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An optimized watermarking technique based on DE in DWT-SVD domain

In this paper, an optimal Discrete Wavelet Transform-Singular Value Decomposition (DWT-SVD) based image watermarking scheme using differential evolution (DE) algorithm is presented. Three-level DWT is applied to the cover image to transform it into sub-bands of different frequencies and then apply the SVD to each sub-band of third level. After applying one-level DWT to the watermark, singular values in each sub-band of the cover image are then modified by different scaling factors (SFs) to embed the watermark image. The scaling factors are optimized using the differential evolution algorithm to obtain the highest possible robustness without losing the transparency. Experimental results show that the proposed scheme maintains a satisfactory image quality and watermark can still be identified after various attacks even though the watermarked image is seriously distorted.