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.
Claims47
A method for extracting a watermark from compressed data containing a watermark comprising the steps of:
- receiving compressed data containing a watermark in the form of n by n blocks of data subjected to affine geometric distortion;
- spatially translating the blocks according to a spatially varying translation to compensate for an assumed affine geometric distortion;
- and
- extracting the watermark from the translated blocks of data.
A method of extracting a watermark from compressed data containing a watermark comprising the steps of:
- receiving compressed data containing a watermark in the form of blocks, which data has been subjected to affine geometric distortion;
- accumulating said blocks in a set of a predetermined number of groups of 8 by 8 blocks;
- converting the accumulated blocks into spatial domain;
- spatially translating the spatial domain accumulated blocks to compensate for an assumed affine geometric distortion;
- summing the translated blocks;
- and
- extracting the watermark from the summed translated blocks.
A method of extracting a watermark from compressed data containing a watermark comprising the steps of:
- receiving compressed data containing a watermark in the form of n by n blocks, which data has been subjected to affine geometric distortion;
- accumulating said blocks in a set of a predetermined number of groups of n by n blocks;
- converting the accumulated blocks into spatial domain;
- spatially translating the spatial domain accumulated blocks to compensate for an assumed affine geometric distortion;
- summing the translated blocks;
- and
- extracting the watermark from the summed translated blocks.
A method for extracting a watermark from data containing a watermark comprising the steps of:
- receiving data containing a watermark, which data has been subjected to affine geometric distortion;
- accumulating said data as n by n blocks of data;
- spatially translating the blocks of data to compensate for affine geometric distortion;
- performing DCT transformation of said n by n blocks of data;
- and
- extracting the watermark from the translated blocks of transformed data.
A method for extracting a watermark from data containing a watermark comprising the steps of:
- receiving data containing a watermark, which data has been subjected to affine geometric distortion;
- accumulating said data into a predetermined number of n by n accumulated blocks of data according to a mapping algorithm of an assumed affine geometric distortion;
- and
- extracting the watermark from the accumulated blocks of data.
A method of extracting a watermark from compressed data containing a watermark comprising the steps of:
- receiving compressed data containing a watermark in the form of n by n blocks, which data has been subjected to affine geometric distortion;
- accumulating said blocks into a set of a predetermined number of groups of n by n accumulated blocks according to a mapping algorithm of an assumed affine geometric distortion;
- and
- extracting the watermark from the accumulated blocks.
A method of extracting a watermark from compressed data containing a watermark comprising the steps of:
- receiving compressed data containing a watermark in the form of blocks, which data has been subjected to affine geometric distortion;
- storing said blocks in a set of predetermined groups of 8 by 8 blocks;
- converting the blocks into spatial domain;
- spatially translating the spatial domain accumulated blocks to compensate for an assumed affine geometric distortion;
- and
- extracting the watermark from the translated blocks.
A method of extracting a watermark from compressed data containing a watermark comprising the steps of:
- receiving compressed data containing a watermark in the form of n by n blocks, which data has been subjected to affine geometric distortion;
- storing said blocks in a set of predetermined number of groups of n by n blocks
- converting the blocks into spatial domain;
- spatially translating the spatial domain accumulated blocks to compensate for an assumed affine geometric distortion;
- and
- extracting the watermark from the translated blocks.
A method for extracting a watermark from data containing a watermark comprising the steps of:
- receiving data containing a watermark, which data has been subjected to affine geometric distortion;
- storing said data as n by n blocks of data;
- spatially translating the blocks of data to compensate for affine geometric distortion;
- performing a transformation of said blocks of data;
- and
- extracting the watermark from the translated blocks.
A method for extracting a watermark from data containing a watermark comprising the steps of:
- receiving data containing a watermark, which data has been subjected to affine geometric distortion;
- storing said data into a predetermined number of n by n blocks of data according to a mapping algorithm of an assumed affine geometric distortion;
- and
- extracting the watermark from the accumulated blocks of data.
A method of extracting a watermark from compressed data containing a watermark comprising the steps of:
- receiving compressed data containing a watermark in the form of n by n blocks, which data has been subjected to affine geometric distortion;
- storing said blocks into a set of a predetermined number of groups of n by n blocks according to a mapping algorithm of an assumed affine geometric distortion;
- and
- extracting the watermark from the accumulated blocks.
Dependencies are inferred from the claim text.