each subsequent point to said recalculable threshold.