A new approach for detecting Copy-Move forgery in digital images

Copy-move attack is a special type of image forgery, in which a part of a digital image is copied and pasted to another part in the same image in order to cover an important image feature. This paper describes a new and blind forensics approach for detecting copy-move forgery. Our technique works by first applying DWT (discrete wavelet transform) to the input image to yield a reduced dimension representation. Then the phase correlation is computed to estimate the spatial offset between the copied region and the pasted region. The copy-move regions can be easily located by the idea of pixel-matching, which is shifting the input image according to the spatial offset and calculating the difference between the image and its shifted version. The experimental results show that our method is more efficient than other existing algorithms, and is reasonably robust to various types of copy-move post processing.