The obtained results show significant improvement in terms of quality and fidelity of extracted signal. Also, the improvements in terms of robustness by the proposed method work effectively against various common image-processing-based attacks especially against compression attacks. | Journal of Automation and Control Engineering, Vol. 1, No. 2, June 2013 A Robust Digital Watermarking using Discrete Wavelet Transform in Chrominance Channel Komwit Surachat Information and Communication Technology Programme, Faculty of Science, Prince of Songkla University, Thailand Email: Abstract—A wavelet-based digital watermarking scheme is presented in this paper. The watermark signal is embedded into HLn of LLn-1 transformed sub-band of original chrominance channel host image using coefficients scaling technique. In the extraction process, the average filter is applied to predict original dwt coefficients in HLn-1 subband. Then, the watermark logo is recovered by subtracting the coefficients predicted from the embedded coefficients, without original image needed. The obtained results show significant improvement in terms of quality and fidelity of extracted signal. Also, the improvements in terms of robustness by the proposed method work effectively against various common image-processing-based attacks especially against compression attacks. example, M. K. Samee et al. [4] presented reversible watermarking scheme for images by using CMDA based in wavelet domain. In addition, [5] and [6] proposed watermarking algorithms in frequency domain using discrete wavelet transform. They applied discrete fractional Fourier transformation DWT and Region of Interest (ROI) technique, respectively. In this paper, we present a wavelet-based digital watermarking scheme by applying some spatial domain techniques to improve the performance of extracted watermark signal. The coefficient scaling method is proposed to adjust area before embedding which will be explained more in section 2. Then, in section 3, the experimental results are shown and discussed. The conclusion is finally drawn in section 5. Index Terms—discrete wavelet transform, digital watermarking, chrominance channel, image processing based attack I. II. This proposed watermarking .
