Method of extracting digital watermark information and method of judging bit value of digital watermark information
First Claim
1. A digital watermark information extracting method in which digital watermark information is extracted from image data which has the digital watermark information embedded therein by altering at least one pixel data located at a predetermined position on a specific coordinate end is geometrically deformed, comprising:
- an embedding position check step of performing the processing of extracting at least one pixel data at a predetermined position on the specific coordinate from the image data and comparing the data value of the pixel data thus extracted with a reference value to judge whether the information is embedded in the pixel data while applying the geometrical deformation on the image data until it is confirmed that the information is embedded in the pixel data, wherein said embedding position check step comprises;
a roughly checking step of executing the processing of extracting from the image data at least one pixel data located at a predetermined position on the specific coordinate and comparing the data value of the pixel data thus extracted with the reference value to judge whether the information is embedded in the pixel data concerned while the geometrical deformation is applied to the image data by every first geometrical deformation rate that the information is embedded in the pixel data concerned, a detailed checking step of executing the processing of extracting from the image data at least one pixel data located at a predetermined position on the specific coordinate and comparing the data value thus extracted with the reference value to judge whether the information is embedded in the pixel data concerned while the geometrical deformation is applied to the image data by every second geometrical deformation rate smaller than the first geometrical deformation rate within a predetermined range containing the geometrical deformation rate when it is confirmed in said roughly checking step that the information is embedded in the pixel data, until it is confirmed that the information is embedded in the pixel data concerned, a restoration step of restoring the image data referring to the deformation rate when it is confirmed that the information is embedded in the pixel data in the detailed checking step, and an extraction step of extracting the information thus embedded from the image data restored in the restoration step.
3 Assignments
0 Petitions
Accused Products
Abstract
A digital watermark information is extracted from geometrically deformed image without using a calibrating digital watermark. Pixel data at positions predetermined in an X-Y coordinate used when embedding the watermark is extracted from image data in which the digital watermark has been embedded for given pixel data and compared with a reference value to determine whether the watermark has been embedded in the pixel data concerned or not. This processing is repeated until it is confirmed that the information is embedded in the pixel data concerned, while applying geometric deformation to the image data.
-
Citations
6 Claims
-
1. A digital watermark information extracting method in which digital watermark information is extracted from image data which has the digital watermark information embedded therein by altering at least one pixel data located at a predetermined position on a specific coordinate end is geometrically deformed, comprising:
-
an embedding position check step of performing the processing of extracting at least one pixel data at a predetermined position on the specific coordinate from the image data and comparing the data value of the pixel data thus extracted with a reference value to judge whether the information is embedded in the pixel data while applying the geometrical deformation on the image data until it is confirmed that the information is embedded in the pixel data, wherein said embedding position check step comprises;
a roughly checking step of executing the processing of extracting from the image data at least one pixel data located at a predetermined position on the specific coordinate and comparing the data value of the pixel data thus extracted with the reference value to judge whether the information is embedded in the pixel data concerned while the geometrical deformation is applied to the image data by every first geometrical deformation rate that the information is embedded in the pixel data concerned, a detailed checking step of executing the processing of extracting from the image data at least one pixel data located at a predetermined position on the specific coordinate and comparing the data value thus extracted with the reference value to judge whether the information is embedded in the pixel data concerned while the geometrical deformation is applied to the image data by every second geometrical deformation rate smaller than the first geometrical deformation rate within a predetermined range containing the geometrical deformation rate when it is confirmed in said roughly checking step that the information is embedded in the pixel data, until it is confirmed that the information is embedded in the pixel data concerned, a restoration step of restoring the image data referring to the deformation rate when it is confirmed that the information is embedded in the pixel data in the detailed checking step, and an extraction step of extracting the information thus embedded from the image data restored in the restoration step.
