Full-range flags (with limited range value of "0")

Hi All,

Pixelmator and Photomator now support Export to HEIC with HDR SEI messages from imported PNG files with CICP chunks.

Both Affinity Photo, Photomator and other MacOS apps do not respect the full-range flags.

I’m working with vendors to respect the flags and scaling factor into floating point for In/Out.

Currently all of the apps are always exporting a full-range flag.

-Chris Seeger