Temporal forensic analysis of digital Camera sensor imperfections for picture dating

该研究计划旨在调查相机传感器缺陷的时间变化，以便为任何给定的数码相机建立一个理论模型，使分析师能够估计数字照片的获取日期。这将推进法医学领域，有可能应用于需要为法庭目的提取证据信息的备受瞩目的案件。在这个项目中，假设分析师有相机设备或由同一相机拍摄的一组可信照片，并且其获取时间是已知的。然后，目标是确定一张或多张据称从同一来源获得的图像的日期，这些图像的获取时间未知。该方法的创新之处在于：(I)用于时间分析的有效估计传感器模式噪声的新技术(Ii)对三种类型的像素进行分类和时间分析，即正常像素、异常但尚未损坏的像素和缺陷像素。(3)使用机器学习技术对相机传感器缺陷的时间行为进行建模。

The research proposal aims to investigate the temporal variations of camera sensor imperfections in order to establish, for any given digital camera, a theoretical model that allows the analyst to estimate the acquisition date of digital pictures. This will advance the field of forensic science, with the potential for applications in high profile cases that require the extraction of evidential information for courtroom purposes. In this project, the analyst is assumed to have the camera device or a set of trusted pictures taken by the same camera and whose acquisition time is known. The goal is then to date one or more images supposedly obtained from the same source and whose acquisition time is unknown. This application will obviously help forensic investigators analyse incidents and link different events.The novelty of the proposed approach lies in (i) New techniques for efficiently estimating the sensor pattern noise for the purpose of temporal analysis (ii) Classification and temporal analysis of three types of pixels, namely, normal pixels, abnormal but not yet defective pixels, and defective pixels. (iii) Use of machine learning techniques to model the temporal behaviour of camera sensor imperfections.