Dropzone - Timings to upload Images

I am using Dropzone to upload images on a form. I am overriding the 'addedFile' function to do some custom functionality to store the uploaded image locally. So, I can get these images on form submit. I am using the following code:

$dropzone.dropzone({
            url: "/file-upload",
            autoProcessQueue: false,
            uploadMultiple: true,
            parallelUploads: 6,
            maxFiles: 6,
            maxFilesize: 2.5,
            addRemoveLinks: true,

            init: function () {
                this.on("addedfile", function (file) {
                    $("#FileUploadErrorMessage").val("");
                    var uniqueId = document.getElementById("UniqueId").value;

                    setTimeout(function () { 
                        var model = {
                            FileName: uniqueId + "-" + file.name,
                            Base64Url: file.dataURL
                        };

                        var defaults = {};
                        var extendedModel = $.extend(defaults, model);

                        $.ajax({
                           // Send '**model**' variable to controller action to store file in 
                           // local directory
                        });
                    }, 3000);
                });
...

I have had to add in the 3 second timeout, around my AJAX function, as the 'file' variable (sent to the function) is undefined till dropzone have finished adding the file to the plugin. But, I need to find a better way of doing this so I don't have to set a 3 second timeout to wait for the 'file' variable because, in some case, the timescale between uploading the image to the plugin and hitting this function is more than the 3 seconds and causing the 'file' variable to be undefined when hitting the AJAX function.

Can anyone help?