How to do composite with gm node.js?

Question

How to do 'gm composite -gravity center change_image_url base_image_url' with GM Node.js?

How to call gm().command() & gm().in() or gm().out() to achieve the above?

Answer 1

After struggling for an hour, here is my solution for your question:

gm composite -gravity center change_image_url base_image_url

gm()
.command("composite") 
.in("-gravity", "center")
.in(change_image_url)
.in(base_image_url)
.write( output_file, function (err) {
  if (!err) 
    console.log(' hooray! ');
  else
    console.log(err);
});

Good luck! Hope it will be helpful to others as well :)