var execFile = require('child_process').execFile;

// Get the path for the jpegtran/cjpeg/djpeg binary
var jpegtran = require('mozjpeg-bin').jpegtran;
var cjpeg = require('mozjpeg-bin').cjpeg;
var djpeg = require('mozjpeg-bin').djpeg;

execFile(jpegtran, ['-outfile', outPath, path], function(err, stdout, stderr) {
  if (err) {
    // error
  }
  
  // do something...
});