Run like this: >node nodecli ../panda.png -outfilename outpanda.svg numberofcolors 4 -pathomit 16 ltres 0.1 Expected result: .../outpanda.svg was saved! Please note: - You can use option names with or without - e.g. ltres 0.1 or -ltres 0.1 - Any option can be defined in any order or left out to get the defaults - option values are cast to required types e.g. with parseFloat, but no error checking here - options.pal and option presets are not supported right now PNG.js and PNGReader.js are saved on 2016-03-04 from https://github.com/arian/pngjs They have MIT license: https://github.com/arian/pngjs/blob/master/LICENSE.md