This demo efficiently computes the emd_hat between two 1-dimensional
histograms where the ground distance between the bins is thresholded L_1
emd_hat was described in the paper:
A Linear Time Histogram Metric for Improved SIFT Matching
Ofir Pele, Michael Werman
ECCV 2008
The efficient algorithm is described in the paper:
Fast and Robust Earth Mover's Distances
Ofir Pele, Michael Werman
ICCV 2009