共查询到19条相似文献,搜索用时 125 毫秒
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一种基于H.264/AVC的视频可逆脆弱水印算法 总被引:1,自引:0,他引:1
结合H.264压缩编码标准的特性,该文提出一种新的基于H.264/AVC的视频可逆脆弱水印算法。算法先计算当前宏块预测残差块量化的离散余弦变换(DCT)系数的哈希值生成认证码,再把认证码作为水印信息嵌入到下一个相邻宏块活性最大的4′4块的最后一个非零量化DCT系数中。在解码端,通过比较认证码和提取的水印信息进行视频数据完整性的认证。实验结果表明,该算法对视频质量和码率的影响较小,并且能对认证通过的视频数据进行还原和对认证失败的视频Ⅰ帧遭篡改区域进行有效的定位。 相似文献
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这里提出一种基于H.264/AVC低比特率的半脆弱视频水印认证方案。将从I帧能量块中提取的特征码,以修改一对AC系数间的关系,完成水印在I帧的嵌入。在P帧中,引入参考水印位对运动分量的选择机制,并通过对所选运动分量奇偶性的调制完成水印嵌入。同时在I帧中采用Lagrangian优化算法和在P帧中采用拉格朗日代价函数式方案,有效地降低了水印嵌入带来的码率提升。实验证明了该算法的有效性。 相似文献
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随着数字视频水印技术被广泛应用于视频信息的版权保护,提出一种基于H.264码流的数字视频水印方案.根据经典算法 H&G 算法的部分解码的思想,通过纹理复杂度参数和帧内预测方向在每个宏块中选择合适的4×4块,并根据DCT系数特点,选择4×4块的一个中频系数来嵌入水印.结合常用的内置式水印的嵌入方法,通过调制 DCT 系数的一个中频系数的奇偶性关系,完成水印在 I 帧的嵌入.通过对标准视频序列的测试,证明了该算法在H.264标准上的可行性. 相似文献
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针对现有视频水印算法在抗几何攻击能力方面的一些不足,提出一种基于关键帧和小波变换的盲视频水印算法.依据视频帧间差欧氏距离提取视频关键帧并分块,结合人类视觉系统特性,从关键帧不同的块中选择亮度敏感性和纹理敏感性最高的块构成三维体块,进行三维小波变换,将置乱的水印图像以不同的嵌入强度嵌入到小波系数的低频区域,利用阈值门限实现水印的盲提取.结果表明,该算法提高了水印嵌入容量,对于针对视频水印的攻击具有较好的不可见性和稳健性. 相似文献
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针对视频水印算法鲁棒性差或需过多先验信息提高鲁棒性的问题,提出利用视频帧块、KAZE特征匹配和DCT变换方法实现半盲鲁棒视频水印算法。首先,利用用户注册信息作为水印并为之产生唯一的秘钥,基于该秘钥随机产生唯一的帧块并存入数据库;然后,将帧与帧块进行KAZE特征匹配并检测出嵌入区域,进而嵌入水印;最后,将帧块与扭曲视频进行KAZE匹配修正视频各帧并提取水印。仿真试验结果显示,在半盲的前提下,本算法具有高鲁棒性、水印提取过程同步性、版权纠纷解决和非法传播追踪的优点,且具有高应用价值。 相似文献
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针对现有视频水印算法很少考虑视频帧中确定的目标区域这一问题,提出一种基于Krawtchouk矩的视频水印算法(KVW).该算法利用Krawtchouk矩的目标区域提取能力,选取视频I帧中较为重要的信息区域作为水印的嵌入域.结合Krawtchouk低阶矩对剪切攻击的鲁棒性以及视频帧间相似度较高的特点,选择I帧和相邻P帧中相对稳定的低阶Krawtchouk矩作为最优矩集合.根据随机水印比特自适应地修改集合中的矩,并对差矢量进行Krawtchouk矩重构,通过将差值图像在空域迭加到I帧嵌入水印.水印检测时,首先计算受攻击I帧的Krawtchouk矩,以最优矩集合作为密钥,用相邻P帧Krawtchouk矩替代原始I帧数据提取水印,改善算法对原始数据的依赖性.实验结果表明,KVW算法在保证获得很好图像质量的同时,能够很好地抵抗帧剪切攻击以及常规的信号处理. 相似文献
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A novel watermarking scheme for H.264/AVC video authentication 总被引:1,自引:0,他引:1
As the H.264/AVC-based video products become more and more popular, issues of copyright protection and authentication that are appropriate for this standard will be very important. In this paper, a content-based authentication watermarking scheme for H.264/AVC video is proposed. Considering the new feature of H.264/AVC, the content-based authentication code for spatial tampering is firstly generated using the reliable features extracted from video frame blocks. The authentication code, which can detect malicious manipulations but allow recompression, is embedded into the DCT coefficients in diagonal positions using a novel modulation method. Spatial tampering can be located by comparing the extracted and the original feature-based watermarks. In addition, combining ECC and interleaving coding, the frame index of each video frame is used as watermark information and embedded in the residual coefficients. Temporal tampering can be detected by the mismatch between the extracted and the observed frame index. Experimental results show that the proposed scheme can discriminate the malicious tampering from the mild signal processing. The tampered location can also be approximately determined according to the glide window and the predefined threshold. 相似文献
