I came across a cute segmentation idea called "GrowCut" [http://graphics.cs.msu.su/en/publications/text/gc2005vk.pdf]. This paper by Vladimir Vezhnevets and Vadim Konouchine presents a very simple idea that has very nice results. I always feel that the simplest ideas are the best!
::Algorithm::
This algorithm is presented as an alternative to graph-cuts. The operation is very simple, and can be thought of with a biological metaphor: Imagine each image pixel is a "cell" of a certain type. These cells can be foreground, background, undefined, or others. As the algorithm proceeds, these cells compete to dominate the image domain. The ability of the cells to spread is related to the image pixel intensity.
The authors give some pseudocode that very concisely describes the algorithm.
<code>
//for every cell p
for all p in image
//copy previous state
labels_new = labels;
strength_new = strength;
// all neighbors q of p attack
for all q neighbors
if(attack_force*strength(q)>strength_new(p))
labels_new(p) = labels(q)
strength(p) = strength_new(q)
end if
end for
end for
</code>
See more and some experiments here:
http://www.shawnlankton.com/2008/03/growcut-segmentation-in-matlab/ |
