Fig. 3

Steps showing ATFL segmentation using developed framework: a input 2D ultrasound image of ATFL region, b ROI initialised image after visual inspection by experts, c contrast enhanced image after applying adaptive histogram equalisation, d optimized image as a result of PSO, e process of contour evolution and ATFL extraction using Chan–Vese method (1–2–3) and, f ATFL extraction as binary image and hole filling (1–2)