DyWT based copy-move forgery detection with improved detection accuracy

Copy-move forgery or region-duplication is a form of digital image forgery which copies some region(s) of an image, and pastes those onto the image itself, with an aim of obscuring important image objects. The last decade has seen rapid growth of research interest in the domain of copy-move forgery detection in digital images. Since in copy-move forgery, the duplicate regions come from the same image, this form of forgery is difficult to be detected by conventional image forgery detection techniques, which look for statistical inconsistency among different image parts. In this paper we propose a region-duplication detection technique which utilizes the Undecimated Dyadic Wavelet Transform for its operation. In the proposed approach, we divide an image into pixel sub-matrices or blocks and aim to find matches among different image blocks, so as to detect image region duplications. Similarity between blocks, with respect to features extracted using the DyWT method, is computed using the Canberra distance formula. Subsequently the detection accuracy of the proposed approach is optimized by reducing the number of false block matches. We evaluate and compare our proposed method through a comprehensive set of experiments. Our experimental results suggest that the proposed method attains considerably high detection accuracy as compared to the state-of-the-art.