Easy way to create one image to different dimensions?

[denzjos]

Maybe ImageMagick can help you : https://legacy.imagemagick.org/Usage/resize/
I don't know if one can launch multiple lines in ImageMagick but in combination with a dos .bat file (one can launch a .bat file directly from explorer in windows), it is possible, see here for information : https://www.hermit.cc/it/dos/batfile.htm
Just a thought.