Contrast-to-Noise Ratio on filaments

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Filaments are grouped in sets of four differing by relative direction against the anode-cathode one. For every group the number of visible filaments is shown as well as the min, max and average CNR.

IQI CNR Filaments Group ROIs.png
IQI CNR Filaments Group ROIs legend.png

For each filament of a group, CNR is calculated using the following formula.

IQI CNR Filament ROIs.png
IQI CNR Filament ROIs legend.png


$ CNR = \frac{|\mu_D-\mu_B|}{\sigma_B} $

where:

  • $ \mu_D $: mean pixel value of the detail ROI
  • $ \mu_B $: mean pixel value of the background ROI
  • $ \sigma_B $: standard deviation of pixel values of the background ROI