随着可伸缩视频编码SVC(Scalable Video Coding)的普及,针对可伸缩视频的安全问题也越来越受到重视。目前大部分加密方案都是针对H.264/AVC编码标准来设计的。分析SVC新采用的技术,并率先提出了一种针对其特点的新的分层加密方案。该方案选取不同以往的视频关键信息,如层间预测运动向量,质量可分级关键帧等作为加密对象,根据所选信息的类型,结合用户所需求的安全等级,进行算法设计。试验结果表明该方案具有加密效果好、密钥量较低、实时性高等优点,并可以适应不同安全性需求的应用场合。
A selective encryption scheme for region of interest(ROI) of H.264 video is proposed to protect the personal privacy in a video. The most important part of video can be protected with less cost and operation by only encrypting the content of ROIs. Human face regions are selected as ROI and detected by using Gaussian skin color model. Independent ROI encoding is realized with the mechanism of flexible macro-block ordering(FMO). Frames are divided into grid-like slice-groups which can be combined flexibly to form a required ROI.Both luminance component and chrominance component of the macro-blocks in ROI are modified to achieve good encryption quality and location accuracy. In the process of decryption, the encrypted area is located automatically.There is no need to transmit additional position information of ROIs to the end of decryption. The encrypted video is decrypted correctly with the secret key. JM18.4 software is employed to perform the simulation experiment.Experimental results show the accuracy and effectiveness of our scheme to encrypt and decrypt the ROIs in H.264 video.
