Copy- Paste Forgery Detection Using Statistical Fingerprints

A digital image is a numeric representation of a two-dimensional image. Depending on whether the image resolution is fixed, it may be of vector or raster type. Without qualifications, the term "digital image" usually refers to raster images also called bitmap images. When we see a picture on our monitor or use our digital camera (or scanner), the image we are viewing or dealing with is not continuous like a pencil drawing – it is made up of many small elements next to each other. When we have enough elements, we get the illusion of a picture or image. Early digital images (before color) appeared in black and white. The tiny elements that comprised digital images were either black or white. These two ‘colors’ corresponded to 1 and 0 (called BITS or BI-nary digits). Digits 1 and 0 are used in the binary (base 2) system. Thus, a map (pattern) made up of these 1’s and 0’s was referred to as a bit-map. All digital images are a rectangle or square. Today, the elements are called pixels. Digital forensics (sometimes known as digital forensic science) is a branch of forensic science encompassing the recovery and investigation of material found in digital devices. Digital image forensics aims at validating the authenticity of images by recovering information about their history. Two main problems are addressed: the identification of the imaging device that captured the image, and the detection of traces of forgeries. Forensics means the use of science and technology in the investigation and establishment of facts. So the photographs or other pictures can be transmitted to and reconverted into pictures by another computer. With the widespread availability of image editing software, digital images have been becoming easy to manipulate and edit even for non-professional users. Keywords-Digital image Forensics, Correlation Based Measures.PSNR, RMSE.