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|Title||Blind and Reversible Color Image Watermarking Schemes for Content Authentication and Copyright Protection|
The main contribution of this thesis is to detect any modification, forgery, or illegal manipulation in images, as well as distinguishing between malicious attacks and incidental manipulations. To achieve this goal, three schemes are proposed. The three proposed schemes are tested based on a dataset contains 1050 colored images divided into eleven categories. All tests are performed using a laptop with a 2 GHz core 2 duo processors, 2 GB memory, and 384 MB display adapter. Matlab 7.8 and Visual Studio 2011 are used in implementing the proposed schemes and counterparts. The first proposed scheme is the Content Authentication (CA) watermarking scheme, which is a fragile, blind, and reversible watermarking scheme; aimed at detecting manipulation in color images. It generates the watermark uniquely, using a messy model. The generated watermark is embedded accumulatively; to obtain spreading over whole image’s area, and homogeneously; to obtain a high quality watermarked image. Our proposed scheme is a development of a recently proposed watermarking scheme. Our proposed scheme surpassed its counterpart in terms of capacity, quality, watermark spreading, fragility, and embedding time. The payload of the host image increased from 81.71 % to 93.82 %. The minimum obtained PSNR value is increased from 27.15 dB to 31.76 dB. The watermark spreading percentage, or the percentage of the protected pixels, is noticeably increased. Our proposed scheme is very sensitive to modifications anywhere at the image, even if it is tiny. Finally, our proposed CA scheme is faster than its counterpart in embedding. We obtained an average reduction in time equals, 0.15 second. The second proposed scheme is the Copyright Protection (CP) watermarking scheme, which is a robust, blind, and reversible watermarking scheme; aimed at protecting the copyright of color images against geometrical attacks. It is also a development of an already existing watermarking scheme. Watermark embedding in this scheme, as well as in its counterpart, mainly depends on the permutation of histogram bins. But, we present a new embedding rule, which increased the average capacity by about 55 bits, and also it increased the quality, PSNR, of the watermarked image from 35.01 dB to 38.05 dB. The embedded watermark demonstrates 100 % robustness against a variety of geometrical attacks, like Flipping (H, V, and Both), Rotation (90°, 180°, and 270°), Scattering, Warping, Skewing, and their combinations. Finally, our proposed CP watermarking scheme showed a faster watermark embedding process than that of its counterpart by an average reduction in time equals, 4.84 seconds. The third proposed scheme is a blind and reversible multipurpose watermarking scheme, for both CA and CP of color images. It combines the first and the second proposed watermarking schemes, in a way, to fulfill the main contribution of this thesis. Experimental results showed that; despite of embedding two watermarks at the same host image, the generated watermarked images using this scheme are still having PSNR values of higher than 30 dB, the obtained average PSNR is 33.25 dB.
|Publisher||الجامعة الإسلامية - غزة|
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