Secure and robust color image dual watermarking based on LWT-DCT-SVD

Abstract

Now days advancements in multimedia technology and Information and Communication technologies (ICTs) has raised various security related concerns. Digital image watermarking is one of the new and popular techniques for the protection of multimedia content. This paper proposes an approach for digital image watermarking in which Lifting wavelet transform (LWT), Discrete Cosine Transform (DCT) and Singular Value Decomposition (SVD) have been used. The host color image is decomposed using LWT and LH3, LL3 sub bands of the third level LWT are transformed by DCT and then SVD. Security of logo (image watermark) is enhanced by using message-digest (MD5) hash algorithm and then DCT-SVD are applied to it before embedding it into LH3 sub band. The robustness of Info (Text watermark) is increased by encoding it using Hamming error correcting code. Error correcting code increases the length of watermark therefore arithmetic coding is applied that provides lossless compression. Experimental results are computed for different color image models (RGB, YIQ, YCbCr) at different gain factors, size of text watermark, different types of cover image and for attacks. The proposed method has good performance for the imperceptibility of watermarked image and robustness of watermarks. The performance of this algorithm can be improved by using various optimization techniques.