Rasterbator is not available for Mac but there are some alternatives that runs on macOS with similar functionality. The best Mac alternative is pdfposter, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 10 alternatives to Rasterbator and five of them are available for Mac so hopefully you can find a suitable replacement. Other interesting Mac alternatives to Rasterbator are Separation Studio (Paid), Vectoraster (Freemium), Mindcad Tiler (Paid) and A Tiling Script With Python Imaging (Free, Open Source).
This requires the installation of Python and pyPDF. Out of the gate, the script does not provide for image overlap, however there is a patch that does fix this. The patch requires replacing 5-6 lines in 3 files and adding 2-3 new ones, its very easy.
This very simple script requires the installation of Python, Python imaging and ImageMagick. Its crying out for a web front end and maybe generalization Perl and PHP versions as well as a front end. Nevertheless I tested it out and it does work.