Analysis of different footprints for JPEG compression detection

Due to the wide availability of image editing software, it becomes more easy for people to tamper with image content. This makes authentication of digital images a problem of paramount importance for forensic researchers. Therefore, a lot of methods have been proposed to detect tampering process, and many of these algorithms are based on the analysis of traces left by JPEG compression. As an important part of digital image forensics, JPEG compression detection can be used to make a rst judgment of the authenticity of images. In the light of this consideration, this thesis focuses on the analysis of JPEG compression detection, i.e., the ability of blindly understanding whether an image has been JPEG compressed or not from pixel analysis. More speci cally, in this work we focus on the analysis of two speci c stateof- the-art algorithms for JPEG compression detection: one based on pixel domain analysis; another one based on Fourier transform domain analysis. After proposing a modi cation that enhance the performance of one detector, we compare all the implemented methods showing pros and cons of these algorithms by means of a simulative campaign. Finally, in this work we also propose a graphical user interface to enable non-expert forensic investigators to use the implemented JPEG-based tools for image analysis.