%0 Journal Article
%T An Overview on Image Forensics
%A Alessandro Piva
%J ISRN Signal Processing
%D 2013
%R 10.1155/2013/496701
%X The aim of this survey is to provide a comprehensive overview of the state of the art in the area of image forensics. These techniques have been designed to identify the source of a digital image or to determine whether the content is authentic or modified, without the knowledge of any prior information about the image under analysis (and thus are defined as passive). All these tools work by detecting the presence, the absence, or the incongruence of some traces intrinsically tied to the digital image by the acquisition device and by any other operation after its creation. The paper has been organized by classifying the tools according to the position in the history of the digital image in which the relative footprint is left: acquisition-based methods, coding-based methods, and editing-based schemes. 1. Introduction Images, unlike text, represent an effective and natural communication media for humans, due to their immediacy and the easy way to understand the image content. Historically and traditionally, there has been confidence in the integrity of visual data, such that a picture printed in a newspaper is commonly accepted as a certification of the truthfulness of the news, or video surveillance recordings are proposed as probationary material in front of a court of law. With the rapid diffusion of inexpensive and easy to use devices that enable the acquisition of visual data, almost everybody has today the possibility of recording, storing, and sharing a large amount of digital images. At the same time, the large availability of image editing software tools makes extremely simple to alter the content of the images, or to create new ones, so that the possibility of tampering and counterfeiting visual content is no more restricted to experts. Finally, current software allows to create photorealistic computer graphics that viewers can find indistinguishable from photographic images [1, 2] or also generate hybrid generated visual content. In summary, today a visual digital object might go during its lifetime, from its acquisition to its fruition, through several processing stages, aimed at enhancing the quality, creating new content by mixing pre existing material, or even tampering with the content. As a consequence of all previous facts, doctored images are appearing with a growing frequency in different application fields, and thus today¡¯s digital technology has begun to erode the trust on visual content, so that apparently ¡°seeing is no longer believing¡± [3¨C5]. All these issues will get worse as processing tools become more and more sophisticated.
%U http://www.hindawi.com/journals/isrn.signal.processing/2013/496701/