Below is a C++ implementation of the fast distance
transform algorithm described in the paper:
Distance Transforms of Sampled Functions.
Pedro F. Felzenszwalb and Daniel P. Huttenlocher.
Cornell Computing and Information Science TR2004-1963. ps.gzpdf
The source code is available as a tgz file dt.tgz,
or zip dt.zip (updated on 12/28/06).
