Two examples of inaccurate nucleus segmentation due to erroneous initial segmentation of the (a) nucleus and (b) cytoplasm. In each sub-figure, from left to right are original image, initial segmentation, ground truth segmentation, ground truth nucleus, and our segmentation, respectively. The green point labels the initial detected nucleus center. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of the article.)