[Gimp-user] how to correct optical distortions of wide-angle lenses?

2002-01-24 Thread Peter Buckenleib 

Hi folks,

is there a way to correct optical distortions of wide-angle lenses ( most 
annoing within architectural pics ) using gimp ? 

I'm dreaming of something like stetching the upper side, interpolate all the 
pixel-lines down to the bottom-line (which remains unstretched) and then 
cutting away the resulting triangles on the left and right side to restore 
the original size of the scan.

I didn't find a hint how to do that till now. Perhaps somebody knows about 
some script-fu module(s) or docs i am missing or didn't find yet.

Thanks in advance


Peter



 
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Re: [Gimp-user] how to correct optical distortions of wide-angle lenses?

2002-01-24 Thread Peter Buckenleib 

Am Donnerstag, 24. Januar 2002 21:55 schrieb Rich Shepard:
 On Thu, 24 Jan 2002, Peter Buckenleib wrote:
  is there a way to correct optical distortions of wide-angle lenses
  ( most annoing within architectural pics ) using gimp ?

 Peter,

   That's an interesting idea. Have you thought of doing the
 correction as you take the photograph? If you keep the film plane
 parallel to the front of the building you won't have the distortion.
 Without a full, tilt-and-swing bellows arangement on your camera, you
 can do it by choosing the proper lens and shooting position. Of
 course, sometimes you just cannot get to the right position. :-)

   Good luck!

 Rich

 Dr. Richard B. Shepard, President

Applied Ecosystem Services, Inc. (TM)
 2404 SW 22nd Street | Troutdale, OR 97060-1247 | U.S.A.
  + 1 503-667-4517 (voice) | + 1 503-667-8863 (fax) |
 [EMAIL PROTECTED] http://www.appl-ecosys.com

Hello Dr. Shepard,

i think youre talking about the Scheimpflug-method. 

But i do not own a  camera that is capable of that (SINAR,Rollei, etc). 
These would be too heavy, complicated and time-consuming to be used at 
holliday-trips. I'm using a Minolta 800si and a SIGMA-Zoom (28-200).  

As long as i had time enough to convert my bathroom into a darkroom for 
days, i used a method like this to correct that distortion when 
exposing the prints. 

So i thought this could be done mathematically on the pixels in RAM. 
There are more than needed for a close to chemical-print since i got 
a Canon FS4000 filmscanner.


thanks for your  Mail

Peter


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Peter Buckenleib
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91056 Erlangen

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