In today’s digital world, information is transferred in the form of document, image, audio and video. Digital images have become one of the main methods of communication. An image can define a situation or incident in a better way than words.

Images can be captured easily from non-expensive devices. Everyone can capture, store, share and alter an image easily. Digital images are used in forensic investigation, criminal investigation, medical imaging, journalism and social networking sites such as Facebook, Twitter etc. The usage of digital images and various image editing software’s has increased. Therefore it is easy to edit the image which can change all its semantics. This is called digital image forgery.

Human vision cannot discover the forgery in the re-created image. Therefore it becomes very essential and important to authenticate the originality of an image. There are two approaches to find forgery in digital images. The first approach is active approach. In this approach the authentication of image is done by some information which is pre imbedded in the image such as digital watermark and digital signatures.

The second approach called passive approach,