Camera Fingerprint Extraction via Spatial Domain Averaged Frames
This incremental improvement addresses efficiency for forensic analysts handling large datasets of images or videos in camera source identification.
The paper tackles the time-consuming process of camera fingerprint extraction for PRNU-based attribution by proposing Spatial Domain Averaged frames, which reduce denoising operations by averaging multiple images, achieving over 50 times faster processing with similar matching performance.
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.