Heat propagation is a new way
of looking at Gaussian filtering: variations of this concept,
for example by using the object boundaries in the image to
create inhomogeneities with respect to heat propagation, have led to a large variety of new, non-linear algorithms for image
filtering, even if convergence proofs have not always been
established. Anisotropic filtering is not a new technique, but
a new exciting way to consider a problem as ancient as image
processing.