Home About Us Laboratory Services Forensic Science Communications Back Issues January 2009 research Figure 19: Correlation of denoised c10...

Figure 19: Correlation of denoised c10 Panasonic DMCFZ4-2 images with reference patterns from all of the cameras

Figure 19: Correlation of denoised c10 Panasonic DMCFZ4-2 images with reference patterns from all of the cameras

Correlation of denoised c10 Panasonic DMCFZ4-2 images with reference patterns from all of the cameras

This figure depicts the correlation of pattern noise extracted from the denoised images from camera c10 with 11 reference patterns. The correlation values with camera c10’s reference pattern are depicted using small teal stars. Correlations, rho, are displayed on the y-axis, while the index of the image being correlated is displayed on the x-axis. The pattern is depicted as a smattering of the symbols, which range from 0.1 on the y-axis and 1 on the x-axis to .06 on the y-axis and approximately 250 on the x-axis. The correlations with camera c10’s reference pattern are centered on approximately 0.1 for the first 200 images (1 through 200 on the x-axis) because these images were also used to generate the reference pattern. For this camera, even the remaining images, 201 through 250, have similar correlation values. All of these correlation values are significantly greater than the correlation values with other camera reference patterns. Comparing with Figure 11, the correlation values for images that have undergone malicious processing by removing the noise are less than the correlation values when compared with unprocessed images. Even then the classification accuracy remains close to 100 percent. The images having the smallest correlation with camera c10’s reference pattern (such as approximately 115 on the x-axis) are again those of the night sky or similarly dark scenes. Camera c10 is a Panasonic DMCF.