Digital Watermark Systems and Methods
AssigneeDigimarc Corporation
InventorsAndrew Johnson, Michael Biggar
Life of this patent
Estimating the term…
Abstract
A digital watermark is added to audio or visual content. An illustrative embodiment permutes the content, alters the permuted content to encode a watermark, and inverse-permutes the content to return same to substantially its original form. Related watermark decoding methods are also detailed, as are ancillary features and techniques
Claims18
A monitoring method, for determining a source of audio data, comprising:
- receiving audio data, and storing one or more blocks of same in a buffer;
- decoding plural-bit message data encoded as slight changes in the data, said decoding including detecting synchronization information that signals a beginning of the message data;
- performing a comparison operation between the decoded plural-bit message data and previously-stored data;
- and
- indicating, based on the foregoing, a source of the audio data.
A monitoring method, for determining a source of video data, comprising:
- receiving video data, and storing one or more blocks of same in a buffer;
- decoding plural-bit message data encoded as slight changes in the data, said decoding including detecting synchronization information that signals a beginning of the message data;
- performing a comparison operation between the decoded plural-bit message data and previously-stored data;
- and
- indicating, based on the foregoing, a source of the video data.
A method of encoding a sequence of image frames with a complete digital watermark message, comprising:
- receiving a sequence of image frames;
- segmenting each of plural of said frames into plural blocks;
- encoding first and second blocks of a first frame with a first portion of said digital watermark message;
- and
- encoding first and second blocks of a further frame with a different portion of said digital watermark message;
- wherein the complete digital watermark message is not encoded in a single frame, but rather is distributed over plural frames of said sequence.
A method of processing content data to extract digital watermark data therefrom, the content data comprising plural samples, each sample having a value, the method including the acts:
- identifying a group of samples;
- determining a mean value of said group of samples;
- subtracting said determined mean value from the value of each of said samples in the group, to yield a set of mean-removed sample values;
- and
- extracting digital watermark data based on said set of mean-removed sample values.
A method of watermark processing comprising:
- receiving a set of content data;
- and
- processing same to either embed a watermark therein, or extract a watermark therefrom, in accordance with an algorithm;
- wherein the method includes changing a keying parameter of said algorithm during processing of said content data.
A method of watermark processing that includes the acts:
- receiving content data representing audio, image or video information;
- permuting at least some of the content data to scramble same;
- altering the content data following said permuting to represent watermark data therein;
- and
- inverse-permuting the content data following said altering.
A method of watermark processing that includes the acts:
- receiving content data representing audio, image or video information;
- permuting at least some of the content data;
- and
- decoding watermark data from the content data following said permuting.
Dependencies are inferred from the claim text.