-
-
2. A digital watermark information extracting method in which digital watermark information is extracted from image data which has the digital watermark information embedded therein by altering at least one pixel data located at a predetermined position on a specific coordinate and is geometrically deformed, comprising:
-
an embedding position check step of executing the processing of extracting at east one pixel data located at a predetermined position on the specific coordinate and comparing the data value of the pixel data thus extracted with a reference value to judge whether the information is embedded in the pixel data concerned while varying the predetermined position on the image data by deforming the specific coordinate until it is confirmed that the information is embedded in the pixel data concerned, wherein said embedding position check step comprises;
a roughly checking step of executing the processing of extracting from the image data at least one pixel data located at a predetermined position on the specific coordinate and comparing the data value of the pixel data thus extracted with the reference value to judge whether the information is embedded in the pixel data concerned while the predetermined position on the image data is varied by deforming the specific coordinate by every first deformation rate that the information is embedded in the pixel data concerned, a detailed checking step of executing the processing of extracting from the image data at least one pixel data located at a predetermined position on the specific coordinate and comparing the data value of the pixel data thus extracted with the reference value to judge whether the information is embedded in the pixel data concerned while the predetermined position on the image data is varied by deforming the specific coordinate by every second deformation rate smaller than the first deformation rate within a predetermined range containing the deformation rate when it is confirmed in said roughly checking step that the information is embedded in the pixel data concerned, a restoration step of restoring the image data referring to the deformation rate when it is confirmed that the information is embedded in the pixel data in the detailed checking step, and an extraction step of extracting the information thus embedded from the image data restored in the restoration step.
-
-
3. A storage medium for storing therein a digital watermark information extracting program for extracting digital watermark information from image data in which the digital watermark information is embedded by altering at least one pixel data located at a predetermined position on a specific coordinate and which is geometrically deformed, wherein said program when executed cause an information processor to perform:
-
an embedding position check step of performing the processing of extracting at least one pixel data at a predetermined position on the specific coordinate from the image data and comparing the data value of the pixel data thus extracted with a reference value to judge whether the information is embedded in the pixel data while applying the geometrical deformation on the image data until it is confirmed that the information is embedded in the pixel data, wherein said embedding position check step comprises;
a roughly checking step of executing the processing of extracting from the image data at least one pixel data located at a predetermined position on the specific coordinate and comparing the data value of the pixel data thus extracted with the reference value to judge whether the information is embedded in the pixel data concerned while the geometrical information is applied to the image data by every first geometrical deformation rate that the information is embedded in the pixel data concerned, and a detailed checking step of executing the processing of extracting from the image data at least one pixel data located at a predetermined position on the specific coordinate and comparing the data value thus extracted with the reference value to judge whether the information is embedded in the pixel data concerned while the geometrical deformation is applied to the image data by every second geometrical deformation rate smaller than the first geometrical deformation rate within a predetermined range containing the geometrical deformation rate when it is confirmed in said roughly checking step that the information is embedded in the pixel data, until it is confirmed that the information is embedded in the pixel data concerned, a restoration step of restoring the image data, referring to the deformation rate when it is confirmed that the information is embedded in the pixel data in the detailed checking step, and an extraction step of extracting the information thus embedded from the image data restored in the restoration step.
