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US 7,116,781 B2Granted
Counteracting geometric distortions in watermarking
AssigneeDigimarc Corporation
InventorGeoffrey B. Rhoads
Life of this patent
Estimating the term…
Abstract
A digital watermarking method receives multimedia data, such as images or audio, in compressed or uncompressed form, and extracts a digital watermark while counteracting geometric distortions. To counteract geometric distortion, a watermark reading process translates the data before extracting the digital watermark. The reading process operates on compressed data such as JPEG or MPEG images, which are comprised of compressed blocks of image data.
Claims10
A method for exacting a watermark from data containing a watermark comprising:
- receiving data containing a watermark including a plural-bit message and at least one steganographic component;
- with reference to the steganographic component, determining a registration associated with the data or component;
- and
- extracting the plural-bit message of the watermark with at least consideration of the registration.
1 more element
A method of extracting a watermark from compressed data containing a watermark comprising:
- receiving compressed data containing a watermark in the form of n by n blocks, which data has been subjected to distortion;
- transforming the data;
- determining a calibration of the transformed data based on characteristics of a steganographic calibration component associated with the watermark;
- and
- extracting the watermark from the transformed data based at least in part on the calibration.
2 more elements
Dependencies are inferred from the claim text.