I followed this tutorial and this is what I have come up so far: #!/usr/bin/python # -*- coding: utf-8 -*- #http://www.ibm.com/developerworks/library/os-autogimp/ from gimpfu import* def plugin_main(timg, tdrawable, maxh=540, maxw=800): currentWidth = tdrawable.width currentHeight = tdrawable.height newWidth = currentWidth newHeight = currentHeight if (maxw < newWidth): newWidth = maxw newHeight =