bug fix

browser.js

@@ -0,0 +1,25 @@
+var qrDecode = require('./')
+
+var decode =
+	exports.decode = function (bom) {
+		var canvas = document.createElement("canvas")
+		var ctx = canvas.getContext('2d')
+		canvas.width = bom.width;
+		canvas.height = bom.height;
+		ctx.drawImage(bom, 0, 0, canvas.width, canvas.height);
+		var data = ctx.getImageData(0, 0, canvas.width, canvas.height);
+		return qrDecode(data)
+	}
+
+exports.decodeByUrl = function (src, cb) {
+	var img = new Image();
+	img.src = src;
+	img.onload = function () {
+		try {
+			cb(null,decode(img));
+		} catch (e) {
+			cb(e);
+		}
+	}
+	img.onerror = cb;
+}