On Tuesday's the USPTO issues new patents. Today's Spotlight Patents concern digital fingerprinting and digital watermarking. Assigned to Auditude, the first patent concern extraction and matching of characteristic fingerprints from audio signals. Assigned to Toshiba, the second patent concerns techniques for embedding and detecting digital watermarks.
An audio fingerprint is extracted from an audio sample, where the fingerprint contains information that is characteristic of the content in the sample. The fingerprint may be generated by computing an energy spectrum for the audio sample, resampling the energy spectrum logarithmically in the time dimension, transforming the resampled energy spectrum to produce a series of feature vectors, and computing the fingerprint using differential coding of the feature vectors. The generated fingerprint can be compared to a set of reference fingerprints in a database to identify the original audio content.
7,515,731, "Digital watermark embedding apparatus and digital watermark detecting apparatus," assigned to Toshiba (JP).
A digital watermark embedding apparatus includes a detector detecting a signal characteristic of at least one of an input image signal and the output image signal, and a controller controlling an embedding intensity of a digital watermark signal with respect to the input image signal in accordance with the signal characteristic.