论文标题
使用基于块的加权从编码视频中估算的PRNU估算
PRNU Estimation from Encoded Videos Using Block-Based Weighting
论文作者
论文摘要
从视频中估算成像传感器的照片反应不均值（PRNU）是一项艰巨的任务，这是由于相机成像管道中的多个处理步骤所产生的并发症。在这些步骤中，视频编码是PRNU估计的最具破坏性之一，因为其损失性质。由于视频始终以压缩格式存储，因此应对编码的破坏性影响的能力对于可靠的归因至关重要。在这项工作中，通过关注广泛使用的视频编码标准的基于块的操作，我们提出了一种改进的PRNU估计方法，以利用这种行为。为此，提出并比较了几种利用块级参数的PRNU加权方案，例如编码块类型，量化强度和速率延伸值。我们的结果表明，与为照片开发的基本估计方法相比，在低至中型编码比特率时，块的编码速率可以作为PRNU强度的更好估计器，在低至中型编码比特率下的匹配统计量几乎提高了三倍。
Estimating the photo-response non-uniformity (PRNU) of an imaging sensor from videos is a challenging task due to complications created by several processing steps in the camera imaging pipeline. Among these steps, video coding is one of the most disruptive to PRNU estimation because of its lossy nature. Since videos are always stored in a compressed format, the ability to cope with the disruptive effects of encoding is central to reliable attribution. In this work, by focusing on the block-based operation of widely used video coding standards, we present an improved approach to PRNU estimation that exploits this behavior. To this purpose, several PRNU weighting schemes that utilize block-level parameters, such as encoding block type, quantization strength, and rate-distortion value, are proposed and compared. Our results show that the use of the coding rate of a block serves as a better estimator for the strength of PRNU with almost three times improvement in the matching statistic at low to medium coding bitrates as compared to the basic estimation method developed for photos.
