Tuesdays the PTO issues new patents. Both of today's Spotlight Patents concern aspects of digital fingerprinting. Assigned to Dolby, the first patent addresses techniques for trend analysis in content identification based on fingerprinting. Assigned to Fraunhofer (DE), the second patent addresses techniques for calculating a fingerprint of an audio signal, apparatus and method for synchronizing and apparatus and method for characterizing a test audio signal
8,635,211, "Trend analysis in content identification based on fingerprinting," assigned to Dolby Labs.
Fingerprint-based content identification is described. Bin-counting detects linear trends based on data points that are generated from a set of query fingerprints, which are extracted from a query content item and a matching set of corresponding reference content items that are extracted from a reference content item. RANSAC may detect trends based on confidence scores that are computed for multiple candidate content items. The trends detected for the candidate content items are compared against a threshold in order of decreasing confidence score until a trend that satisfies the threshold is found. A ranking-based mechanism for fingerprint-based content identification may use a bin-counting or RANSAC-based trend detection mechanism to identify duplicate or multiple reference content items that all match the same query content item.
8,634,946, "Apparatus and method for calculating a fingerprint of an audio signal, apparatus and method for synchronizing and apparatus and method for characterizing a test audio signal," assigned to Fraunhofer Gesellschaft zur Foerderung der Angewandten Forschung E.V. (DE)
For calculating a fingerprint of an audio signal, the audio signal is divided into subsequent blocks of samples. For the subsequent blocks, one fingerprint value each is calculated, wherein fingerprint samples of subsequent blocks are compared. Based on whether the fingerprint value of a block is higher than the fingerprint value of a subsequent block or not, a binary value is assigned, wherein information about a sequence of binary values is output as fingerprint for the audio signal.