Patent ID: 7707425

Claim:
A computer-implemented method facilitating identification of a digital signal, the method comprising: obtaining a digital signal; deriving an identification value representative of the digital signal such that perceptually distinct digital signals result in identification values that are approximately independent of one another and perceptually same digital signals result in identical identification values, wherein the deriving comprises: transforming the digital signal into a digital signal transform; randomly dividing the digital signal transform into multiple chunks, each chunk containing signal data, wherein the dividing is carried out recursively to form hierarchical levels of overlapping chunks; and averaging, for each of the chunks, the signal data to produce corresponding chunk averages; generating, based in part on the chunk averages, an exponential distribution having multiple distinct quantization levels; randomly rounding each of the chunk averages to one of the quantization levels to produce rounded values; and hashing a composite of the rounded values; and indexing the digital signal using the identification value.