Linux and Gimp 2.6? could be Debian 6 or a Fedora from about 2011.
Honestly do not know, I would ask the question on the ImageMagick forum https://www.imagemagick.org/discourse-server/ Users section.
Give details of your OS and the available version of IM for your distro. AFAIK you will need a version of IM that uses HDRI.
...but.. that is just my opinion, keep looking here for a sensible answer.
(edit: wouldn't be a sound file by any chance)
Honestly do not know, I would ask the question on the ImageMagick forum https://www.imagemagick.org/discourse-server/ Users section.
Give details of your OS and the available version of IM for your distro. AFAIK you will need a version of IM that uses HDRI.
...but.. that is just my opinion, keep looking here for a sensible answer.
(edit: wouldn't be a sound file by any chance)