Recognizer of digital signal content

Abstract

Described herein is a technology for recognizing the content of digital signals. The technology determines one or more hash values for the original content of a digital signal. The scope of the present invention is pointed out in the appending claims.

1 . A computer-implemented method for hashing a digital signal, comprising: 
 transforming the digital signal into a digital signal transform;    randomly dividing the digital signal transform into multiple chunks, each chunk containing signal data;    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.    
   
   
       2 . A computer-implemented method as recited in  claim 1 , wherein the transforming is performed according to a MCLT technique.  
   
   
       3 . A computer-implemented method as recited in  claim 1 , wherein the averaging comprises computing a variance of the signal data in cases where the chunk average is approximately zero.  
   
   
       4 . A computer-implemented method as recited in  claim 1 , wherein the hashing comprises processing the rounded values to produce an intermediate hash value such that for perceptually distinct digital signals, the intermediate hash values differ approximately 60% of the time and for perceptually same digital signals, the intermediate hash values agree in all but approximately 20% of the time.  
   
   
       5 . A computer-implemented method as recited in  claim 1 , wherein the hashing comprises processing the rounded values using a Reed-Müller error correction code decoder.  
   
   
       6 . A computer-implemented method as recited in  claim 1 , wherein the hashing comprises processing the rounded values using a Reed-Müller error correction code decoder with an exponential pseudo-random norm.  
   
   
       7 . A computer-implemented method as recited in  claim 1 , wherein the hashing produces an intermediate hash value, further comprising reducing a size of the intermediate hash value via an error correction process.  
   
   
       8 . A computer-implemented method as recited in  claim 1 , wherein the digital signals are selected from a group consisting of digital audio signals, digital video signals, digital music signals, digital image signals, and digital multimedia signals.