node canvas load image addtext

nodecanvas.js

        var img = new Canvas.Image; // Create a new Image
				img.src = data;
				
				var canvas = new Canvas(img.width, img.height);
				var ctx = canvas.getContext('2d');
				ctx.drawImage(img, 0, 0, img.width, img.height);
				ctx.font = '22px Helvetica';
				ctx.fillText('Hello World', img.width/2, img.height/3);
				var stream = canvas.createPNGStream();*/
				
				res.writeHead(200, {'Content-Type': 'image/jpeg'});			
				stream.pipe(res);