Patent ID: 6164542
Filing Date: 2000-12-26
Classification: G06K

Abstract:
A method of decoding a bar code symbol representing encoded information, the bar code symbol including a plurality of relatively spaced bars having at least narrow and wide widths, and spaces between the bars having at least narrow and wide widths, the method comprising:receiving light reflected from the bar code symbol and producing an output signal therefrom that represents the bars and spaces comprising the bar code symbol, wherein the output signal includes valleys and peaks representing the resolved bars and spaces having the wide width, respectively, but wherein the output signal may fail to resolve at least some of the bars and spaces having the narrow width;without storing and analyzing a full representation of the output signal, producing a set of amplitude data based on amplitudes of the valleys and peaks in the output signal, and a set of feature distance data signal based on distances between the valleys and peaks in the output signal;identifying which of the bars and spaces are resolved by defining at least one threshold and identifying amplitudes from the set of amplitude data that extend beyond the threshold;determining a representative narrow width of the bars and spaces having the narrow width based on the identified resolved bars and spaces and the set of feature distance data;determining a number and location of the bars and spaces having the narrow width based on the representative narrow width, the identified resolved bars and spaces and the set of feature distance data; anddetermining the information encoded as in the bar code symbol.