From: "Michael Herf" 
To: "Chris Livingston"; ; "Kai Krause"; "Ben Weiss"; "Todd Bogdan"
Subject: twhirled
Date: Sunday, August 09, 1998 3:33 PM

I was playing with ideas in the polar coordinate space, specifically the simple:

  pad the image
  convert rect to polar
  filter
  convert polar to rect
  crop.

But the problem is that very few of the photoshop filters "wrap", 
meaning if you want a filter to wrap through the parameter space, 
you have to run the filter on a portion of the image, offset, and 
then mask and filter on the other part, knitting them back together 
manually.  (A bit of a pain.)

Included are some images I made.  The original, then:

  twirl1: a wrapped motion blur at some random angle.  (small 
  discontinuity because I was sloppy)
  twirl2: same with offset in the y (=r) direction
  twirl3: same with offset in the x (=theta) direction -- 
  I really like this one.

So, it's making lots of sense to combine the KPT twirl (because 
we can do much cooler ones) with the polar stuff Chris wants to do.

comments?

mike