Abstract: Inconsistency of blocking artifacts is introduced when image regions with different JPEG quality factors or grids are spliced for forgery. A novel image forgery detection method was proposed to automatically locate the tampered regions. The compression noise was firstly extracted from the images using a wavelet based denoising filter. The proposed method measured the JPEG blocking artifact using the compression noise to improve the SNR. Then an appropriate threshold was found using an iterative method to separate tampered regions in the histogram of blockiness metrics.Experimental results were presented to demonstrate the effectively and reliability of our method.

Key words: Image forensics,Image forgery,Blocking artifacts,JPEG