Patent ID: 6097839
Filing Date: 2000-08-01
Classification: G06K

Abstract:
In a symbol reading apparatus capable of storing an image of a data collection symbol, the stored image being comprised of a plurality of pixels and the symbol having a predetermined pattern of geometric shapes, a method of locating portions of the shapes within the stored image, the method comprising:locating a stalking pixel of a shape of the symbol within the stored image;sequentially identifying adjacent pixels along an edge of the shape within the stored image from the starting pixel;performing at least one distortion compensating subroutine selected from a plurality of distortion compensating subroutines if an adjacent pixel cannot be located, wherein at least one of the plurality of distortion compensating subroutines does not fill in the adjacent pixel;selecting at least one linked pixel in the stored image based on the performing;repeating the sequentially identifying, performing and selecting;producing a set of pixels that identify at least a portion of the shape based on the repeating;determining if the set of pixels contains representations of one of several selected patterns of geometric portions for corresponding data collection symbology types, a first selected pattern corresponding to the predetermined pattern of geometric shapes of the data collection symbol, wherein the selected patterns of geometric portions include lines and curves represented by a series of substantially adjacent pixels, and wherein the selected patterns do not represent widths of a plurality of shapes as measured along an intersecting sampling path; andidentifying the data collection symbol in the stored image if the detected geometric portions correspond to the first selected pattern.