Multiple watermarking for privacy and security of images

E-commerce has gained a wider popularity among consumers during 20^thcentury and is one of the fastest growing segments of Internet today. However, due to openness of information on internet, security becomes an important issue. One of the solutions to this problem is digitalwatermarking. Multiple watermarking is an advanced digital watermarkingwhich provides increased security and robustness as compared to singular watermarking. The existing multiple watermarking techniques lack the balance of trade off between imperceptibility, robustness and data payload.

In this paper, we propose a DWT-based segmented robust spread transform watermarking technique to balance the above mentioned parameters. The use of multiple watermarks increases the embedding capacity of watermark as compared to the singularwatermarking technique. Also, the spread transform disperse the watermark over a large number of frequencies providing robustness to volumetric as well as geometric distortions. The imperceptibility of watermark is good in terms of PSNR. Thus, the analytical and experimental results show that the proposed technique balances the trade off between imperceptibility, robustness and data payload.