Denoise Frei0r plugins


For now, I have only ported the Daniel Moreno's hqdn3d filter from
Mplayer.

I have also tried Mplayer's "ow" (overcomplete wavelet) denoiser, but
despite being only 2D, it is EXTREMELY slow (like <1fps...), so I 
decided not to include it for now.

In the future I would like to try at least a thresholded 3D median,
and maybe port something like fftdenoise3d from Avisynth. That
is a pretty big chunk of code, and originally written for another
operating system, so much more work, and it depends when I'll have
the spare time for that.

Or maybe some other "smart" denoiser, suggestions welcome.



HQDN3D

This is a three dimensional nonlinear IIR filter. Does a pretty god
job at moderate noise levels. For stronger denoising, it becomes a bit
asymmetric, which is a consequence of its IIR form.