app.js

/**
 * Module dependencies.
 */

var express = require('express');
var fs = require('fs');
var app = module.exports = express.createServer();
var spawn = require('child_process').spawn
// Configuration

app.configure(function(){
  app.set('views', __dirname + '/views');
  app.set('view engine', 'jade');
  app.use(express.bodyParser());
  app.use(express.methodOverride());
  app.use(app.router);
  app.use(express.static(__dirname + '/public'));
  app.use(express.bodyParser)
});

app.configure('development', function(){
  app.use(express.errorHandler({ dumpExceptions: true, showStack: true })); 
});

app.configure('production', function(){
  app.use(express.errorHandler()); 
});

// Routes

app.get('/', function(req, res){
  res.render('index', {
    title: 'Express'
  });
});

app.post('/ocr',function(req,res){
	var img = req.body.toSend;
	var data = img.replace(/^data:image\/\w+;base64,/, "");
	var buf = new Buffer(data, 'base64');
	fs.writeFile('/tmp/logo.png', buf, 'binary', function (err) {
      if (err) throw err
        var convert = spawn('convert',['/tmp/logo.png','/tmp/logo.jpg']);
		console.log(
    })
	res.send("ok");
});
// Only listen on $ node app.js

if (!module.parent) {
  app.listen(3000);
  console.log("Express server listening on port %d", app.address().port);
}