get image file width javascript

JavaScript
<!DOCTYPE HTML>
<html>
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    <title>Get image width using File API</title>
  </head>

  <body>
    <input type='file' onchange="readURL(this);" />

    <script>
      function readURL(input) {
        if (input.files && input.files[0]) {
          var reader = new FileReader();
          reader.onload = function (e) {
            var img = new Image;
            img.onload = function() {
              console.log("The width of the image is " + img.width + "px.");
            };
            img.src = reader.result;
          };
          reader.readAsDataURL(input.files[0]);
        }
      }
    </script>
  </body>
</html>
Source

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