Content Processing Methods Using Reversible Watermarking
AssigneeDigimarc Corporation
InventorsJun Tian, John Stach, Neil E. Lofgren
Life of this patent
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Abstract
The ability to remove a watermark from encoded content (e.g., an image) opens the possibility of various novel applications. Several such applications are detailed. One employs a reversible watermark in conjunction with a second (robust) watermark. In this arrangement, the payload of the reversible watermark conveys information about the robust watermark (e.g., encoding parameters, or an error signal), permitting removal of the robust watermark from an uncorrupted encoded image. By such arrangements, the encoded image can be fully restored to its pristine, unencoded state even if several different watermarks have been applied.
Claims25
A method comprising encoding a content object with a first digital watermark, the first watermark conveying a first payload of plural digital symbols, the first watermark being decodable notwithstanding at least certain corruptions of the encoded object, the payload including first data useful in characterizing changes made to the content object by encoding the first watermark therein so that such changes can later be reversed.
A method comprising:
- decoding a steganographic watermark from a watermark-encoded content object, the watermark conveying plural-symbol payload data, said payload data including first data that partially characterizes changes made to the content object by encoding the first watermark therein;
- by reference to said first data, producing a version of said content object having the watermark encoding substantially removed.
A method comprising:
- encoding a content object with a first digital watermark, the first watermark conveying a first payload of plural digital symbols, the first watermark being decodable notwithstanding at least certain corruptions of the encoded object;
- and
- transmitting first data to a second processor, the first data including data that partially characterizes changes made to the content object by encoding the first watermark therein, the first data being useful in substantially removing the first digital watermark from the encoded object at said second processor.
A method of making available a content object at different quality levels to different recipients, comprising:
- receiving an input content object;
- encoding the content object with plural digital watermarks, each watermark contributing distortion, each watermark being removable from the encoded content object through use of key data associated therewith;
- and
- distributing the watermarked content object to first and second recipients;
- wherein through use of first key data, the first recipient can remove a first watermark from the content object, thereby removing distortion associated with said first watermark, and through use of second key data, the second recipient can remove a second watermark from the content object, thereby removing distortion associated with said second watermark;
- wherein the different recipients can process the watermarked content object with different key data to yield content objects of different quality.
A method of making available a content object at different quality levels to different recipients, comprising:
- providing the same watermark-encoded content object to first and second recipients;
- through use of first key data associated with the first recipient, removing a first watermark from the encoded content object, thereby providing the first recipient a version of the content object having distortion associated with the first watermark removed therefrom;
- through use of second key data associated with the second recipient, removing a second watermark from the encoded content object, thereby providing the second recipient a version of the content object having distortion associated with the second watermark removed therefrom;
- wherein the different recipients process the watermarked content object with different key data to yield content objects of different quality.
A method of making available different versions of a content object to different recipients, comprising:
- providing the same content object to first and second recipients, said content object having at least a portion thereof of impaired quality, said content object being encoded with a plural-bit digital watermark;
- the first recipient using first key data to access first payload data from the digital watermark, the first payload data comprising information useful in ameliorating said impairment, said first key data not being available to the second recipient;
- and
- using said information, ameliorating the impairment in the content object provided to the first recipient;
- wherein the first and second recipients are provided different versions of the content object.
A method comprising:
- encoding a content object with a first, robust digital watermark, the first watermark conveying a first payload of one or more digital symbols, the first watermark being decodable notwithstanding at least certain corruptions of the encoded object;
- encoding the content object with a second digital watermark, the second watermark conveying a second payload of one or more digital symbols, the second watermark being encoded using a process that is reversible given an uncorrupted encoded content object and the second payload;
- wherein said payloads permit substantial removal of both watermarks from an uncorrupted version of the encoded content object.
A method comprising:
- receiving an uncorrupted content object encoded with first and second digital watermarks, the first and second watermarks conveying first and second payloads, respectively, the first watermark being of a type permitting decoding of the first payload notwithstanding at least certain corruptions of the encoded object;
- decoding the first and second watermarks to obtain the first and second payloads;
- and
- using said payloads to substantially remove both the first and second watermarks from the content object.
Dependencies are inferred from the claim text.