Example below shows how to open an existing image on the page and save it to the server when "save" button in pixie interface is clicked.

Important:
Snippet below will only send base64 encoded image data to http://your-site-url.com url, your server will need to handle actual saving of the data on filesystem.
<img id="open-me" src="assets/images/sample.jpg">

<script>
    var pixie = new Pixie({
        onLoad: function() {
            pixie.openMainImage(document.querySelector('#open-me'));
        },
        onSave: function(data, name) {
            pixie.http().post('http://your-site-url.com', {name: name, data: data}).subscribe(function(response) {
                console.log(response);
            });
        },
    });
</script>
Note:
Pixie will send JSON requests to the server. This sometimes might require you to access request data differently the form post data. For example, on basic PHP, you would do it like so:
# Get JSON as a string
$json_str = file_get_contents('php://input');

# Get as an array
$json_obj = json_decode($json_str, true);