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G.S.El-Taweel,
H.M. Onsi, M.Samy, M.G. Darwish
Faculty
of Computers and Information,
Abstract:
This paper represents
secure watermarking scheme for color images, providing
robustness against a set of attacks. Firstly, the image
is transformed using an appropriate color transformation.
Next each of color channels is transformed through Discrete
Wavelet Transform (DWT) and then the Discrete Hadamard
Transform (DHT) is applied. By this cascaded transformation,
we are in a position to select the most appropriate coefficients,
which are close to the low and middle frequencies and
uncorrelated in nature. Higher level of security is achieved
by introducing encryption among the selected transformed
coefficients using a private encryption key. Secondly,
we propose non-blind detection scheme. Original image
is mandatory, which is based on other widely known watermark
detection techniques, but has some modifications. The
results are two-stages, multi-resolution watermark decoder
that allows efficient identification of the embedded watermarking
key without prior notice. The scheme is tested against
a variety of legitimate and illicit image processing operations
including compression, uniform and Gaussian noise addition,
median filtering, cropping and Stir Mark Benchmark. The
results presented in this paper are quite convincing and
truly demonstrate the robustness of our watermarking method
to fundamental image processing operations.
Key words: Image Watermarking, Hadamard, Multi resolution, Non-blind detection. BibTex: @ARTICLE{P1150442004,
AUTHOR = {G.S.El-Taweel and H.M. Onsi and M.Samy and M.G. Darwish},
TITLE = {Secure and Non-Blind Watermarking Scheme for Color Images Based on DWT }, JOURNAL = {ICGST International Journal on Graphics, Vision and Image Processing}, YEAR = {2005}, MONTH = {April}, VOLUME = {05}, ISSUE = {4}, PAGES = {1--5} }
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