Could you add resizable window with GUI?
AutoTiler for GMS2
A downloadable tool for Windows
Autotiler is simple tool that will generate tileset which you can use in Game Maker Studio 2 autotiling function.
Project is in beta state but I'm doing my best to make it fully functional.
If you found any bugs, got some questions or have feature request, feel free to write your suggestions in comment section below.
Your feedback is essential part of development in this project :)
Of course you can use generated tilesets free of charge, just mention AutoTiler in credits or something ;)
Simply unzip file and run AutoTiler.exe