libpng12-0 dependancy installation problem

[stolarczyk]

the dependency library listed in the README (libpng12-0) cannot be installed with the suggested command:

Run sudo apt-get install libpng12-0
Reading package lists...
Building dependency tree...
Reading state information...
Package libpng12-0 is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'libpng12-0' has no installation candidate

It's apparently a system version issue: https://stackoverflow.com/questions/50389939/package-libpng12-0-has-no-installation-candidate-ubuntu-18-0-4