Patent ID: 7620249

Claim:
A computer implemented method of comparing a first pattern (A) represented by a first ordered set of elements (x i ) each having a value with a second pattern (B) represented by a second ordered set of element (u i ) each having a value, comprising iteratively performing the steps of: using at least one computer with accessible input/output to perform the following steps: (i) selecting a plurality of elements from the first ordered set; (ii) for each selected element of the first ordered set, selecting an element from the second ordered set, such that the selected elements of the second ordered set have, within the second ordered set, a set of positional relationships relative to each other that is a transformation of, the set of positional relationships that the selected plurality of elements of the first ordered set have relative to each other, (iii) comparing the value of each of the selected elements of the first ordered set with the value of the correspondingly positioned selected element of the second ordered set in accordance with a predetermined match criterion to produce a decision that the selected plurality of elements of the first ordered set does or does not match the selected plurality of elements of the second ordered set; (iv) in the event of a match, updating at least one similarity score (S AB ); wherein the step of selecting the elements of the second ordered set comprises choosing a value for at least one parameter (R, β, α) and selecting elements having a set of positional relationships (d i ′, d i ″) that is transformed from the positional relationship set (d i ) of the selected elements of the first ordered set in accordance with the parameter(s) wherein the said parameter (R) determines whether or not a reflection should be applied to the positional relationships.