Evaluation of Image Forgery Detection Techniques using DCT, DWT and QCD

Digital photographs are easily manipulated due to advancements in image processing tools, making it difficult to verify their authenticity. Copy and move type forgery, where a part of an image is duplicated and pasted in another location, reduces the image's dependability. A hybrid algorithm based on DWT and DCT is proposed to detect such cloned forgeries. In the proposed work we have used and hybrid algorithm which is based on DWT and DCT that is used to detect such kind of cloned forgery. The suggested technique reduces the dimensional representation of the image by first compressing it using DCT and then DWT. The compressed image above is then separated into overlapping chunks. After that, duplicate blocks are identified using a lexicographic technique. Compared to individual DCT or DWT, this method improves accuracy at the expense of a small increase in detection time. It decomposes the image through DCT and Hu moments features are extracted vector from a circle block for detection and localization of forged areas. The proposed technique dose precise detection and localization of all kinds of copy & move areas also if some kind of post processing operation has been carried out with image.