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In this paper, a new error concealment algorithm is proposed for the H.264 standard. The algorithm consists of two processes. The first process uses a fuzzy logic method to select the size type of lost blocks. The motion vector of a lost block is calculated from the current frame, if the motion vectors of the neighboring blocks surrounding the lost block are discontinuous. Otherwise, the size type of the lost block can be determined from the preceding frame. The second process is an error concealment algorithm via a proposed adapted multiple‐reference‐frames selection for finding the lost motion vector. The adapted multiple‐reference‐frames selection is based on the motion estimation analysis of H.264 coding so that the number of searched frames can be reduced. Therefore the most accurate mode of the lost block can be determined with much less computation time in the selection of the lost motion vector. Experimental results show that the proposed algorithm achieves from 0.5 to 4.52 dB improvement when compared to the method in VM 9.0. 相似文献
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Ji Wenping Shen Lansun 《电子科学学刊(英文版)》2007,24(3):417-420
This letter presents a novel spatial error concealment algorithm for the H.264 video coding. The error concealment algorithm is based on directional interpolation. Mojette transform is used to estimate the orientation features of the damaged blocks,and the image is interpolated in the appro-priate directions. The proposed method is compared with bilinear interpolation algorithm in the ref-erence implementation of H.264 and all directional interpolation. Experimental results prove that the proposed algorithm has better subjective and objective image reconstruction quality. 相似文献
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This letter presents a novel spatial error concealment algorithm for the H.264 video coding.The error concealment algorithm is based on directional interpolation.Mojette transform is used to estimate the orientation features of the damaged blocks,and the image is interpolated in the approDriate directions.The proposed method is compared with bilinear interpolation algorithm in the reference implementation of H.264 and all directional interpolation.Experimental results prove that the proposed algorithm has better subjective and objective image reconstruction quality. 相似文献
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基于感兴趣区域的图像认证技术 总被引:1,自引:0,他引:1
信息认证是网络安全的一个重要方面,其目的在于判断信息的完整性和可信性。该文在对以往的图像认证技术分析的基础之上,给出了一种基于感兴趣区域的图像认证算法。首先将要认证的图像分割成一定大小的基本图像块,然后根据用户给出的感兴趣区域,后续分割每一个基本图像块,并提取相应各子块的签名信息并保存分割附加码,最后将签名信息隐藏于图像子块的中频系数中。实验结果证明算法不仅对偶然攻击具有较强的鲁棒性,而且对恶意攻击具有较高的检测、定位能力,同时具有较强的自适应能力。 相似文献
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Donghyung Kim Seyoon Jeong Jin Soo Choi Gwanggil Jeon Seungjong Kim Jechang Jeong 《ETRI Journal》2008,30(4):506-515
The H.264/AVC standard has adopted new coding tools such as intra‐prediction, variable block size, motion estimation with quarter‐pixel‐accuracy, loop filter, and so on. The adoption of these tools enables an H.264/AVC‐coded bitstream to have more information than was possible with previous standards. In this paper, we propose an effective spatial error concealment method with low complexity in H.264/AVC intra‐frame. From information included in an H.264/AVC‐coded bitstream, we use prediction modes of intra‐blocks to recover a damaged block. This is because the prediction direction in each prediction mode is highly correlated to the edge direction. We first estimate the edge direction of a damaged block using the prediction modes of the intra‐blocks adjacent to a damaged block and classify the area inside the damaged block into edge and flat areas. Our method then recovers pixel values in the edge area using edge‐directed interpolation, and recovers pixel values in the flat area using weighted interpolation. Simulation results show that the proposed method yields better video quality than conventional approaches. 相似文献