Table 5 Image quality related attributes tested as explanatory confounding factors in the statistical modelling applied to the quantitative particle data. Lo = lower threshold as calculated by the particle hysteresis detection algorithm. a chosen as suitable for modelling of influences on particle count loss, b chosen as suitable for modelling of influences on particle area change, c used for calculation of the background distortion index (BDI)
Name | Description | Mathematical Expression |
|---|---|---|
pre_histBGpeak | pre-treatment image background brightness | grey value at the local histogram maximum between but not including 0 and Lo |
pre_histFGpeak | pre-treatment image foreground brightness | grey value at the local histogram maximum between but not including Lo and 255 |
post_histBGpeak | post-treatment image background brightness | grey value at the local histogram maximum between but not including 0 and Lo |
post_histFGpeak | post-treatment image foreground brightness | grey value at the local histogram maximum between but not including Lo and 255 |
pre_histDelta a | contrast spreading between the image background and foreground prior to treatment | \( \mathsf{pre}\_\mathsf{histFGpeak}-\mathsf{pre}\_\mathsf{histBGpeak} \) |
histBGpeakSum c | combined background brightnesses | \( \mathsf{pre}\_\mathsf{histBGpeak}+\mathsf{post}\_\mathsf{histBGpeak} \) |
histBGpeakDist b, c | mismatch between pre- and post-treatment background brightness | \( \mid \mathsf{pre}\_\mathsf{histBGpeak}-\mathsf{post}\_\mathsf{histBGpeak}\mid \) |