noise filters

[anr]

hi all,

first, i know this is not the right forum for this post, as i am looking for more information about noise filters, avisynth or virtualdub,
i just thought this forum is as valid as others :D

well, my question is, having so many noise filters (smart smooth,temporal smooth,spatial smooth,dynamic noise,even bilinear resize,etc) and having no information about all them

- what is the best filter for removing scratches, black points, etc ??

- what is the best filter for removing "noise" that is all the movie has a grainy look, and zones with the same color has a dirty effect, but no black spots, etc...

i think these are the main sources for noise, the ones used in gknot, dont' work with the first type

thanks for your help,
anr