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US 7,065,226 B1Granted
Method for embedding information and extracting the same
AssigneeHitachi, Ltd.
InventorsKousuke Anzai, Isao Echizen, Hiroshi Yoshiura, Shinobu Eikawa
Life of this patent
Estimating the term…
Abstract
A method of embedding digital watermark information b1–bn (2≦n) in image data. The image data is divided into a plurality of areas S each consisting of M×N (1≦M, N) pixels. A plurality of areas G each consisting of P×Q (1≦P, Q) of the areas S are defined. Each of the areas S constituting each area G is allocated to some one of: areas T1–Tn in which said digital watermark information b1–bn is respectively embedded and areas H1–Hm (1≦m) in which information is not embedded. One or more areas T and one or more areas H are located in a predetermined arrangement in each area G. And, the plurality of areas G are located in a predetermined rule.
Claims6
A method of embedding digital watermark information b1–bn (2≦n) in image data, comprising the steps of:
- dividing the image data into a plurality of areas S each consisting of M×N (1≦M, N) pixels;
- defining an area G consisting of P×Q (1≦P, Q) of the areas S;
- allocating each of the areas S constituting said area G to some one of:
- areas T1–Tn whose pixel values are changed, areas J1–Jk (1≦k) in which information p1–pk (1≦k) specifying an embedding format for embedding said digital watermark information b1–bn in said areas T1–Tn, and areas H1–Hm (1≦m) whose pixel values are not changed;
- corresponding each of said T1–Tn, whose pixel values are changed, to each of said digital watermark information b1–bn and changing the pixel value of each area T according to a bit value;
- locating areas T1–Tn, areas J1–Jk and areas H1–Hm in a predetermined same arrangement in said area G;
- and
- locating said area G repeatedly over entire image data,
- wherein:
- said digital watermark information b1–bn is embedded by increasing or decreasing pixel data values in the corresponding areas T1–Tn according to a bit value (0, 1) of each bit of the digital watermark information b1–bn;
- and
- said information p1–pk specifying said embedding format is embedded such that said information indicates a pattern of respective increasing/decreasing directions in the area T1–Tn for a bit value of the digital watermark information, in each area G to which the area J1–Jk embedded with said information p1–pk belong.
9 more elements
A method of extracting digital watermark information, for extracting the digital watermark information b1–bn (2≦n), a bit value of the digital watermark information being 0 or 1, from image data in which said digital watermark information is embedded, comprising steps of:
- dividing the image data into a plurality of areas S each consisting of M×N (1≦M, N) pixels;
- detecting areas H1–Hm (1≦m) in which any of bit information 0 and 1 is not embedded, from said plurality of areas S;
- recognizing a plurality of areas G each consisting of P×Q (1≦P, Q) of the areas S, said plurality of areas G being located on said image data, and said recognition being carried out by comparing locations of said detected areas H1–Hm on said image data and locations of predetermined areas H1–Hm in the areas S;
- in each of the plurality of areas G recognized, extracting information p1–pk (1≦k) from areas J1–Jk in which said information p1–pk (1≦k) in which said information p1–pk (1≦k) should be embedded, said information p1–pk specifying an embedding format for embedding said digital watermark information b1–bn respectively in said areas T1–Tn;
- recognizing the embedding format of the digital watermark information b1–bn in the areas T1–Tn in the areas G in question;
- and
- extracting the digital watermark information b1–bn from the areas T1–Tn, according to the recognized embedding format,
- wherein:
- for each of the plurality of groups G recognized, the information p1–pk embedded in the areas J1–Jk is extracted to recognize a pattern of increasing/decreasing directions of pixel data values for a bit value of the digital watermark information, in the area G in question;
- and
- each bit value of the digital watermark information b1–bn embedded in the areas T1–Tn is detected according to the recognized pattern of increasing/decreasing directions.
8 more elements
A program product for making a computer execute a method of embedding digital watermark information b1–bn (2≦n) in image data, comprising:
- codes for dividing the image data into a plurality of areas S each consisting of M×N (1≦M, N) pixels;
- codes for defining an area G consisting of P×Q (1≦P, Q) of the areas S;
- codes for allocating each of the areas S constituting said area G to some one of:
- areas T1–Tn whose pixel values are changed, areas J1–Jk (1≦k) in which information p1–pk (1≦k) specifying an embedding format for embedding said digital watermark information b1–bn, a bit value of the digital watermark information being 0 or 1, in said areas T1–Tn, and areas H1–Hm (1≦m) whose pixel values are not changed;
- codes for corresponding each of said T1–Tn whose pixel values are changed, to each of said digital watermark information b1–bn and changing the pixel value of each area T according to a bit value;
- codes for locating one or more areas T1–Tn, and areas J1–Jk in a predetermined same arrangement in said area G;
- codes for locating said area G repeatedly over entire image data;
- codes for embedding said digital watermark information b1–bn by increasing or decreasing pixel data values in the corresponding areas T1–Tn according to a bit value (0, 1) of each bit of the digital watermark information b1–bn;
- codes for embedding said information p1–pk specifying said embedding format such that said information indicates a pattern of respective increasing/decreasing directions in the areas T1–Tn for a bit value of the digital watermark information, in each area G to which the areas J1–Jk embedded with said information p1–pk belong;
- and
- a computer readable storage medium for holding the codes.
