Problem opening FITS images in AIJ that use IMAGEW and IMAGEH keys

[WillB]

A PixInsight user, jt_3232 (Jaxon) began a topic on the PixInsight forum this week reporting that he could not open images in AIJ that'd been batch calibrated in PixInsight.

You can view the topic here:

https://pixinsight.com/forum/index.php?threads/fit-to-xisf-to-fit-issues.20583/

After investigation the problem appears to be caused by two ZWO ASIAIR generated FITS keywords, IMAGEW and IMAGEH, which seem to be duplicates of NAXIS1 and NAXIS2 keys.

The issue begins with the IMAGEW and IMAGEH keys that are written as integers in the FITS header by the ASIAIR app without a trailing period ".", i.e, IMAGEW 1560 - IMAGEH 1044

After calibration, PixInsight saves theses FITS files using the standard method of appending a period "." following the integer in the IMAGEW and IMAGEH fields, i.e, IMAGEW 1560. - IMAGEH 1044.

If the image is now opened in AIJ with the trailing period in the IMAGEW, IMAGEH integer fields then it is not displayed, even though the image is actually open and information can be read from the file.

This appears to be a bug in AIJ since most other FITS image readers and FITS image post processing applications are able to display the image normally, with or without the trailing period in those IMAGEW and IMAGEH FITS header fields.

You can find two sample images in this GoogleDrive folder that demonstrate the problem:

https://drive.google.com/drive/folders/1MuVIa6Ow447HLbFDNFzOoWRNifFScSTh?usp=share_link

One image is direct from the ASIAIR app that contains no trailing period "." in the integer fields for IMAGEW and IMAGEH while the second image has those trailing periods.

You can open and display the former in AIJ but the latter image opens in AIJ but does not display.

While I'm not an ASIAIR user and not personally affected by this I am posting this as a courtesy and possible bug report for AIJ developers.

Will.

[karenacollins]

Hi Will,

Thank you for the report.

Well look into being tolerate of the trailing period in the integer field. We use standardize fits i/o code, so a workaround may or may not be trivial. We'll report back here when we know more.

Karen

[karenacollins]

Hi Will,

Can you let the folks over on the pixinsight forum know that the latest AIJ daily build (5.2.0.14) is now tolerant of the trailing dot at the end of integer card values, such is those seen in the IMAGEW and IMAGEH keywords described above.

Cheers,
Karen

[WillB]

Hi Karen.

Thank you for resolving this issue so promptly and efficiently.

I have updated the topic on the PixInsight forum and also sent a P.M. to the original reporter of the problem (P.I. forum member: Jaxon, jt_3232).

Kind regards.

Will.