Geeqie can display files for which there are existing pixbuf loaders. In addition to the standard ones included with most distributions, the following loaders may also be available to you.
However, in some cases you are required to compile and install them yourself.
https://github.com/aruiz/webp-pixbuf-loader
Example installation script:
sudo apt-get install libglib2.0-dev libgdk-pixbuf2.0-dev libwebp-dev
wget https://github.com/aruiz/webp-pixbuf-loader/archive/master.zip
unzip master.zip
cd webp-pixbuf-loader-master
./waf configure
./waf build
sudo ./waf install