Figure 3.

Illustration of articulator boundary identification and sharpness score evaluation. (a) Airway boundary segmentation with the upper (superior-posterior) boundary (green, color online) and the lower (inferior-anterior) boundary (red, color online). (b) Gridlines of the upper (yellow) and lower boundaries (cyan) at several locations along the airway are chosen to obtain intensity profiles. (c) Intensity profile of the gridline is plotted where a sharpness metric is measured as a slope between the points of 80% and 20% of the maximum intensity values (CNR/d).