Upload Image from URL OR Convert Image URL into base 64 by Javascript

function getBase64ImageFromUrl(image_url){      var canvas = document.createElement("canvas");      var ctx = canvas.getContext("2d");      var img = new Image();      img.src = image_url;      canvas.width = img.width;      canvas.height = img.height;      ctx.drawImage(img, 0, 0);      var data = canvas.toDataURL("image/jpeg");
      return data;

}

OR

    var canvas = document.createElement("canvas");
    var ctx = canvas.getContext("2d");
    var img = new Image();
    img.onload = function () {
        canvas.width = img.width;
        canvas.height = img.height;
        ctx.drawImage(img, 0, 0);
        var data = canvas.toDataURL("image/jpeg");
        alert(data);
    };
    img.src = "http://localhost/MvcApplication3/test.png"; 

OR 

 function getBase64ImageFromUrl(image_url){ 

  var canvas = document.createElement("canvas"); 

  var ctx = canvas.getContext("2d"); 

  var img = new Image();  img.src = image_url; 

  canvas.width = img.width; 

  canvas.height = img.height; 

  ctx.drawImage(img, 0, 0); 

  var data = canvas.toDataURL("image/jpeg"); 

  return data;}

imgObj = $(this).parent().find('img');img = getBase64ImageFromUrl(imgObj[0].src)

 function getBase64ImageFromUrl(image_url){  var canvas = document.createElement("canvas");  var ctx = canvas.getContext("2d");  var img = new Image();  img.src = image_url;  canvas.width = img.width;  canvas.height = img.height;  ctx.drawImage(img, 0, 0);  var data = canvas.toDataURL("image/jpeg");  return data;}