togif.js

#!/usr/bin/env node

if (process.argv.length < 4) {
  return console.log('usage: togif 25 path/to/files/*.jpg path/to/output.gif');
}

// node expands *.jpg

var images = process.argv.slice(2);
var delay = images.shift();
console.log('DELAY', delay);
var outfile = images.pop();

var matcher = /([0-9]+)/g;
images = images.sort(function(a, b) {
  var ai = parseInt(a.match(matcher).pop(), 10);
  var bi = parseInt(b.match(matcher).pop(), 10);
  return bi > ai ? -1 : 1;
});

images = images.concat(images.concat().reverse().slice(1));

var exec = require('child_process').exec;
var flags = ['-quality 100%'].join(' ');
var inlineFlags = ' ' + [ '-delay ' + delay, '-quality 100%', '-depth 32'].join(' ') + ' ';
var args = ['convert', flags, inlineFlags + images.join(inlineFlags), inlineFlags + '-crop 618x928+9+87! -resize 50%! ' + outfile].join(' ');

exec(args, function(err) {
  if (err) throw err;
  console.log('done! see:', outfile);
});