  Photo Response Non-Uniformity (PRNU) based camera attribution is an effective
method to determine the source camera of visual media (an image or a video). To
apply this method, images or videos need to be obtained from a camera to create
a "camera fingerprint" which then can be compared against the PRNU of the query
media whose origin is under question. The fingerprint extraction process can be
time-consuming when a large number of video frames or images have to be
denoised. This may need to be done when the individual images have been
subjected to high compression or other geometric processing such as video
stabilization. This paper investigates a simple, yet effective and efficient
technique to create a camera fingerprint when so many still images need to be
denoised. The technique utilizes Spatial Domain Averaged (SDA) frames. An
SDA-frame is the arithmetic mean of multiple still images. When it is used for
fingerprint extraction, the number of denoising operations can be significantly
decreased with little or no performance loss. Experimental results show that
the proposed method can work more than 50 times faster than conventional
methods while providing similar matching results.
