[gnuastro-devel] [sr #109221] ImageWarp 'align' does not align previously warped (rotated) images

[Lee Kelvin]

URL:
  <http://savannah.gnu.org/support/?109221>

                 Summary: ImageWarp 'align' does not align previously warped
(rotated) images
                 Project: GNU Astronomy Utilities
            Submitted by: leeskelvin
            Submitted on: Tue 17 Jan 2017 03:58:01 PM GMT
                Category: ImageWarp
                Priority: 5 - Normal
                Severity: 3 - Normal
              Item Group: Output not reasonable
                  Status: None
                 Privacy: Public
             Assigned to: None
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
        Operating System: GNU/Linux

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Details:

A FITS image which has been previously rotated via ImageWarp does not align
back to N/E = Y/-X as expected.

The three files attached to this report help illustrate this issue. The input
file 'input.fits' is a standard FITS image already aligned to N on the
positive Y axis and E on the negative X axis. I initially rotate the image 45
degrees using the command:

astimgwarp --rotate=45 input.fits

This produces the output file 'input_warped.fits', attached to this report. An
attempt is then made to re-align the image back to its original alignment
using the command:

astimgwarp --align input_warped.fits

This produces the output file 'input_warped_warped.fits', also attached to
this report. As can be seen, this output has not been re-aligned back to N/E =
Y/-X. I would expect this command to re-align the image, but no operation has
been performed.

Regards, 
Lee Kelvin




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File Attachments:


-------------------------------------------------------
Date: Tue 17 Jan 2017 03:58:01 PM GMT  Name: input.fits  Size: 8kB   By:
leeskelvin

<http://savannah.gnu.org/support/download.php?file_id=39491>
-------------------------------------------------------
Date: Tue 17 Jan 2017 03:58:01 PM GMT  Name: input_warped.fits  Size: 8kB  
By: leeskelvin

<http://savannah.gnu.org/support/download.php?file_id=39492>
-------------------------------------------------------
Date: Tue 17 Jan 2017 03:58:01 PM GMT  Name: input_warped_warped.fits  Size:
8kB   By: leeskelvin

<http://savannah.gnu.org/support/download.php?file_id=39493>

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