MIAF (Multi-Image Application Format; formerly spelled with a lowercase I: MiAF) is an image file format. It is part of the MPEG-A suite of standards, published as ISO/IEC 23000 Part 22. It is a simplified profile of HEIF. There doesn't seem to be much freely-available information about it.
This format is not related to the InstallAware .miaf format.
- ISO/IEC 23000-22:2019: MPEG-A Part 22: Multi-image application format (MIAF) (not free to download)