fits top/bottom ordering

Hi, I’m writing a capturing tool and I’ve noticed that both siril and gimp (by default) will load fits files top-down.

The setting is

This actually confused me like crazy! I couldn’t work out why this was happening so I actually flip my files on write like this

                fits.write(np.flipud(self.data), compress=None)

which means I need to also flip the Bayer pattern that the sensor tells me.

The setting says “explicit keywords”… what are the keywords that I can use to say “this is really the right way up, honestly!”. Because flipping everything by default just to match with the (broken) conventions of all the other capture tools feels very unclean to me.

And for no other reason that I am very pleased to have had some (very poor quality) first light with my free raspberry pi capturing tool, here is the worst image of Andromeda you ever seen

I don’t know for Gimp, but siril load image bottom - up.

https://siril.readthedocs.io/en/stable/file-formats/FITS.html#orientation-of-fits-images

Thanks! I will add these keywords. It looks like I don’t need to flip my BAYERPAT if I use BOTTOM-UP.