JPEG Compression Forensics Against Resizing

摘要

In digital image forensics, identifying whether an image has been JPEG compressed is an important issue. Although the existing methods detect JPEG compression with high accuracy, their performance is degraded by resizing, which is usually used in image tampering. In this paper, a new method based on detecting block artifacts left by JPEG compression is proposed. The proposed method exposes the block artifacts via a simple spatial filter and Gaussian transformation. With some steps of feature extraction, it can be used for JPEG compression forensics. The proposed method works on any block size, which means that it can work without knowing the block size in advance. Therefore, it can be used to detect JPEG compression against resizing, which only changes the block size, but cannot destroy the block artifacts. Extensive experiments prove that the proposed method can detect JPEG compression in the presence of resizing, while it achieves a good performance as previous methods when no resizing is present.