title: ImageJ: .show() does not show an image
body: <p>I very new to javascript and I would like to process some images in Fiji. I have been using the macro language for a while, but I am trying to get familiar with the formal ImageJ/Fiji API. I am trying to run the folowing simplistic piece of code, it runs with no errors but it does not show any image in the end. What's going wrong?</p>
  
  <pre><code>importClass(Packages.ij.plugin.filter.GaussianBlur);
  
  
  var image = IJ.openImage("/home/.../KNIIC_BC_Cam2_AirBubble2_Image1038.bmp");
  IJ.run(image, "8-bit", "");
  
  var dpl = image.getProcessor().duplicate();
  var gs = new GaussianBlur();
  gs.blur(dpl,20);
  new ImagePlus(gs).show();
  </code></pre>
  
  <p>Thanks in advance</p>