Method and device for sending and receiving digital images using an image watermark for decoding
AssigneeCanon Kabushiki Kaisha
InventorsFrédérique Ehrmann Patin, Ioana Donescu
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Abstract
In order to decode a received digital signal which has been watermarked with a known watermark, at least part of the digital signal is decoded by using a parametrisable iterative decoder, the watermark is extracted from the decoded signal, the extracted watermark is compared with the known watermark, and at least one parameter of the decoder is modified if necessary, according to the result of the comparison.
Claims52
A method of sending a digital signal, comprising the steps of:
- inserting a watermark, which is known to a receiving end, in the digital signal, so as to obtain a watermarked digital signal;
- encoding the watermarked digital signal by means of an encoder, so as to obtain an encoded watermarked signal which can be decoded by means of a parametrisable iterative decoder;
- and
- sending the encoded, watermarked signal, wherein the sent, encoded watermarked signal is processable by the receiving end to obtain the watermark, to compare the obtained watermark to a known watermark, and to modify at least one parameter of the decoder according to a result of the comparison between the watermark obtained from the sent, encoded watermarked signal and the known watermark.
A device for sending a digital signal, comprising
- watermarking means for inserting a watermark, which is known to a receiving end, in the digital signal, said watermarking means outputting a watermarked digital signal;
- encoding means for encoding the watermarked digital signal by means of an encoder, said encoding means outputting an encoded watermarked signal decodable by means of a parameterisable iterative decoder;
- and
- sending means for sending said encoded watermarked signal, wherein the sent, encoded watermarked signal is processable by the receiving end to obtain the watermark, to compare the obtained watermark to a known watermark, and to modify at least one parameter of the decoder according to the result of the comparison between the watermark obtained from the sent, encoded watermarked signal and the known watermark.
A method of decoding a received digital signal, the digital signal having been watermarked with a known watermark, comprising the steps of:
- decoding at least part of the received digital signal by means of a parameterisable iterative decoder;
- extracting the watermark from the decoded signal;
- comparing the extracted watermark with a known watermark;
- and
- modifying, if necessary, at least one parameter of the decoder according to the result of the comparison in said comparing step.
A device for decoding a received digital signal, the digital signal having been watermarked with a known watermark, comprising:
- decoding means for decoding at least part of the digital signal by means of a parameterisable iterative decoder;
- watermark extracting means for extracting the watermark from the decoded signal;
- comparing means for comparing the extracted watermark with the known watermark;
- and
- modifying means for modifying, if necessary, at least one parameter of the decoding means according to the result of the comparison performed by said comparing means.
Dependencies are inferred from the claim text.