HEIC and Webp pictures
Heif pictures
In LMDE 5 you have to install the package heif-gdk-pixbuf :
In a terminal:
This will install libheif1 and libde265-0 along.
sudo apt install heif-gdk-pixbuf heif-thumbnailer libheif1:amd64 gimagereader gpicview converseen
and then make Image Viewer (Afbeeldingkijker) or Eye of Gnome (Afbeeldingweergave) the default to open .HEIC images.
And converse images using converseen.
As of May 2020, programs that support HEIF via libheif1 include:
GNOME Image Viewer (Eye of GNOME - eog) is updated in Ubuntu 19.10 and later.
GPicView version 0.2.5-3
GIMP 2.10.2+
Krita version 4.2
gImageReader (in Ubuntu 22.04)
heif-thumbnailer - a thumbnailer for HEIF images that can be used by Nautilus and Nemo.
libheif-examples – provides command-line utilities: heif-convert and heif-enc.
Online Tools
Google Photos and Dropbox both reportedly support HEIF.
There are other online converters (e.g. HEICtoJPEG), but check their privacy policies before use.
Miscellaneous
Imagemagick, as of 7.0.7-22, can be compiled with the --with-libheif flag.
tifig is described as "a fast HEIF image converter aimed at thumbnailing". However, it must currently be compiled from source.
Nokia HEIF Info and Source Code. However, Apple's implementation differs somewhat.
Webp pictures
WebP GDK Pixbuf Loader library is used to read webp pictures.
UPDATE Since january 2023
sudo apt install webp-pixbuf-loader
will do the trick in Linux Mint LMDE 5
OLD information was:
Building from source is needed since debian does not have it in the repository.
Build on Debian and Linux Mint Debian Edition 4:
1. Install build dependencies:
Firstly, search for and open terminal either from start menu or from activities overview screen. When it opens, run command to install the required packages for building the library:
sudo apt install debhelper-compat meson libgdk-pixbuf2.0-dev libwebp-dev git
Type user password when it asks and hit Enter.
2. Download webp-pixbuf-loader:
To grab the source, run git command in a terminal window:
git clone https://github.com/aruiz/webp-pixbuf-loader.git
3. Build & install webp-pixbuf-loader:
Now go to the source folder in terminal window:
cd webp-pixbuf-loader
Build the library by running the commands one by one:
meson builddir -Dgdk_pixbuf_query_loaders_path=/usr/lib/x86_64-linux-gnu/gdk-pixbuf-2.0/gdk-pixbuf-query-loaders
ninja -C builddir
Finally install it via command:
sudo ninja -C builddir install
4. Clear old cached thumbnails and restart the file manager
First, fully close the file manager with this command:
nemo -q
nautilus -q
Next, delete cached failed thumbnails:
rm -r ~/.cache/thumbnails/fail
Optionally, delete all cached thumbnails:
rm -r ~/.cache/thumbnails/*
Finally, reopen the file manager. WebP images should have their thumbnails now.