The complete sourcecode of ARDECO and a compiled version for Windows are available as a plugin for our Graphite software, see the Graphite page.
Some of the most important parts of the implementation are also explained here. Implementing ARDECO requires two subtle pieces of software:
 a Delaunay triangulation. Readily available software exists (see e.g. CGAL or Jonathan Shewchuck's triangle).
 a generic rasterizer, used in different places in the Ardeco algorithm:
 in the trixels construction phase (to compute weighted barycenters in the saliency map)
 in the preintegration phase (to compute preintegrated covariance matrices over the trixels)
This source code is licensed under the GNU GPL.
types.h  Basic typedefs, useful inline functions. 
geometry.h geometry.cpp 
Point and vectors in 2d (Vec2) + operators, Polygons in 2d, SutherlandHogdman reentrant clipping. 
median.h  Computes the median of a set of (weight,value) pairs 
matrix.h  Matrix class and utilities 
image.h image.cpp  Image, memory management, RGB output. 
m_estimator.h m_estimator.cpp  M estimators (L1L2, Lp, fait, Huber, Cauchy, GemanMcClure, Welsh, Tuckey) 
bivariate.h  Bivariate functions (degree 1 to 3), and generic Mestimator fitting code 
rasterizer.h  The generic exact rasterizer 
integral.h  Instanciations of the rasterizer:

test.cpp  a simple example of using the generic rasterizer to draw antialiased polygons in an image 