Methods and apparatus for audience measurement using global signature representation and matching

A method to determine a time offset between a first media signature comprising a first sequence of first data pairs and a second media signature comprising a second sequence of second data pairs, the method comprising:

• comparing, via a processor, ones of the first data pairs in the first sequence with ones of the second data pairs in the second sequence to determine original time differences between respective combinations of the ones of the first data pairs and the ones of the second data pairs;
• scaling and truncating, via the processor, the original time differences to determine scaled time differences between respective combinations of the ones of the first data pairs and the ones of the second data pairs;
• determining, via the processor, a histogram comprising bins representative of the scaled time differences, a first one of the bins of the histogram being representative of a first one of the scaled time differences, a value of the first one of the bins being determined to correspond to a count of the combinations of the ones of the first data pairs and the ones of the second data pairs having respective scaled time differences corresponding to the first one of the scaled time differences;
• and
• selecting at least one bin of the histogram to correspond to the time offset between the first signature and the second signature.