GNU Astronomy Utilities - Bugs: bug #50073, ImageWarp 'rotate' does not...
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bug #50073: ImageWarp 'rotate' does not correctly propagate WCS pixel scale information into header
Submitter: | Lee Kelvin <leeskelvin> | ||
Submitted: | Wed 18 Jan 2017 01:20:44 AM UTC | ||
Category: | All Gnuastro | Severity: | 4 - Important |
Item Group: | Output not reasonable | Status: | Fixed |
Privacy: | Public | Assigned to: | makhlaghi |
Open/Closed: | Closed |
Jump to the original submission
Fri 20 Jan 2017 06:14:00 PM UTC, comment #7: |
Lee Kelvin <leeskelvin> |
Fri 20 Jan 2017 04:59:30 PM UTC, comment #6: Sorry for these messages, but this final confirmation idea came to me after posting the previous comment.
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Mohammad Akhlaghi <makhlaghi>![]() ![]() |
Fri 20 Jan 2017 04:43:58 PM UTC, comment #5: Sorry, I just remembered you had uploaded your version of `input_rotated.fits'. So I downloaded it and tried it out. Indeed the `WCSLIB' keyword wasn't present. But more importantly/strangely after "blink"ing (sorry, in the previous comment, I mistakenly said "flip"!) I also noticed a shift!
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Mohammad Akhlaghi <makhlaghi>![]() ![]() |
Fri 20 Jan 2017 04:28:02 PM UTC, comment #4: Thanks for the check.
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Mohammad Akhlaghi <makhlaghi>![]() ![]() |
Fri 20 Jan 2017 03:37:46 PM UTC, comment #3: Hello, and thank you for quickly addressing this issue. I can confirm that using the latest build of GNUAstro largely fixes this issue.
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Lee Kelvin <leeskelvin> |
Wed 18 Jan 2017 02:06:04 AM UTC, comment #2: Thanks again for this great description and wonderful suggestion. The issue has been fixed and pushed to the main repository.
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Mohammad Akhlaghi <makhlaghi>![]() ![]() |
Wed 18 Jan 2017 01:20:44 AM UTC, comment #1: This item has been reassigned from the project GNU Astronomy Utilities support tracker to your tracker. |
Mohammad Akhlaghi <makhlaghi>![]() ![]() |
Wed 18 Jan 2017 01:20:44 AM UTC, original submission:
On applying an image rotation using ImageWarp, the World Coordinate System (WCS) pixel scale information is only partially transferred to the output image.
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Lee Kelvin <leeskelvin> |
Depends on the following items: None found
Items that depend on this one: None found
There are 0 votes so far. Votes easily highlight which items people would like to see resolved in priority, independently of the priority of the item set by tracker managers.
Follow 9 latest changes.
Date | Changed by | Updated Field | Previous Value | => | Replaced by |
---|---|---|---|---|---|
2017-01-20 | makhlaghi | Attached File | - | ![]() |
Added input_rotated_mohammad.fits, #39520 |
2017-01-20 | leeskelvin | Attached File | - | ![]() |
Added input_rotated.fits, #39518 |
2017-01-18 | makhlaghi | Category | None | ![]() |
All Gnuastro |
Severity | 3 - Normal | ![]() |
4 - Important | ||
Item Group | None | ![]() |
Output not reasonable | ||
Status | None | ![]() |
Fixed | ||
Assigned to | None | ![]() |
makhlaghi | ||
Open/Closed | Open | ![]() |
Closed | ||
2017-01-18 | makhlaghi | Reassign item | GNU Astronomy Utilities, sr #109222 | ![]() |
GNU Astronomy Utilities, bug #50073 |
Thank you for all this extra information! What bizarre behaviour! How curious that MJD-OBS should interfere with the plotting of images in DS9...? I do not understand why this should be the case.
Firstly, I followed your suggestion and upgraded my version of DS9. I am now running DS9 version 7.5. This did make a difference (bringing the before and after images into closer agreement), but did not completely fix the issue.
On your suggestion, I upgraded my WCSLIB to version 5.15. I have recompiled GNU Astro and I can now confirm that the CDELTn header keywords print all significant figures and does also print MJD-OBS into the header.
As an aside, task #14315 may help with issues such as this in the future, by propagating all FITS header keywords into any resultant output files.
I attempted to blink between the images and, once more, found a small offset. The offset now is exceptionally small (single-pixel level), and I would not have noticed it had we not started this bug hunt with a much larger offset.
I took a close look at the header to see if anything else was going on. I found a few things:
However, on a whim, I tried one more thing... I used DS9 to blink between exactly the same input image! Lo and behold, I found an offset! The same single-pixel level offset I mentioned above. So, I can conclude that the initial bug has now been fixed by upgrading to the latest version of WCSLIB and DS9, and this continuing mis-match must be a DS9 issue.
Thank you for your help with this bug, much appreciated.
Best,
Lee Kelvin