DETECTION OF COPY-MOVE FORERY IN DIGITAL IMAGES USING A NOVEL FEATURE EXTRACTION APPROACH

Abstract

Digital images are easy to manipulate and edit due to availability of powerful image processing and editing software. Nowadays, it is possible to add or remove important features from an image without leaving any obvious traces of tampering. Copy –move forgery is One of the most commonly used forgery techniques in Copy-move forgery that copies a region of an image and pastes it on the other region in the same image. Several approaches have been developed so far to detect such kind of forgery. in our approach, first of all image go under pre-processing.in which image convert RGB to grey image. after that image divide in to blocks than on each blocks apply DCT(discrete cosine transform) for feature extraction. The DCT coefficients matrix is quantized and averaging is used to extract a feature set with reduce dimensionality. each feature vector are sorted by radix-sort which is less computation complex than lexicographical sort. that vectors corresponding to similar blocks come adjacent to each other. The decision of forgery can then be taken if a number of connected/similar blocks are equidistant to each other. For better result we optimize the distance by genetic optimization algorithm than match the similar blocks which are equidistant to optimized distance. The feature extraction is vital as not only does it reduce the computation complexity but choosing the correct set of features makes an approach invariant to various image manipulations such as rotation, translation, scaling, etc.