Re: Challenge: Reverse Engineering Standard Filters

["Werner D. Streidt" <wstreidt@bigfoot.de>]

Hi Bill,

>If any of you who wish to develop code for "standard" filters that ship
with
>Photoshop, PSP, etc. want a real challenge, try to duplicate the Photoshop
>Despeckle filter.  It must be simple, because it executes extremely fast.
>It does not appear to be a variant of "blur" (there are many pixels that do
>not get changed at all), nor does it appear to be a median cut since it
>executes too fast.  I have programmed about forty variants (really!) over

Yes, it really seems like a real easy filter based on a symmetric cnv.
Possibly an automatic threshold is used... haven't found any solution yet.

255    255    255
255    190    255
255    255    255

despeckled:

251    249    251
249    246    249
251    249    251

See the symmetry?

Gotta experiment more :-)

Greetings,

Wern