Send a url to a database

Image of the table images: link

Hi, I was doing a drawing game made with canvas and I have a "Upload" button with which I would like to upload the url of the image to the bd.

I have a function with which I can create a canvas url:

function pujar() {
var canvas = document.getElementById("canvas");

canvas.toBlob(function(blob) {
    var novaImatge = document.createElement("img"),
    url = URL.createObjectURL(blob);
    alert(url);

    novaImatge.onload = function() {
        URL.revokeObjectURL(url);
    };

    novaImatge.src = url;

    $('#pujar').remove();
});

My question comes here: Is there a way to call a php file inside the function to insert the url in the table? Right now my php file looks like this:

insert.php

include 'templates/database.inc.php';

//Per a afegir
include_once 'templates/magicquotes.inc.php';

try {
    $sql = 'INSERT INTO imatges SET url = :"contingut"';
    $s   = $pdo->prepare($sql);
    $s->execute();
}
catch (PDOException $e) {
    $error = 'No se ha pogut insertar la imatge: ' . $e->getMessage();
    include 'templates/error.html.php';
    exit();
}

header('Location: .');

exit();