message from michael re:challenge

[Alfredo Luis Mateus <almateus@globalsite.com.br>]

From: "Michael Johannhanwahr" <johann@icnet.de>
 To: ff@aurdev.com
 Date: Mon, 24 May 1999 23:24:45 +0200
 Subject: Re: Challenge:  Reverse Engineering Standard Filters
 
 I bet its a median cut derivate. If Adobe uses the Intel IPL (and I'm
 pretty sure they do) then it is extremely fast. I remember that Adobe
 let Intel some parts of the Photoshop source code to optimize it for
 MMX - several years ago. Intel needed some popular applications to
 demonstrate that MMX makes sense :-)
 
 Take a look at this:
 http://www.intel.com/vtune/perflibst/ipl/
 Build the samples of this library and be amazed of the speed you can
 reach.
 
 Michael.
> 
> > 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
> > the years, and never hit it yet.  Several of you have been so kind as to
> > forward suggestions in the past, but none of those withstood the test
> > either.  There must be a technique in there that we are all missing .....
> >
> > Regards, Bill
> >
> >