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INDI Library v1.9.8 Released (29 Sep 2022)

Bi-monthly INDI Library released with new drivers and bug fixes.

Re:Astrometry issue with fitsviewer

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Hello there. I've opened a MR about an issue I found with the fitsviewer and the ability to detect and parse wcs information.
This is here: invent.kde.org/education/kstars/-/merge_requests/150

If someone wants to review and/or speak with me about it. That would me my pleasure.

Cheers,
2 years 1 day ago #63747

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Sounds good, although I don't know what "cdfix" is. A way to unitary test this with an example fits would be nice.

-Eric
HEQ5-Pro - Atik 314E - Orion ED80T - DMK21 on Orion 50mm
DIY 3D-printed Moonlite and FWheel RGB/LPR
KStars and indiserver on two Atom 1.6GHz 1GB RAM Linux, VPN remote access
2 years 1 day ago #63758

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The explanation is quite easy. Some RGB images have a CTYPE3 = 'RGB' keyword (for Aladin compatibility[1]). It implies the existence of WCS axis 3.
The missing keywords for axis 3 (e.g. CD3_3) assume their default values. The default value for CD3_3 is 0.0, leading to a singular matrix.

The Cdfix routine tests for it and fix it. In consequence there is no problem using it. And this is also the reason why we need to extend the size of the tab.


[1]: Aladin considers a 3D FITS cube as a RGB image (Red, Blue and Green components) if the FITS keywork CTYPE3 = 'RGB ' is specified in the header. In this case any BITPIX value are supported. Without the FITS keywork CTYPE3 = 'RGB ' set, only FITS cube with 3 frames sharing the same dimension and with a BITPIX=8 will be automatically detected as RGB FITS.
Last edit: 2 years 1 day ago by lock.
2 years 1 day ago #63786

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