Rate Controlled Video Watermaking Based on Optimal DEM Codewords
Xiaoyan Liu, Lihong Ma, Hanqing Lu, Kang Cai · 2007
This paper addresses the rate maintenance requirement of video watermarking and proposes a differential energy watermarking (DEM) scheme. We embed a watermark bit by shifting the energy difference between horizontal edge components and the vertical ones in a quantized luminance block within a quantization cell, and spread the slight shift over coefficients for good quality and robustness. Since a slightly changed coefficient will possibly share the same segment code and a similar code-length with its un-watermarked precedent, our method could simplify the rate allocation strategy. Experimental results demonstrate that our DEM scheme performs better on visual quality impact, capacity, robustness and rate maintenance than the DEW (differential energy watermarking) scheme.