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Signal Analysis Research (SAR) Group - RNet - Ryerson University

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ing a large number of cells in Hough-Radon space shifts<br />

the peak of the accumulator to the neighbor cells and consequently<br />

results in a wrong detection of the slope in TFD.<br />

Therefore, we see in Figure 3 that DPPT-based method outperforms<br />

HRT-based algorithm in most of the attack types<br />

with a total detection of 92% compared to 87%. Also, comparing<br />

the complexity order of HRT-based and DPPT-based<br />

techniques, we conclude that the DPPT-based method is<br />

more practical for real-time applications. Figure 4, shows<br />

the complexity order and running time based on Pentium<br />

IV, CPU 2.66GHz and 512MB of RAM. DPPT-based watermark<br />

extraction is about 55 times faster than HRT-based<br />

algorithm.<br />

As we observe in Figure 3, the detection result for the<br />

BCH coding and repetition codings have almost the same<br />

detection rates, but DPPT-based method offers better or in<br />

some cases equal results when compared to REP and BCH<br />

codings. Figure 5 shows the detection results considering<br />

BER in the received message. As we see in this figure, both<br />

DPPT and BCH detect 100% watermark messages successfully<br />

up to a BER of 17%. However, the maximum BER<br />

that BCH detects a watermark correctly is 22% with 17%<br />

detection, while DPPT shows 50% detection rate at a BER<br />

of 28%. To highlight the outstanding performance of DPPT<br />

at high BERs, we calculate the watermark detection rate<br />

for BERs bigger than 17%. We see that the DPPT-based<br />

method offers 52% detection rate in higher BERs, while<br />

BCH and Repetition codings have 47% and 41% detection<br />

rates.<br />

Figure 4. Order of complexity of each coding<br />

schemes used to code the watermark message<br />

5. Conclusions<br />

In this paper, we compared FEC-based and chirp-based<br />

post processing methods in watermarking. The robustness<br />

of the proposed techniques was tested against checkmark<br />

benchmark attacks. The DPPT-based and BCH-based methods<br />

were able to compensate the BER of up to 17%. The<br />

DPPT-based post processing offered the highest detection<br />

rate of 92%, and showed the highest detection rate for BERs<br />

of higher than 17%. Also, we compared the computation<br />

complexity of the proposed methods; BCH, repetition<br />

and DPPT-based methods have almost the same complex-<br />

Proceedings of the 2006 International Conference on Intelligent<br />

Information Hiding and Multimedia <strong>Signal</strong> Processing (IIH-MSP'06)<br />

0-7695-2745-0/06 $20.00 © 2006<br />

Successful watermark estimation(%)<br />

100<br />

90<br />

80<br />

70<br />

60<br />

50<br />

40<br />

30<br />

20<br />

10<br />

HRT<br />

REP<br />

BCH<br />

DPT<br />

0<br />

0 5 10 15 20 25 30 35 40<br />

BER of the received watermark message<br />

Figure 5. Watermark detection under different<br />

bit error rates.<br />

ity, while HRT has a complexity of 55 times higher than the<br />

other methods, and this is because HRT operates on the TF<br />

plane, and calculates the accumulator value for all the cells<br />

in Hough-Radon plane.<br />

References<br />

[1] S. Erkucuk, S. Krishnan, and M. Zeytinoglu. Robust audio<br />

watermarking using a chirp based technique. IEEE Intl. Conf.<br />

on Multimedia and Expo, 2:513–516, July 2002.<br />

[2] D. Kirovski and H. Malvar. Spread-spectrum watermarking<br />

of audio signals. IEEE Transactions on <strong>Signal</strong> Processing,<br />

special issue on data hiding, 51:1020–1034, April 2003.<br />

[3] L. Le and S. Krishnan. Time-frequency signal synthesis<br />

and its application in multimedia watermark detection.<br />

EURASIP Journal on Applied <strong>Signal</strong> Processing, 2006:Article<br />

ID 86712, 14 pages, 2006.<br />

[4] J. Lee, H. Kim, and J. Lee. Information extraction method<br />

without original image using turbo code. Proc. International<br />

Conference on Image Processing, Greece, 3:880–883, October<br />

2001.<br />

[5] S. Peleg and B. Friedlander. The discrete polynomialphase<br />

transform. IEEE Transactions on <strong>Signal</strong> Processing,<br />

43:1901–1914, August 1995.<br />

[6] S. Pereira, S. Voloshynovskiy, M. Madueno, S. Marchand-<br />

Maillet, and T. Pun. Second generation benchmarking and<br />

application oriented evaluation. In Information Hiding Workshop<br />

III, Pittsburgh, PA, USA, April 2001.<br />

[7] A. Ramalingam and S. Krishnan. Robust image watermarking<br />

using a chirp detection-based technique. IEE Proceedings on<br />

Vision, Image and <strong>Signal</strong> Processing, 152:771–778, December<br />

2005.<br />

[8] R. Rangayyan and S. Krishnan. Feature identification in the<br />

time-frequency plane by using the Hough-Radon transform.<br />

IEEE Trans. on Pattern Recognition, 34:1147–1158, 2001.<br />

Authorized licensed use limited to: <strong>Ryerson</strong> <strong>University</strong> Library. Downloaded on July 7, 2009 at 11:31 from IEEE Xplore. Restrictions apply.<br />

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