First install all these prerequisites for compiling:
sudo apt install g++ autoconf libfontconfig1-dev pkg-config libjpeg-dev libopenjpeg-dev gnome-common libglib2.0-dev gtk-doc-tools libyelp-dev yelp-tools gobject-introspection libsecret-1-dev libnautilus-extension-dev
First download the encoding files (no need to compile these) to the current working directory
wget https://poppler.freedesktop.org/poppler-data-0.4.7.tar.gz
Extract (it does untar cleanly):
tar -xf poppler-data-0.4.7.tar.gz
Enter the directory
cd poppler-data-0.4.7
And magically send the files to the right locations in /usr/share with:
sudo make install
Now go back up one level
cd ..
Download & extract the main package:
wget https://poppler.freedesktop.org/poppler-0.48.0.tar.xz
tar -xf poppler-0.48.0.tar.xz
cd poppler-0.48.0
Now run the configure file like this:
./configure
Here you will get errors if I missed anything from my list of dependencies above. The errors might be illuminating eg 'thing-you-need not found' in which case you can try sudo apt install thing-you-need and try again. If that doesn't work, try searching online for the error message.
If it exits without errors you can run:
make
Which will take a while. When it's done, you can use
sudo make install
If you use sudo make install you can still uninstall at any time by entering the source directory (so keep it!) and typing sudo make uninstall
Symlink the binaries to the /usr/bin directory
sudo ln -s /usr/local/bin/pdftotext /usr/bin/pdftotext
sudo ln -s /usr/local/bin/pdftoppm /usr/bin/pdftoppm
sudo ln -s /usr/local/lib/libpoppler.so.64 /usr/lib/libpoppler.so.64
libopenjp2-7-dev in bionic