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UBC Theses and Dissertations
Wavelet packets-based digital watermarking for image authentication Paquet, Alexandre
Abstract
The rapid expansion of the Internet and the overall development of digital technologies in the past years have sharply increased the availability of digital media. Digital contents can be reproduced without loss of quality, but they may also be easily modified, and sometimes, imperceptibly. In many contexts, any alteration of image, video or audio data must be detected. Therefore, some work needs to be done to develop security systems to protect the content of digital data. Watermarking is accepted as a plausible candidate for such an application as it allows for the invisible insertion of information in a host by its imperceptible modification. This thesis is concerned with the protection of information contained in digital images. A novel, semi-fragile watermarking technique for the authentication of images is developed. Image protection is achieved by the insertion of a secret author's identification key in an image's wavelet packet (WP) decomposition. Rounding the mean of selected regions of WP coefficients embeds the binary key. To take maximum advantage of the host image's characteristics in the embedding process, an optimal quantization protocol is formulated. The image's verification is done without the use of the original unmarked image. The detection of unauthorized frequency or spatial tampering with the image is performed by a combined interband/intraband verification protocol. This new technique can detect malicious tampering with images, but stays unaffected by high quality JPEG compression.
Item Metadata
Title |
Wavelet packets-based digital watermarking for image authentication
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Creator | |
Publisher |
University of British Columbia
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Date Issued |
2002
|
Description |
The rapid expansion of the Internet and the overall development of digital
technologies in the past years have sharply increased the availability of digital media.
Digital contents can be reproduced without loss of quality, but they may also be
easily modified, and sometimes, imperceptibly. In many contexts, any alteration of
image, video or audio data must be detected. Therefore, some work needs to be done
to develop security systems to protect the content of digital data. Watermarking is
accepted as a plausible candidate for such an application as it allows for the invisible
insertion of information in a host by its imperceptible modification.
This thesis is concerned with the protection of information contained in digital
images. A novel, semi-fragile watermarking technique for the authentication of
images is developed. Image protection is achieved by the insertion of a secret author's
identification key in an image's wavelet packet (WP) decomposition. Rounding
the mean of selected regions of WP coefficients embeds the binary key. To
take maximum advantage of the host image's characteristics in the embedding process,
an optimal quantization protocol is formulated. The image's verification is
done without the use of the original unmarked image. The detection of unauthorized
frequency or spatial tampering with the image is performed by a combined
interband/intraband verification protocol. This new technique can detect malicious
tampering with images, but stays unaffected by high quality JPEG compression.
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Extent |
6325205 bytes
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Genre | |
Type | |
File Format |
application/pdf
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Language |
eng
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Date Available |
2009-09-29
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Provider |
Vancouver : University of British Columbia Library
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Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
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DOI |
10.14288/1.0065184
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URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
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Graduation Date |
2002-11
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Campus | |
Scholarly Level |
Graduate
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Aggregated Source Repository |
DSpace
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Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.