Home About Us Laboratory Services Forensic Science Communications Back Issues January 2009 research Figure 9: Correlation of noise from c5 with 11...

Figure 9: Correlation of noise from c5 with 11 reference patterns

Figure 9: Correlation of noise from c5 with 11 reference patterns

Correlation of noise from c5 with 11 reference patterns

This figure depicts the correlation of pattern noise in images from camera c5 with 11 reference patterns. The correlation values with camera c5’s reference pattern are depicted using small magenta squares. 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 .15 on the y-axis and one on the x-axis to .01 on the y-axis and approximately 310 on the x-axis. The correlations with camera c5’s reference pattern are centered on approximately 0.12 for the first 200 images (1 through 200 on the x-axis) because these images were also used to generate the reference pattern. The remaining images, 201 through 310, have slight lower correlations centered on approximately 0.05. But even these correlation values are still significantly greater than the correlation values with other camera reference patterns. The average classification accuracy is 99 percent. The images having the smallest correlation with camera c5’s reference pattern (such as approximately 245 on the x-axis) are again those of the night sky or similarly dark scenes. Camera c5 is a Nikon COOLPIX 4100.