-
-
4. A storage medium for storing therein a digital watermark information extracting program for extracting digital watermark information from image data in which the digital watermark information is embedded by altering at least one pixel data located at a predetermined position on a specific coordinate and which is geometrically deformed, wherein said program when executed causes an information processor to perform:
-
an embedding position check step of performing the processing of extracting at least one pixel data at a predetermined position on the specific coordinate from the image data and comparing the data value of the pixel data thus extracted with a reference value to judge whether the information is embedded in the pixel data while the predetermined position on the image data is varied by deforming the specific coordinate until it is confirmed that the information is embedded in the pixel data, wherein said embedding position check step comprises;
a roughly checking step of executing the processing of extracting from the image data at least one pixel data located at a predetermined position on the specific coordinate and comparing the data value of the pixel data thus extracted with the reference value to judge whether the information is embedded in the pixel data concerned, while changing said predetermined position in the image data by effecting the deformation applied to the specific coordinate by every first deformation rate that the information is embedded in the pixel data concerned, and a detailed checking step of executing the processing of extracting from the image data at least one pixel data located at a predetermined position on the specific coordinate and comparing the data value thus extracted with the reference value to judge whether the information is embedded in the pixel data concerned while changing the predetermined position on the image data by effecting deformation applied to the image data by every second deformation rate smaller than the first deformation rate within a predetermined range containing the deformation rate when it is confirmed in said roughly checking step that the information is embedded in the pixel data, a restoration step of restoring the image data, referring to the deformation rate when it is confirmed that the information is embedded in the pixel data in the detailed checking step, and an extraction step of extracting the information thus embedded from the image data restored in the restoration step.
-
-
5. A digital watermark information extracting device for extracting digital watermark information from image data which has the digital watermark information embedded therein by altering at least one pixel data located at a predetermined position on a specific coordinate and is geometrically deformed, comprising:
-
means for performing the processing of extracting at least one pixel data at a predetermined, position on the specific coordinate from the image data and comparing the data value of the pixel data thus extracted with a reference value to judge whether the information is embedded in the pixel data while applying the geometrical deformation on the image data until it is confirmed that the information is embedded in the pixel data, wherein said means for performing comprises;
first means for executing the processing of extracting from the image data at least one pixel data located at a predetermined position on the specific coordinate and comparing the data value of the pixel data thus extracted with the reference value to judge whether the information is embedded in the pixel data concerned while the geometrical deformation is applied to the image data by every first geometrical deformation rate that the information is embedded in the pixel data concerned, second means for executing the processing of extracting from the image data at least one pixel data located at a predetermined position on the specific coordinate and comparing the data value thus extracted with the reference value to judge whether the information is embedded in the pixel data concerned while the geometrical deformation is applied to the image data by every second geometrical deformation rate smaller than the first geometrical deformation rate within a predetermined range containing the geometrical deformation rate when it is confirmed by said first means that the information is embedded in the pixel data, third means for restoring the image data referring to the deformation rate when it is confirmed that the information is embedded in the pixel data in said second means, and fourth means for extracting the information thus embedded from the image data restored in said third means.
-
-
6. A digital watermark information extracting device for extracting digital watermark information from image data which has the digital watermark information embedded therein by altering at least one pixel data located at a predetermined position on a specific coordinate and is geometrically deformed, comprising:
-
means for executing the processing of extracting at least one pixel data located at a predetermined position on the specific coordinate and comparing the data value of the pixel data thus extracted with a reference value to judge whether the information is embedded in the pixel data concerned while varying the predetermined position on the image data by deforming the specific coordinate until it is confirmed that the information is embedded in the pixel data concerned, wherein said means for executing comprises;
first means for executing the processing of extracting from the image data at least one pixel data located at a predetermined position on the specific coordinate and comparing the data value of the pixel data thus extracted with the reference value to judge whether the information is embedded in the pixel data concerned, while changing said predetermined position in the image data by effecting the deformation applied to the specific coordinate by every first deformation rate that the information is embedded in the pixel data concerned, second means for executing the processing of extracting from the image data at least one pixel data located at a predetermined position on the specific coordinate and comparing the data value thus extracted with the reference value to judge whether the information is embedded in the pixel data concerned while changing the predetermined position on the image data by effecting deformation applied to the image data by every second deformation rate smaller than the first deformation rate within a predetermined range containing the deformation rate when it is confirmed in said first means that the information is embedded in the pixel data, third means for restoring the image data referring to the deformation rate when it is confirmed that the information is embedded in the pixel data in said second means, and fourth means for extracting the information thus embedded from the image data restored in said third means.
-
Specification