Fig. 4
From: Automated image segmentation for accelerated nanoparticle characterization

(a) cropped image; (b) binary mask of (a) after the background removal procedure in Fig. 3; (c) convex hull of (b); (d) the result of filtering (a) based on the mask in (c) and brightening the foreground by the amount in Eq. (1). Red ovals highlight the difference between the binary mask and the convex hull.