message: Fix image uploading failure for OpenCV.js tutorials
diff: @@ -12,7 +12,7 @@ function Utils(errorOutputId) { // eslint-disable-line no-unused-vars
  onloadCallback();
  });
  script.addEventListener('error', () => {
  - this.printError('Failed to load ' + OPENCV_URL);
  + self.printError('Failed to load ' + OPENCV_URL);
  });
  script.src = OPENCV_URL;
  let node = document.getElementsByTagName('script')[0];
  @@ -99,7 +99,7 @@ function Utils(errorOutputId) { // eslint-disable-line no-unused-vars
  let inputElement = document.getElementById(fileInputId);
  inputElement.addEventListener('change', (e) => {
  let imgUrl = URL.createObjectURL(e.target.files[0]);
  - loadImageToCanvas(imgUrl, canvasId);
  + self.loadImageToCanvas(imgUrl, canvasId);
  }, false);
  };
  