一种基于HVS和DFT的栅格地图自适应数字水印算法

针对数字栅格地图数据网络分发中安全高效的需求,提出了一种基于H.264/AVC的数据隐藏算法。首先,结合H.264帧内编码特点,根据方向近似性对H.264视频4×4亮度块的9种帧内预测模式进行分组;然后,在分析当前块所采用的预测模式和数字栅格地图数据特征的基础上,建立数字栅格地图数据和预测模式之间的映射关系,根据此映射关系实现数字栅格地图数据的隐藏。实验结果表明,该方法有效降低了数据嵌入引起的视频失真强度,限制了视频位率的增加;嵌入和提取方法简单快速,保证了数字栅格地图数据网络分发的效率和安全性。

New Approach of Encrypting Embedded Data in H.264 Compressed Video

To comply with the security and high efficiency requirements for network based publishing of digital raster maps, this paper proposes a data hiding algorithm based on H.264/AVC. Firstly, by adopting the characteristics of H.264 intra frame encoding, we divided nine intra prediction modes of H.264 video (derived from 4×4 luminance blocks) into groups according to the directional approximation. Then, we established the mapping relationship between digital raster data and the prediction model, based on an analysis of the current block prediction mode and digital raster map data characteristics, and hid digital raster map data using this mapping. Experiments verified that the proposed method effectively reduces video distortion caused by embedding data and effectively limited aincrease in the video bit rate. At the same time, this embedding and extraction process was simple and fast.