createVoronoi(centr​oids,imageFilename)

Given a list of centroids, it computes the 2D/3D voronoi diagram and extracts each Voronoi cell from the original image.
The voronoi diagram is calculated based on the Euclidean distance in 3D space.
centroid = [x1 y1 z1]
voxel = [x2 y2 z2]
for each voxel
Euclidean distance = sqrt((x2-x1)^2+(y2-y1)^2+(z2-z1)^2)
end
% Input:
% centroids - N x 3 matrix
% imageFilename - filename of image stack