| 摘要 |
A method and apparatus for locating geometric shapes or edges thereof in data collection symbols initially samples and stores an image of light reflected from the symbol. Thereafter, two routines are performed. A first routine performs low level vision processing by identifying linked points along edges, lines, curves or within shapes. At least one of three distortion compensating subroutines compensate for blocking, breaking, gaps or other severe distortions affecting shapes in the stored image. Under a first subroutine, an edge of a shape is tracked until a stopping condition occurs, at which point the shape is crossed so as to continue tracking on an opposite edge. Under a second subroutine, previously collected linear curve information is used to identify a jump point to continue tracking following a stopping condition. Under a third subroutine, mathematical morphology techniques are employed to close gaps or move blockage in shapes in the stored image. Coordinates of linked points, which represent lines, curves and other geometric shapes, from the first routine are then employed by a second routine which identifies patterns within the identified lines/curves. Based on these identified patterns, types of symbols from various symbologies can be identified and located within the stored image.
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