Forensic Image Analysis Laboratory, Incheon, Republic of Korea.
Chung-Ang University, Seoul, Republic of Korea.
Forensic Sci Int. 2019 Nov;304:109889. doi: 10.1016/j.forsciint.2019.109889. Epub 2019 Jul 29.
Due to enhanced camera performance and easy using convenience, most videos are taken and distributed by smart phones. However, smart phone video file as an evidence needs to be verified. We analyzed digital videos with basic information (resolution, shooting time, frame rate, bit depth, sample rate, and so on) and compressed patterns with unique compression algorithm adjusted to certain models. We also classified them based on their original characters. For analysis, we first estimated the virtual data quantity of a real digital video EXIF information without compression. We then analyzed the correlation between real recorded data and virtual data to calculate the original unique compression pattern. We then proposed a technical standard to identify the origin by comparing original compression ratio and remade video's compression ratio through a video editing software.
由于智能手机具有增强的摄像性能和便捷的使用方式，大多数视频都是通过智能手机拍摄和分发的。然而，智能手机视频文件作为证据需要进行验证。我们分析了具有基本信息（分辨率、拍摄时间、帧率、位深度、采样率等）和独特压缩算法的数字视频，这些算法针对特定模型进行了调整。我们还根据原始特征对它们进行了分类。在分析过程中，我们首先估计了未压缩的真实数字视频 EXIF 信息的虚拟数据量。然后，我们分析了真实记录数据与虚拟数据之间的相关性，以计算原始独特的压缩模式。最后，我们通过视频编辑软件比较原始压缩比和重制视频的压缩比，提出了一种通过比较原始压缩比和重制视频的压缩比来识别来源的技术标准。
