A modified anti-forensic technique for removing detectable traces from digital images

The increasing attractiveness and trust on digital photography has given rise to new acceptability issues in the field of image forensics. There are many advantages to using digital images. Digital cameras produce immediate images, allowing the photographer to outlook the images and immediately decide whether the photographs are sufficient without the postponement of waiting for the film and prints to be processed. It does not require external developing or reproduction. Furthermore, digital images are easily stored. No conventional "original image" is prepared here like traditional camera. Therefore when forensic researchers analyze the images they don't have access to the original image to compare. Fraud by conventional photograph is relatively difficult, requiring technical expertise. Whereas significant features of digital photography is the ease and the decreased cost in altering the image. Manipulation of digital images is simpler. With some fundamental software, a digitally-recorded image can easily be edited. The most of the alterations include borrowing, cloning, removal and switching parts of a digital image. A number of techniques are available to verify the authenticity of images. But the fact is that number of image tampering is also increasing. The forensic researchers need to find new techniques to detect the tampering. For this purpose they have to find the new anti-forensic techniques and solutions for them. In this paper a new anti-forensic technique is considered, which is capable of removing the evidences of compression and filtering. It is done by adding a specially designed noise called tailored noise to the image after processing. This method can be used to cover the history of processing in addition to that it can be also used to remove the signature traces of filtering.