On Thursdays the USPTO publishes new pending patent applications. Both of today's Spotlight Applications concern aspects of digital watermarking. Assigned to Dolby Labs, the first application discloses techniques for replacement based watermarking. Assigned to Philips, the second application discloses techniques for watermark embedding using lookup tables.
20090136087, "Replacement Based Watermarking," assigned to Dolby Laboratories, Inc.
Abstract
A video processor for replacement based watermarking may include a video content input channel; a video content preprocessor; a replacement based watermarking (RBW) metadata creator; and a video content encoder. To output the encoded video content, the video processor may have a dual or single output channel. For a dual output channel, the video processor includes an encoded video content output channel and an RBW metadata output channel for outputting encoded video content and RBW metadata as separate streams for further processing and distribution. For a single output channel, the video processor includes a video content output channel for outputting encoded video content combined with RBW metadata as a single output stream for further processing and distribution.20090136026, "Watermark Embedding Using Look-Up Tables," assigned to Philips.
Abstract
The invention relates to embedding a spread spectrum watermark in a data signal as well as to detection of the embedded watermark. A data signal (4) is encrypted (15) or received in the form of an encrypted data signal (9), the signal being encrypted by modifying (3) it in accordance with one or more entries of a look-up-table (2) in which an encryption table (6) is stored. The encryption is carried out by a first computing device (15) such as a server device. The watermark is actually embedded while decrypting (13) the signal. This takes place in a second computing device (16), possibly in a client device, in a similar manner The client device employs a decryption table (8), which is a modified (i.e. watermarked) version of the encryption table (6). The decryption table may generated by the server and securely communicated to the client. The data signal is decrypted in accordance with entries of a look-up-table (12). The look-up-tables (2,12) in server and client are addressed by the same sequence of pointers generated by respective index generators (1). The mismatch between encryption table (6) and decryption table (8) causes the de-signal (14) to have an embedded watermark.
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