But I can not view them with standard image viewer such XnViewMP, Geequie, GThumb, Gwenview
Gimp is ok, but Gimp is not a viewer.
In Imagemagick, there is display viewer, should function, but colours are not respected.
Is there some library to install for "standard" viewers?
In pacmac search on heic or heif gives a bunch, but which one to choose.
I see that libheif 1.6.1-1 is installed