An efficient watermarking scheme for enhanced high efficiency video coding/h.265

Abstract

In this paper, an efficient drift free watermarking scheme is proposed for enhanced high efficiency video coding standard. This standard uses multiple transforms to efficiently de-correlate the residual error of intra luma block in an I frame. Some of these transforms are not symmetric, thus cannot be used directly for embedding watermark. In this scheme, symmetric transforms are used to embed watermark into selected luma transform blocks. The relationship between the magnitudes of a pair of transform coefficients of luma transform block is utilized to embed the watermark. This pair of coefficients is selected in such a way that error drift is not propagated to neighbouring blocks during intra prediction process of the standard. Embedded watermark can be extracted by decoding only non-zero quantized transform coefficients from the compressed bit stream which makes it useful for real time applications. Experimental results justify the efficiency of the proposed scheme with respect to the existing schemes in terms of imperceptibility, bit increase rate, robustness against re-compression, noise and temporal attacks.