ABSTRACT

Digital images are used everywhere and it is easy to manipulate and edit because of availability of various image processing and editing software. In a copy-move image forgery, a part of an image is copied and then pasted on a different location within the same image. A copy-move image forgery is done either for hiding some image object, or adding more details resulting in at least some part being cloned. In both the case, image reliability is lost. In this paper an improved algorithm based on Discrete Wavelet Transform (DWT) is used to detect such cloning forgery. In this technique at first DWT (Discrete Wavelet Transform) is applied to the input image for a reduced dimensional representation. Then the compressed image is divided into overlapping blocks. After that Lexicographic sorting is performed, and duplicated blocks are identified. Due to DWT usage, detection is first carried out on lowest level image representation. This approach increases accuracy of detection process and reduces the time needed for the detection process.