Methods and apparatus for generating signatures to identify media content using temporal signal characteristics
Methods and apparatus to identify media content using temporal signal characteristics are disclosed. An example method includes generating a reference signature based on a reference signal corresponding to known media, generating sums based on peaks in a media signal corresponding to media, identifying signal peaks based on the generated sums, generating a second signature based on normalized curve features, wherein the normalized curve features respectively correspond to the identified signal peaks at a corresponding temporal locations of the corresponding signal peak, and determining whether the media signal corresponds to the reference signal based on a comparison of the reference signature and the second signature.
1. An apparatus, comprising:
a peak detector to detect peaks of a media signal during time intervals and to output absolute values of the detected peaks;
a summer to generate interval sums respective to the time intervals based on the absolute values;
a peak identifier to identify signal peaks based on the interval sums; and
a feature generator to generate a first signature to identify the media signal, the first signature including first normalized curve features based on the signal peaks, at least one of the peak detector, the summer, the peak identifier or the feature generator being implemented with hardware, wherein the first normalized curve features have respective heights, widths, and center locations, the respective heights are equal, and the respective widths are equal.
2. The apparatus of claim 1 , further including a correlator to generate an index based on a comparison of the first normalized curve features of the first signature and second normalized curve features of a reference signature.
3. The apparatus of claim 2 , further including an index comparator to compare the index to a threshold to determine whether the first signature matches the reference signature.
4. The apparatus of claim 1 , further including a smoother to smooth the interval sums.
5. The apparatus of claim 1 , wherein the first signature has a substantially zero value except at temporal locations corresponding to the normalized curve features.
6. A method, comprising:
determining, by executing one or more instructions with a processor, absolute values of peaks of a media signal, the peaks detected during respective time intervals;
determining, by executing one or more instructions with the processor, interval sums respective to the time intervals based on the absolute values;
identifying, by executing one or more instructions with the processor, signal peaks based on the interval sums; and
generating, by executing one or more instructions with the processor, a first signature to identify the media signal, the first signature including first normalized curve features based on the signal peaks, wherein the first normalized curve features have respective heights, widths, and center locations, the respective heights are equal, and the respective widths are equal.
7. The method of claim 5 , further including generating an index based on a comparison of the first normalized curve features of the first signature and second normalized curve features of a reference signature.
8. The method of claim 6 , further including determining whether the first signature matches the reference signature based on the index.
9. The method of claim 5 , further including smoothing the interval sums.
10. The method of claim 5 , wherein the first signature has a substantially zero value except at temporal locations corresponding to the normalized curve features.
11. A computer readable storage device or storage disk comprising instructions, which, when executed, cause a processor to at least:
determine absolute values of peaks of a media signal, the peaks detected during respective intervals;
determine interval sums respective to the time intervals based on the absolute values;
identify signal peaks based on the interval sums; and
generate a first signature to identify the media signal, the first signature including first normalized curve features based on the signal peaks, wherein the first normalized curve features have respective heights, widths, and center locations, the respective heights are equal and the respective widths are equal.
12. The computer readable storage device or storage disk of claim 11 , further including instructions to cause the processor to generate a match index based on a comparison of the first normalized curve features of the first signature and second normalized curve features of a reference signature.
13. The computer readable storage device or storage disk of claim 12 , further including instructions to cause the processor to determine whether the first signature matches the reference signature based on the match index.
14. The computer readable storage device or storage disk of claim 11 , further including instructions to cause the processor to smooth the interval sums.
15. The computer readable storage device or storage disk of claim 11 , wherein the first signature has a substantially zero value except at temporal locations corresponding to the normalized curve features.