US Patent 7147161 Digitizing bar code symbol data

Processing an analog electrical signal containing information representative of reflected light from indicia including regions of different light reflectivity, wherein the analog electrical signal contains edge transitions corresponding to boundaries between adjoining regions of different light reflectivity of the indicia. The edge transitions of at least a part of the analog electrical signal are analyzed to determine a level of blur in that part of the electrical signal. Based on the determined level of blur, one of a plurality of different techniques is selected for processing that part of the electrical signal to produce a digitized electrical signal in which transitions in the digital level of the signal correspond to boundaries between adjoining regions of different light reflectivity of the indicia.