  Equipping the rototranslation group $SE(2)$ with a sub-Riemannian structure
inspired by the visual cortex V1, we propose algorithms for image inpainting
and enhancement based on hypoelliptic diffusion. We innovate on previous
implementations of the methods by Citti, Sarti, and Boscain et al., by
proposing an alternative that prevents fading and is capable of producing
sharper results in a procedure that we call WaxOn-WaxOff. We also exploit the
sub-Riemannian structure to define a completely new unsharp filter using
$SE(2)$, analogous to the classical unsharp filter for 2D image processing. We
demonstrate our method on blood vessels enhancement in retinal scans.
