Patent ID: 8922830

Claim:
A printing machine comprising: a media advancement mechanism coupled to the printing machine; a media roll mounted on the media advancement mechanism; at least one optical sensor coupled to the printing machine and configured to scan a first non-harmonic mark and a second non-harmonic mark on the media roll; a processor coupled to a print controller and a computer readable medium; a media roll management application executable from the print controller or the computer readable medium, wherein the media roll management application is to: determine a first frequency of the first non-harmonic mark; determine a second frequency of the second non-harmonic mark; identify at least one attribute of the media roll based on the first frequency and the second frequency; and update the at least one attribute of the media roll to a look-up table, wherein the at least one attribute of the media roll includes a length of the media roll, and wherein the length of the media roll is identified by: determining a first phase of a first mark frequency of the firs non-harmonic mark and a second phase of a second mark frequency of the second non-harmonic mark; determining a first amplitude of the first phase and a second amplitude of the second phase; and determining an absolute amplitude of the media roll by combininig the first amplitude with the second amplitude.