Abstract: With the growth of image processing technology, it is difficult to distinguish between photographic images (PIM) and photorealistic computer generated images PRCG. Watermarking was the previous technic for authentication purpose. The Demosaicing algorithm is used to detect the validity of digital images and image forgery detection.The main aim of this paper is to provide system which will help to detect the manipulation in the images.Due to technological changes, the computer generated images become more realistic. In order to distinguish between computer generated images and digital camera images we implement this approach.The whole system is controlled by administrator module.Most digital cameras employ an image sensor with a color filter array. The process of Demosaicing interposes the raw image for allocating color channels for each pixels. With proper analysis, traces of Demosaicing are revealed in the peak of an analysis signal. Theexistence of Demosaicing indicates the image is from a digital camera rather than generated by a computer.

Keyword: Demosaicing, Forgery, CFA (Color Filter Array), PIM (Photo Graphic image), PRCG (Photo Realistic Computer Generated image).