Fall 2014

SGT Theory-to-Practice Seminar

Oct 21, 2014 2:00 pm – 3:00 pm 

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Ioannis Koutis (University of Puerto Rico)


Calvin Lab 116

Spectral Methods for Segmenting Neurons in EM Images

Segmenting neural structures in electron microscopic (EM) images is a crucial step in the acquisition and analysis of connectomes, i.e. maps of neural connections. Segmentation of such images is a very laborious task for humans, and it appears to be  a very difficult computational problem for which algorithms  and methods are still in their infancy. 
The talk will discuss a spectral approach based on the 'random walker'algorithm, which reduces graph segmentation with prior information to a small number of linear systems. We will show that an adaptation of the algorithm with a fair amount of 'engineering' yields a semi-automated method that finds good segmentations in only a fraction of the time required by a human. 
The problem is a natural candidate for spectral approaches: other ideas and open discussion during the talk are particularly welcome. 
(joint work with Richard Garcia)