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Re: poly_2d
- Subject: Re: poly_2d
- From: davidf(at)dfanning.com (David Fanning)
- Date: Wed, 4 Apr 2001 07:11:56 -0600
- Newsgroups: comp.lang.idl-pvwave
- Organization: Fanning Software Consulting
- References: <9acmh1$po$1@news.netmar.com>
- Xref: news.doit.wisc.edu comp.lang.idl-pvwave:24331
pfis@mytec.com (pfis@mytec.com) writes:
> I am using poly_2d to warp an image. I am using 3 parameters for each
> coordinate (e.g. xnew=a+bx+cy and similar for ynew). My problem is I am
> having trouble choosing 'a' such that the center of the image (actually pixel
> [64,64] of a 128x128 image) does not move. Using a=fix(-64.*(b+c-1.)) keeps
> the center stationary to about 1 pixel which is not good enough. I wrote my
> own version of the warping program which does what I want but is slower than
> poly_2d. Any help would be appreciated.
I'm wondering if ROUNDing the final result wouldn't
give you better results. (Or CEILing, FLOORing, etc.)
Cheers,
David
--
David Fanning, Ph.D.
Fanning Software Consulting
Phone: 970-221-0438 E-Mail: davidf@dfanning.com
Coyote's Guide to IDL Programming: http://www.dfanning.com/
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