Compile:

$ make
$ sudo make install

If compilation does not work or you want to customize stuff (like disable
Xinerama support), edit config.mk first.

Note: config.mk is designed so that in most cases, you can set environment
variables instead of editing it. E.g.:
CFLAGS='-g -Os' make
export DESTDIR=/tmp/feh PREFIX=/usr; make && make install

If you are using the git version, you can run a few non-interactive tests with
"make test". This will require mdocml and perl with Test::Command.

What is feh?

https://derf.homelinux.org/p/feh/
http://linuxbrit.co.uk/feh/

Note:
For lossless rotation you will need the "jpegtran" binary supplied by the
jpeg library. In Debian, it's shipped by libjpeg-progs.