Help req: IDL to Python, numarray-Numeric

[Ray Schumacher]

Hi all,

I'm trying to port Hongjie Xie's IDL/ENVI Implementation of the FFT Based
Algorithm for Automatic Image Registration
ftp://ftp.iamg.org/VOL29/v29-08-10.zip
http://www.nmt.edu/~hjxie/xie-paper.pdf
http://www.iamg.org/CGEditor/cg2003.htm
to Python/numarray/Numeric and running into some subtle problems.

I don't have IDL, so I could only read the PDF docs.

For instance, the IDL ROT() requires some additional steps to emulate, and
the MAX(array, position) as well.
And, I'm not at all familiar with the correspondence of the FFT
libraries... even the simple shift-only routine
http://rjs.org/astro/1004x/Python/register/shift_idl.py
produces different (incorrect) x shift values than the IDL.

My current code
http://rjs.org/astro/1004x/Python/register/
conforms to Xie's flow as much as possible for now, but should and will be
re-factored when functional. His LogPolar function, to convert rectangular
coordinate arrays to polar, is particularly slow.

If anyone has some insight as to possible, critical differences, please let
me know!

Thank you,
Ray Schumacher
user:ray at the domain rjs daaat oh-arr-gee

 

[Robert Kern]

Hi all,

I'm trying to port Hongjie Xie's IDL/ENVI Implementation of the FFT Based
Algorithm for Automatic Image Registration
ftp://ftp.iamg.org/VOL29/v29-08-10.zip
http://www.nmt.edu/~hjxie/xie-paper.pdf
http://www.iamg.org/CGEditor/cg2003.htm
to Python/numarray/Numeric and running into some subtle problems.

I don't have IDL, so I could only read the PDF docs.

I'll try to find some time to look at what you have, but in the
meantime, did you know that you can download evaluation copies of IDL
and ENVI?

http://www.rsinc.com/download/chooseplatform.asp?urlProductCode=20

You're limited to seven minute sessions, but it ought to be good enough
to try pieces of code out.

--
Robert Kern
(e-mail address removed)

"In the fields of hell where the grass grows high
Are the graves of dreams allowed to die."
-- Richard Harter

 

[RJS]

Hi Robert,

I'll try to find some time to look at what you have, but in the
meantime, did you know that you can download evaluation copies of IDL
and ENVI?

http://www.rsinc.com/download/chooseplatform.asp?urlProductCode=20

You're limited to seven minute sessions, but it ought to be good
enough to try pieces of code out.

Thanks!
No I didn't know there was a trial, I'll check it out again. The paper's
author isn't to interested in Python, but I'm trying to get the STSI
interested as a numarray add-on, as almost the entire process should be
do-able with numarray or Numeric.
..
I'm in La Jolla also, if you're interested in this yourself. I ride
through Scripps almost daily.

Ray
user:ray at the domain rjs daaat oh-arr-gee