Patent ID: 6508405
Filing Date: 2003-01-21
Classification: G06K

Abstract:
A barcode processing system for processing a photosignal produced by a photodetector in response to light reflected from a barcode, the barcode comprising elements including wide and narrow bars and spaces, onto the photodetector, the system comprising:a differentiator for producing a first derivative signal based on the photosignal; an analog to digital converter for producing a digital first derivative signal based on the first derivative signal, the first derivative digital signal comprising a series of samples; and a processor for processing the digital first derivative signal to recognize logic transitions represented by the photosignal, the processor being operative to perform: a threshold creation function to create a threshold based on peaks of the photosignal; a processing window function to identify processing windows containing processing regions of the first derivative signal wherein the first derivative signal exceeds the threshold; an area weighted mean function to process each of the regions of the first derivative signal falling within a processing window to identify a geometric center of the region; and a transition recognition function to recognize a logic transition at a geometric center of a processing region of the first derivative signal.