Many applications need to segment out all small round
regions in an image. This task of finding dots can be viewed
as a region segmentation problem where the dots form one
region and the areas between dots form the other. We formulate
it as a graph cuts problem with two types of grouping
cues: short-range attraction based on feature similarity
and long-range repulsion based on feature dissimilarity.
The feature we use is a pixel-centric relational representation
that encodes local convexity: Pixels inside the dots and
outside the dots become sinks and sources of the feature
vector. Normalized cuts on both attraction and repulsion
pop out all the dots in a single binary segmentation. Our
experiments show that our method is more accurate and robust
than state-of-art segmentation algorithms on three categories
of microscopic images. It can also detect textons in
real scene images with the same set of parameters.