Robust watermarking in DWT domain using SVD and opposition and dimensional based modified firefly algorithm

The process of authenticating a digital image by embedding a watermark into it is called digital image watermarking, which protects the image from copyright infringement. This paper proposes an optimized watermarking scheme in the discrete wavelet transform (DWT) domain based on the singular value decomposition (SVD) using opposition and dimensional based modified firefly algorithm (ODFA).The host image is segmented into 8x8 non-overlapping blocks and the most suitable embedding blocks are selected for embedding. The selected blocks are then transformed into DWT domain and SVD is applied on LL1 sub-bands. Finally, the process of embedding the watermarked bits is optimized using ODFA, which applies the combination of imperceptibility and robustness as the objective function. The embedding algorithm possesses good similarity between the host and the watermarked images as well as the strong robustness against various image processing operations and attacks. Experimental results reveal that the proposed scheme has a higher degree of imperceptibility and robustness compare to related existing schemes.