2.5-Domain Tri-Watermarking Algorithm for DCT-Based Video Protection
A 2.5-domain tri-watermarking algorithm (2.5D-TW) is presented in this paper. The proposed algorithm is the integration of dual domain bi-watermarking algorithm and visual cryptography, and the embedded tri-watermark is composed of three binary watermarks. The tri-watermark is embedded into the encoded blocks in discrete cosine transform (DCT) domain, however, the tri-watermark can be extracted from the DCT blocks and the decoded frames in spatial domain. Moreover, two types of third binary watermark of the tri-watermark are developed namely the intra-watermark and inter-watermark, those binary watermarks reveal the different robustness against various attacks. The proposed method attempts to localize the tampered areas and to detect the temporal attack.