Study of Various Techniques Applied for Digital Image Forgery

Forensic consultant believes that no other criminal can do his activities without leaving evidence at the scene of crime. However it is hard to trace criminal proofs especially in case of digital image forgeries. Nowadays, image content alteration is a serious issue in digital image forensics. Due to numerous ways of image alteration, image splicing is a common way of image forgery. A spliced image is usually created by copying some portion or image and pasting portions of the image onto the same or another image. Much research in Image Forgery Detection has concentrated on the detection and localization of specific methods of forgery using methods like image pattern matching, comparing image histogram, patch-matching, anomaly detection, and examining residual-based local descriptors. The pixel-based picture imitation or identification intends to confirm the legitimacy of advanced pictures with no earlier learning of the first picture. There are numerous techniques for altering a picture, for example, joining or copy, move, re-examining, re-building, color enhanced etc. Copy-move falsification is a standout amongst the most prevalent altering ancient rarities in computerized pictures. This paper mainly focuses on study on various techniques used in digital image forgery.