Tuesdays the USPTO issues new patents. Today's Spotlight issued patents address watermarking and fingerprinting. Assigned to Philips, the first patent concerns techniques for watermarking. Assigned to Sony, the second patent concerns the use of fingerprinting in recognizing compact discs and issuing corresponding credits.
7,334,129,"Embedding supplemental data in an encoded signal," assigned to Philips.
There are two different methods of embedding supplemental data, e.g. for watermarking into an encoded signal.I. For an encoder, which needs auxiliary information for encoding (=probability information in this special case), the auxiliary information to encode the supplemental data is derived from data used otherwise in the encoding process. The advantage is that the derived auxiliary data does not have to be stored, so that embedding the supplemental data is economical with respect to the total amount of bits used.II. In the encoding process used for super Audio CD, a set of parameters (e.g. filter coefficients) is used by the encoder, whereby these parameters have to be stored, as they are needed for decoding. To embed supplemental data, at least one of the chosen parameters (e.g. the LSB of the first coefficient) is set to a dedicated value in response to the value of the supplemental data to be embedded. The advantage is that the bit rate will not be affected at all.
7,333,935, "Methods and apparatus for recognizing compact discs and issuing corresponding credits," assigned to Sony.
For possible use in an electronic content distribution system, automatic recognition of compact discs or other storage media containing particular content, and corresponding account crediting is described. In an electronic content distribution system, such as those providing music available by digital downloading or streaming technologies, a user may ordinarily pay a full price to receive the music. A user who possesses and apparently owns a compact disc containing particular content can be conveniently offered a discount or credit usable towards the purchase of the analogous particular content in a form provided by the electronic content distribution system. Preferably, compact discs are uniquely identified by determining whether their digital fingerprint matches a known reference fingerprint for a compact disc containing the particular content.