8 more elements
A program product for making a computer execute a method of extracting digital watermark information b1–bn (2≦n), a bit value of the digital watermark information being 0 or 1, from image data in which said digital watermark information is embedded, comprising:
- codes for dividing the image data into a plurality of areas S each consisting of M×N (1≦M, N) pixels;
- codes for detecting areas H1–Hm (1≦m) in which any of bit information 0 and 1 is not embedded, from said plurality of areas S codes for recognizing a plurality of areas G each consisting of P×Q (1≦P, Q) of the areas S, said plurality of areas G being located on said image data, and said recognition being carried out by comparing locations of said detected areas H1–Hm on said image data and locations of predetermined areas H1–Hm in the areas S;
- codes for extracting, in each of the plurality of areas G recognized, information p1–pk (1≦k) from areas J1–Jk in which said information p1–pk (1≦k) should be embedded, said information p1–pk specifying an embedding format for embedding said digital watermark information b1–bn respectively in said areas T1–Tn;
- codes for recognizing the embedding format of the digital watermark information b1–bn in the areas T1–Tn in the area G in question;
- codes for extracting the digital watermark information b1–bn from the areas T1–Tn according to the recognized embedding format;
- codes for extracting, for each of the plurality of groups G recognized, the information p1–pk embedded in the areas J1–Jk to recognize a pattern of increasing/decreasing directions of pixel data values for a bit value of the digital watermark information, in the area G in question, and to detect each bit value of the digital watermark information b1–bn embedded in the areas T1–Tn according to the recognized pattern of increasing/decreasing directions;
- and
- a computer readable storage for holding the codes.
5 more elements
An apparatus for embedding digital watermark information b1–bn (2≦n) in image data, comprising:
- a processing part for dividing the image data into a plurality of areas S each consisting of M×N (1≦M, N) pixels;
- a processing part for defining an area G consisting of P×Q (1≦P, Q) of the areas S;
- a processing part for allocating each of the areas S constituting said area G to some one of:
- areas T1–Tn whose pixel values are changed, areas J1–Jk (1≦k) in which information p1–pk (1≦k) specifying an embedding format for embedding said digital watermark information b1–bn in said areas T1–Tn, and areas H1–Hm (1≦m) whose pixel values are not changed;
- a processing part for corresponding each of said T1–Tn whose pixel values are changed, to each of said digital watermark information b1–bn and changing the pixel value of each area T according to a bit value;
- a processing part for locating one or more areas T1–Tn, one or more areas J1–Jk and one or more areas H1–Hm in a predetermined same arrangement in said area G;
- a processing part for locating said area G repeatedly over entire image data;
- a processing part for embedding said digital watermark information b1–bn by increasing or decreasing pixel data values in the corresponding areas T1–Tn according to a bit value (0, 1) of each bit of the digital watermark information b1–bn;
- and
- a processing part for embedding said information p1–pk specifying said embedding format such that said information indicates a pattern of respective increasing/decreasing directions in the area T1–Tn for a bit value of the digital watermark information, in each area G to which the areas J1–Jk embedded with said information p1–pk belong.
7 more elements
An apparatus for extracting digital watermark information b1–bn (2≦n), a bit value of the digital watermark information being 0 or 1, from image data in which said digital watermark information is embedded, comprising:
- a processing part dividing the image data into a plurality of areas S each consisting of M×N (1≦M, N) pixels;
- a processing part for detecting areas H1–Hm (1≦m) in which any of bit information 0 and 1 is not embedded, from said plurality of areas S;
- a processing part for recognizing a plurality of areas G each consisting of P×Q (1≦P, Q) of the areas S, said plurality of areas G being located repeatedly over entire said image data, and said recognition being carried out by comparing locations of said detected areas H1–Hm on said image data and locations of predetermined areas H1–Hm in the areas S;
- a processing part for extracting, in each of the plurality of areas G recognized, information p1–pk (1≦k) from areas J1–Jk in which said information p1–pk (1≦k) should be embedded, said information p1–pk specifying an embedding format for embedding said digital watermark information b1–bn respectively in said areas T1–Tn;
- a processing part for recognizing the embedding format of the digital watermark information b1–bn in the areas T1–Tn in the area G in question;
- a processing part for extracting the digital watermark information b1–bn from the areas T1–Tn, according to the recognized embedding format;
- and
- a processing part for extracting, for each of the plurality of groups G recognized, the information p1–pk embedded in the areas J1–Jk, to recognize a pattern of increasing/decreasing directions of pixel data values for a bit value of the digital watermark information, in the area G in question, and to detect each bit value of the digital watermark information b1–bn embedded in the areas T1–Tn, according to the recognized pattern of increasing/decreasing directions.
5 more elements
Dependencies are inferred from the claim text.