Methods and apparatus to optimize reference signature matching using watermark matching

An apparatus comprising:

• a network interface to collect monitoring data associated with a time period of a media event;
• a data segmenter to separate the monitoring data of the media event into segments, the segments including a first segment of the monitoring data and a second segment of the monitoring data, the first segment including a detected watermark and the second segment including an unhashed monitored signature;
• a watermark matcher to determine watermark coverage based on comparison of the detected watermark of the first segment with a reference watermark stored in a watermark reference database;
• an unhashed signature reference determiner to select an unhashed reference signature associated with the detected watermark of the first segment of the monitoring data;
• and
• a creditor interface to, in response to identifying a media event associated with the second segment based on comparison of the unhashed reference signature and the unhashed monitored signature of the second segment, credit media exposure based on the watermark coverage and the comparison of the unhashed reference signature and the unhashed monitored signature.

An apparatus, comprising:

• at least one memory;
• instructions in the apparatus;
• and
• processor circuitry to execute the instructions to:
• collect monitoring data associated with a time period of a media event;
• separate the monitoring data of the media event into segments, the segments including a first segment of the monitoring data and a second segment of the monitoring data, the first segment including a detected watermark and the second segment including an unhashed monitored signature;
• determine watermark coverage based on comparison of the detected watermark of the first segment with a reference watermark stored in a watermark reference database;
• select an unhashed reference signature associated with the detected watermark of the first segment of the monitoring data;
• and
• in response to identifying a media event associated with the second segment based on comparison of the unhashed reference signature and the unhashed monitored signature of the second segment, credit media exposure based on the watermark coverage and the comparison of the unhashed reference signature and the unhashed monitored signature.

At least one non-transitory computer readable storage medium comprising instructions which, when executed, cause at least one processor to at least:

• collect monitoring data associated with a time period of a media event;
• separate the monitoring data of the media event into segments, the segments including a first segment of the monitoring data and a second segment of the monitoring data, the first segment including a detected watermark and the second segment including an unhashed monitored signature;
• determine watermark coverage based on comparison of the detected watermark of the first segment with a reference watermark stored in a watermark reference database;
• select an unhashed reference signature associated with the detected watermark of the first segment of the monitoring data;
• and
• in response to identifying a media event associated with the second segment based on comparison of the unhashed reference signature and the unhashed monitored signature of the second segment, credit media exposure based on the watermark coverage and the comparison of the unhashed reference signature and the unhashed monitored signature.