Patent ID: 8474592

Claim:
A method for implementation by one or more data processors forming part of at least one computing system and for establishing at least one reference data set used for classifying items of currency, the method comprising: obtaining at least one measured electromagnetic response from at least one known item of currency; projecting, using at least one data processor, the measured electromagnetic response from the at least one known item of currency from a first multi-dimensional space to a second multi-dimensional space; applying, using at least one data processor, at least one axis reduction technique to the second multi-dimensional space thereby selecting a subset of axes of the second space, wherein the at least one reference data set used for classifying items of currency is represented by a subset of all measured responses obtained from the at least one known item of currency; and applying, using at least one data processor, at least one variable reduction technique to the subset of axes of the second space, wherein the at least one variable reduction technique obtains an approximation of the original subset of axes of the second space.