This is one of my plugins for ArtEffect2/3+.

SmartMedian is a median-filter that blurs a picture without loosing sharp
edges. It can remove noise visible in large equal areas and leaving details
untouched. It is well suited to remove moirés from scanned printings without
smoothing the details out. Very useful if natural pictures are mixed with
artifical graphics/text, e.g. cover of a CD. 
Medianfilter of this type are sometimes known as despeckle filters.

There is another similar plugin available: SmartBlur

 PERMSSN    UID  GID    PACKED    SIZE  RATIO     CRC       STAMP          NAME
---------- ----------- ------- ------- ------ ---------- ------------ -------------
[generic]                11184   18652  60.0% -lh5- ada3 Jul 25  1999 plugins2/Softener.p2m
[generic]                11544   20240  57.0% -lh5- d99f Jul 25  1999 plugins2/Softener.p2n
[generic]                11182   18696  59.8% -lh5- 470a Jul 25  1999 plugins2/Softener.p4s
[generic]                 2668    6838  39.0% -lh5- bdb4 Jul 25  1999 Softener.guide
---------- ----------- ------- ------- ------ ---------- ------------ -------------
 Total         4 files   36578   64426  56.8%            Jul 25  1999