Fig. 2.
Schematic of model-based algorithm for measuring tube diameters; (A) the selected tube section has a pixel intensity profile; (B) circles with diameters ranging from 70% to 130% of initial diameter guess are considered; (C) simulated pixel intensity profiles are calculated for each circle size; (D) a least-squares fit is performed between actual pixel intensity profiles and simulated pixel intensity profiles of different diameters; the diameter of the simulated pixel intensity profile with the minimum least-squares error when fit to the actual pixel intensity profile is the measured diameter of the selected tube section.