Bar code decoding using moving averages to break the (n,k) code barrier for UPC, EAN Code 128 and others

A method of decoding a bar coded representation of characters, which includes a plurality of bar elements separated by space elements of detectably different characteristics and in which the bars and spaces have one or more different widths and are separated by edges defining transitions between adjacent elements, and in which at least one element is known, comprising the steps of:

• measuring the distances between adjacent leading edges of the bars comprising the bar coded representation of characters, each distance between adjacent leading edges defining a pair of elements therebetween including a bar element and a space element, respectively;
• measuring the distances between adjacent trailing edges of the bars comprising the bar coded representation of characters, each distance between adjacent trailing edges defining a pair of elements therebetween including a space element and a bar element, respectively;
• measuring at least one distance between adjacent edges defining a pair of elements therebetween that includes one known element;
• measuring at least one distance between adjacent edges defining a pair of elements overlapping said at least one distance between adjacent edges defining a pair of elements therebetween that includes one known element;
• measuring a plurality of reference distances covering at least one pair of adjacent elements included in the bar coded representation of characters;
• categorizing said distances between adjacent leading or trailing edges defining pairs of elements with respect to measured reference distances;
• separating sequences of categorized distances defining pairs of elements into sequences of individual elements;
• and,
• identifying said bar coded representation of characters from said sequences of separated individual elements whereby said bar coded representation of characters can be decoded.

A method of decoding at least one bar coded representation of a character which includes a plurality of bar elements separated by space elements of detectably different characteristics and in which the bar and space elements have one or more different widths, comprising the steps of:

• measuring the distances between adjacent leading edges of the bars comprising the bar coded representation of characters, each distance between adjacent leading edges defining a pair of elements therebetween including a bar element and a space element, respectively;
• measuring the distances between adjacent trailing edges of the bars comprising the bar coded representation of characters, each distance between adjacent trailing edges defining a pair of elements therebetween including a space element and a bar element, respectively;
• measuring a plurality of reference distances covering at least one pair of adjacent elements included in the bar coded representation of characters;
• categorizing said distances between adjacent leading or leading edges defining pairs of elements with respect to measured reference distances;
• separating at least two of the categorized distances into respective individual elements, at least two of said separated individual elements comprising at least in part one bar coded representation of a character;
• and,
• identifying one bar coded representation of a character from categorized distances defining pairs of elements and at least two of separated individual elements whereby one bar coded representation of a character can be decoded.

A method of decoding a bar coded representation of characters, which includes a plurality of bar elements separated by space elements of detectably different characteristics, and in which the bar and space elements have one or more different module widths and are separated by edges defining transitions between adjacent elements, characters being coded according to bar code convention having logic structure, comprising the steps of:

• measuring the distances between adjacent leading edges of the bars comprising the bar coded representation of characters, each distance between adjacent leading edges defining a pair of elements therebetween including a bar element and a space element, respectively;
• measuring the distances between adjacent trailing edges of the bars comprising the bar coded representation of characters, each said distance between adjacent trailing edges defining a pair of elements therebetween including a space element and a bar element, respectively;
• measuring a plurality of reference distances covering at least one pair of adjacent elements included in the bar coded representation of characters;
• categorizing said distances between adjacent leading or trailing edges defining pairs of elements with respect to said measured reference distances;
• avoiding possible categorizing errors based on logic structure of bar code convention;
• and,
• identifying said bar coded representations of characters from the categorized distances whereby said bar coded representation of characters can be decoded.

A method of decoding a bar coded representation of characters, which includes a plurality of bar elements separated by space elements of detectably different characteristics, and in which the bar and space elements have one or more different module widths and are separated by edges defining transitions between adjacent elements, one or more of edges being mislocated more than other said edges, comprising the steps off

• measuring the distances between adjacent leading edges of the bars comprising the bar coded representation of characters in timing counts, each said distance between adjacent leading edges defining a pair of elements therebetween including a bar element and a space element, respectively;
• measuring the distances between adjacent trailing edges of the bars comprising the bar coded representation of characters in timing counts, each distance between adjacent trailing edges defining a pair of elements therebetween including a space element and a bar element, respectively;
• measuring a plurality of reference distances covering at least one pair of adjacent elements included in the bar coded representation of characters;
• categorizing said distances between adjacent leading or trailing edges defining pairs of elements with respect to said measured reference distances;
• increasing the accuracy of categorizing said distances based on subtracting said timing counts from an element on one side of a mislocated edge and adding timing counts to the element on the other side of said mislocated edge;
• and,
• identifying said bar coded representation of characters from the categorized distances whereby said bar coded representation of characters can be decoded.

A method of decoding a bar coded representation of characters, which includes a plurality of bar elements separated by space elements of detectably different characteristics, and in which the bar and space elements have one or more different module widths and are separated by edges defining transitions between adjacent elements, comprising the steps of:

• measuring the distances between adjacent leading edges of the bars comprising the bar coded representation of characters, each said distance between adjacent leading edges defining a pair of elements therebetween including a bar element and a space element, respectively;
• measuring the distances between adjacent trailing edges of the bars comprising the bar coded representation of characters, each said distance between adjacent trailing edges defining a pair of elements therebetween including a space element and a bar element, respectively;
• measuring a plurality of reference distances covering at least one pair of adjacent elements included in the bar coded representation of characters;
• categorizing said distances between adjacent .leading or trailing edges defining pairs of elements with respect to said measured reference distances with respect to a first direction;
• categorizing said distances between adjacent leading or trailing edges defining pairs of elements with respect to said measured reference distances a second time but with respect to a direction reverse to the first direction;
• and
• identifying said bar coded representations of characters from the categorized distances from the first or reverse directions or both said directions whereby said bar coded representation of characters can be decoded.

A method of decoding a bar coded representation of characters, which includes a plurality of bar elements separated by space elements of detectably different characteristics, and in which the bar and space elements have one or more different module widths and are separated by edges defining transitions between adjacent elements, comprising specified processing parameters and the processing steps of:

• measuring the distances between adjacent leading edges of the bars comprising the bar coded representation of characters, each said distance between adjacent leading edges defining a pair of elements therebetween including a bar element and a space element, respectively;
• measuring the distances between adjacent trailing edges of the bars comprising the bar coded representation of characters, each said distance between adjacent trailing edges defining a pair of elements therebetween including a space element and a bar element, respectively;
• measuring a plurality, of reference distances covering at least one pair of adjacent elements included in the bar coded representation of characters;
• categorizing said distances between adjacent leading or trailing edges defining pairs of elements with respect to said measured reference distances;
• processing said bar coded representation of characters again using different processing parameters or processing steps than processing parameters or processing steps to obtain another result;
• and,
• identifying said bar coded representation of characters from the categorized distances from one said processing or both said processings, whereby, said bar coded representation of characters can be decoded.