Robust method for detection of copy-move forgery in digital images

There is various forgeries possible on digital images such as image tampering, copy-move forgery and image compositing. Out of these, copy-move forgery is a type of image forgery, in which a part of original digital image is copied and pasted to another part in the same original image to make it, forged one. This paper describes blind image forensics approach for detecting copy-move forgery. In this technique forged image is reduced in dimension using DWT (Discrete Wavelet Transform). Then the compressed image is divided into overlapping blocks of fixed size. These blocks are sorted using lexicographic sorting and duplicated blocks are identified using Phase Correlation as similarity criterion. Detected forgery is displayed with the help of duplication map that gives count of pixels forged. This approach drastically reduces the time needed for the detection process and improves the accuracy of detection.