Misc,
Digital Camera Identification
(2009)
Abstract
Forensically linking an image to a particular camera can be very useful. In a court of law, the origin of a particular photo may be crucial evidence in a case against child pornographers or industrial espionage. �ere are a number of approaches that can be taken, but most have severe issues. Metadata in the header may be lost if the image is saved into a different format and can be easily forged. Police needing to verify the authenticity of their images can use special cameras that embed fragile watermarks or store a hash of the image on a secure memory card, but in most situations the image will have been taken on a normal consumer camera. What’s needed then is a way to link the image data itself to the camera. In this essay I will be examining the method proposed by Lukáš et al. to identify cameras by their unique sensor pattern noise 5. Previous approaches include an investigation into the use of supervised learning based on a vector of numerical features extracted from the spatial and wavelet domains 4. However, this only achieved 95 % accuracy even in the best case; not good enough for most forensic work. Another research project looked at identifying cameras by pixel defects 2 but these are
