Update README.md

README.md

@@ -11,7 +11,48 @@ In order to take full advantage of quaggaJS, the browser needs to support the `g
 
 In cases where real-time decoding is not needed, or the platform does not support `getUserMedia` QuaggaJS is also capable to decode image-files.
 
+## Installation
 
+Just clone the repository and include `quagga.min.js` in your project. The code uses [requirejs][requirejs] for dependency management.
+
+## Usage
+
+The library exposes the following API
+
+### quagga.init(config, callback)
+
+This method initializes the library for a given configuration and a function which is called when the loading-process has finished. The initialization process also requests for camera access if real-time detection is configured.
+
+### quagga.start()
+
+When the library is initialized, the `start()` method starts the video-stream and begins locating and decoding the images.
+
+### quagga.stop()
+
+If the decoder is currently running, after calling `stop()` the decoder does not process any more images.
+
+### onDetected(callback)
+
+Registeres a callback function which is triggered whenever a barcode-pattern has been located and decoded successfully. The callback function is called with the decoded data as the first parameter.
+
+### decodeSingle(config, callback)
+
+In contrast to the calls described above, this method does not rely on `getUserMedia` and operates on a single image instead. The provided callback is the same as in `onDetected` and contains the decoded data as first parameter.
+
+## Examples
+
+The following example takes an image `src` as input and prints the result on the console. The decoder is configured to detect _Code128_ barcodes and enables the locating-mechanism for more robust results.
+
+```javascript
+quagga.decodeSingle({
+  readers: [quagga.Reader.Code128Reader],
+  locate: true, // try to locate the barcode in the image
+  src: src //'data:image/jpg;base64,' + data
+}, function(result){
+  console.log(result);
+});
+```
 
 [teaser_image]: https://github.com/serratus/quaggaJS/blob/master/doc/img/quaggaJS-code128.png
 [caniuse_getusermedia]: http://caniuse.com/#feat=stream
+[requirejs]: http://requirejs.org/