Patent Number: 6,490,376

Title: Skew processing of raster scan images

Abstract: Run length encoded data derived from a raster scanner at an arbitrary angleto the horizontal direction of a rectilinear symbol such as atwo-dimensional PDF code is examined to detect the skew angle between thehorizontal direction of the symbol and the horizontal direction of theraster. Using the detected skew angle, a computer generates a set ofvirtual scan lines overlaid on the real scan lines. The computerpartitions the virtual scan lines and the real scan lines into associatedreal and virtual line segments having common intersection points. Thelocations of mark to space or space to mark transitions are mapped fromthe real line segments onto the virtual line segments. The system canhandle run length encoded data with low computational overhead.

Inventors: Au; Ka Man (Philadelphia, PA), Zhu; Zaioxun (Philadelphia, PA)


International Classification: G06K 7/14 (20060101); G06K 009/36 ()

Expiration Date: 12/02015