bug#51381: HEIF image format support

[Stefan Kangas]

Severity: wishlist

Apple seems to have moved over to use the HEIF image format.  It seems
like Canon is also trying to push this for their cameras, and it is
being presented as a "JPEG replacement".

Whatever we think of that, this means that many unsuspecting Emacs will
soon be faced with such images.

For example, I stumbled upon this comment from one user:

    "I have used image-dired from time to time, but less so now since
    Apple's default image type is .heic. I can't open these images in
    the emacs-mac (Mitsuharo's version).

    "Is there any work ongoing to natively open .heic in Emacs?"

    https://www.reddit.com/r/emacs/comments/nzxms5/comment/h1vbepq/

GIMP, imagemagick, krita, nomacs, etc. have added HEIC support using the
LGPLv3 licensed library libheif.[1]

See more about where it is supported here:

https://en.wikipedia.org/wiki/High_Efficiency_Image_File_Format#Support

Should Emacs have built-in support for the HEIC image format?  Would it
be welcome if someone wrote up a patch for it?

Footnotes:
[1]  https://github.com/strukturag/libheif