Illustrations for the algorithm adopted for the evaluation of the recovering capability of the U-Net model in Sutra. The panels are (a) chunk of CD map; (b): dis:gsf ​​skeleton corresponding to this chunk (Section 3.1); (c): output of the U-Net model with values lying between 0 and 1; (d) and (e): the model output is converted to threshold mask (0.1 for (d) and 0.7 for (e) panel), skeletonized and then dilated to the beam size of 12 pixels; (f): the intersection of 0.7 threshold skeleton (panel (e)) and the dis:gsf skeleton (panel (b)).