Robust blind watermarking method in wavelet DC components
First Claim
1. A blind digital watermark embedding apparatus based on wavelet transform comprising:
- a high-frequency component removing unit for removing high-frequency components from a target image corresponding to a target domain of a wavelet-transformed original image in which watermarks are to be embedded, thereby generating a mirror image corresponding to the target domain free of high-frequency components;
an index information generating unit for generating index information representing pixel positions in the target domain where data of the watermarks are to be embedded, respectively;
a watermark generating unit for generating a data stream of the watermarks to be embedded in the target image; and
a watermark embedding unit for embedding the watermarks of the watermark data stream generated from the watermark generating unit in pixel data of the target image at the pixel positions determined based on the index information from the index information generating unit, respectively.
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Abstract
An apparatus and method for embedding and extracting digital watermarks using a blind mode based on wavelet transform which is robust to external attacks while being capable of minimizing a degradation in picture quality caused by embedding of the watermarks. In accordance with the invention, watermarks protection of the copyright for desired data are embedded in DC component domains of wavelet-transformed domains. In accordance with the invention, embedding of watermarks in a target image corresponding to a target domain in which the watermarks are to be embedded, is achieved by generating a data stream of the watermarks in accordance with a key value selected by the user, generating index information representing positions where the watermarks are to be embedded, in accordance with a key value selected by the ser, and reflecting the watermark data stream on data values of pixels in the target image at the positions based on the index information.
44 Citations
37 Claims
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1. A blind digital watermark embedding apparatus based on wavelet transform comprising:
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a high-frequency component removing unit for removing high-frequency components from a target image corresponding to a target domain of a wavelet-transformed original image in which watermarks are to be embedded, thereby generating a mirror image corresponding to the target domain free of high-frequency components;
an index information generating unit for generating index information representing pixel positions in the target domain where data of the watermarks are to be embedded, respectively;
a watermark generating unit for generating a data stream of the watermarks to be embedded in the target image; and
a watermark embedding unit for embedding the watermarks of the watermark data stream generated from the watermark generating unit in pixel data of the target image at the pixel positions determined based on the index information from the index information generating unit, respectively. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A blind digital watermark extracting apparatus based on wavelet transform comprising:
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a high-frequency component removing unit for removing high-frequency components from a target image corresponding to a target domain of a wavelet-transformed original image in which watermarks are to be embedded, thereby generating a mirror image corresponding to the target domain free of high-frequency components;
an index information generating unit for generating index information representing pixel positions in the target domain where data of the watermarks are to be embedded, respectively;
a watermark generating unit for generating a data stream of the watermarks to be embedded in the target image;
a watermark extracting unit for receiving the index information from the index information generating unit, receiving a watermark-embedded image corresponding to a watermark-embedded domain of the wavelet-transformed original image, and extracting a data stream of watermarks from in the watermark-embedded image, based on the index information; and
a watermark comparing unit for checking a similarity between the original watermark data stream from the watermark generating unit and the extracted watermark data stream from the watermark extracting unit, thereby determining whether or not the original watermarks are embedded in the wavelet-transformed original image. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A digital watermark embedding method in a wavelet-based blind digital watermark embedding apparatus including a high frequency removing unit, an index information generating unit, a watermark generating unit, and a watermark embedding unit, comprising the steps of:
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(a) executing a multi-level wavelet transform at a level corresponding to the size of a data stream of watermarks to be embedded, for an original image in which the watermarks are to be embedded, and setting a target domain of the wavelet-transformed image in which the watermarks are to be embedded;
(b) removing high-frequency components from a target image corresponding to the set target domain, thereby generating a mirror image corresponding to the target image, but free of high-frequency components;
(c) generating index information representing pixel positions in the target domain where data of the watermarks are to be embedded, respectively; and
(d) embedding the watermark data stream in pixel data of the target image at the pixel positions determined based on the index information, respectively. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30)
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31. A digital watermark extracting method in a wavelet-based blind digital watermark extracting apparatus including a high frequency removing unit, an index information generating unit, a watermark generating unit, a watermark extracting unit, and a watermark comparing unit, comprising the steps of:
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(a′
) generating position information about pixels in which a data stream of original watermarks has bee embedded, based on a target image corresponding to a target domain of a wavelet-transformed original image in which the original watermark data stream has been embedded;
(b′
) receiving data of pixels in the target domain in which the original watermark data stream has been embedded;
(c′
) extracting a watermark data stream from the received pixel data at positions determined based on the pixel position information; and
(d′
) checking a similarity between the original watermark data stream and the extracted watermark data stream, thereby determining whether or not the original watermarks are embedded in the wavelet-transformed original image. - View Dependent Claims (32, 33, 34, 35, 36, 37)
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Specification