结合视频压缩编码的动态图像水印方案

本文提出了一种新的、结合视频压缩编码的动态图像水印方案。在嵌入水印时，充分考虑动态图像压缩编码的特性，对帧内编码帧(I帧)，将水印信息嵌入到DCT低额系数中；面对帧间编码帧(P、B帧)，结合动态补偿/离散余弦变换(MC/DCT)混合编码，把水印信息嵌入到运动补偿后的残差图象的直流成分中。同时，在水印嵌入时，采用扩频技术与多维水印相结合的方法，并通过相关检测的方法判断水印的存在。由于水印的检测是对视频码流直接实施的，不需要对压缩数据进行完全解码，从而大大降低了计算量，提高了视频数据水印的适用性。

Video Watermarking Combining with Hybrid Coding

A watermarking scheme combining with hybrid video coding is proposed. The intra-coded frame, which is called intra-frame, is blocked and discrete cosine transformed (DCT), watermark is embedded in the low-frequency coefficients in DCT domain. While for the inter-coded frame, the blocked motion compensation is discrete cosine transformed as in I frame, then the DC coefficient in the DCT matrix is watermarked. In this scheme, human perceptual model is considered. In the process of embedding, spread spectrum technology, which is originally used in communication, is cooperated with multidimensional watermarking technique. The watermark detection is based on the correlation and hypothesis testing and directly put on the video stream before decoding. For these reasons, computational complex can be greatly reduced to increase the usability of video watermarking.