Tamper Detection for Shifted Double JPEG Compression

This paper presents a copy-paste block detection method based on characteristics of double JPEG compress. The JPEG compress will bring JPEG compression characteristics to the DCT coefficients, these characteristics are closely related with the quality factor. Copy-paste tamper between JPEG images will disrupt the JPEG compression characteristics of the final image. The method in this paper is designed to deal with double JPEG compression whose DCT blocks are different during the two compresses, and the experiment shows that our method can work effectively on double JPEG compression with different quality factors and is not subject to the impact of DCT blocks.