On Tuesdays the USPTO issues new patents. Today's Spotlight Patents concern aspects of digital fingerprinting and watermarking. Assigned to Landmark Digital Services, the first patent addresses techniques for robust and invariant audio pattern matching. Assigned to KDDI (JP), the second patent addresses techniques for digital watermarking and drift compensation.
Abstract
The present invention provides an innovative technique for rapidly and accurately determining whether two audio samples match, as well as being immune to various kinds of transformations, such as playback speed variation. The relationship between the two audio samples is characterized by first matching certain fingerprint objects derived from the respective samples. A set (230) of fingerprint objects (231,232), each occurring at a particular location (242), is generated for each audio sample (210). Each location (242) is determined in dependence upon the content of the respective audio sample (210) and each fingerprint object (232) characterizes one or more local features (222) at or near the respective particular location (242). A relative value is next determined for each pair of matched fingerprint objects. A histogram of the relative values is then generated. If a statistically significant peak is found, the two audio samples can be characterized as substantially matching.
7,627,135, "Digital watermarking system and drift compensating system," assigned to KDDI Corporation (JP).
Abstract
An object of the present invention is to perform DCT coefficient operation and drift compensation for embedding watermark data with the small amount of computing. An MB data extraction unit extracts a macro block or block into which the watermark data is embedded on the basis of a template. Additionally, a DCT coefficient extraction unit extracts the DCT coefficient at a position into which the watermark data is embedded according to a direction of the template. A DCT coefficient operation unit performs the process of embedding the watermark data or the process of compensating the drift to the extracted DCT coefficient.
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