[clouddrover]

I'm not certain, but I think HEIF itself is royalty-free.

HEIF is just an image container format. The current implementation of HEIF supports JPEG, H.264, and H.265. So, yes, if you use H.264 or H.265 inside HEIF then you have all of those attendant patent licensing issues. But if you use JPEG inside HEIF or if someone implements support for VP8 or VP9 or eventually AV1 then I think you should be able to use HEIF royalty-free.

The GitHub repository is at: https://github.com/nokiatech/heif

The "License Grant" section of LICENSE.TXT sounds like it grants a royalty-free patent license to the HEIF format itself, exclusive of any codec patent licenses as you'd expect. So I think once VP9 or AV1 support is added HEIF may be a nice container format for images.