Blind Watermarking for compressed videos in MPEG-2 Standard System Using Spread Spectrum Method

In order to protect multimedia products, digital watermarking has achieved a significant position in recent years. In this paper, two methods are proposed for embedding watermark signals in MPEG-2 standard video system. These methods could also be applicable on most of discrete cosine transform (DCT) video coding systems. In the proposed methods, watermark bits are coded using spread spectrum and Walsh codes. Afterwards, DCT is applied on the resulted vector to achieve watermark vector. The value of PSNR, influenced by watermarking, is infinite in the proposed methods. This result is due to preservation of host frame blocks DCT coefficients in the both methods. Experimental results also express high watermark capacity of proposed methods and reasonable resistance versus most of typical attacks. In the second proposed method the bit rate has a trivial increment.

کلیدواژه ها:

Watermarking ، DCT ، Spread spectrum ، Walsh codes