Abstract: It is difficult to detect the tampering evidence after the images with tampering operations such as splicing and synthesis are compressed. In order to achieve tamper detection of compressed images, a compressed image stitching and synthesis detection method based on camera calibration is proposed. The imaging law of compressed image is analyzed, and the spatial transformation matrix is used as the detection evidence. Based on the camera calibration parameters, the homography matrix is estimated. Based on the external parameters of the camera, the authenticity of the image is determined by rotating the spatial transformation matrix of the image, and the detection of stitched synthetic compressed image is completed. The experimental results demonstrate that this method can detect images that have been spliced, synthesized, and tampered with, with a detection accuracy of 75% .

Key words: digital forensics; , compressed images; , camera calibration; , spatial rotation matrix