Digital camera identification using Colour-Decoupled photo response non-uniformity noise pattern

The last few years have seen the use of photo response non-uniformity noise (PRNU) — a unique fingerprint of imaging sensors, in various digital forensic applications such as source device identification, content integrity verification and authentication. However, the use of a colour filter array for capturing only one of the three colour components per pixel introduces colour interpolation error, while the existing methods for extracting PRNU do not take this into account and include the colour interpolation error as part of the PRNU, which leaves room for improvement. In this work we propose a new way of extracting PRNU, called Colour-Decoupled PRNU (CD-PRNU), by exploiting the difference between the physical and artificial colour components of the photos taken by digital cameras that use a colour filter array for interpolating artificial colour components from the physical ones. Experimental results presented in this work have shown the superiority of the proposed CD-PRNU to the commonly used version.