title: Watermark an image upon download...is it possible?
body: <p>Simple question with yes/no answer and if yes...then how?</p>
  
  <p>Suppose you have an HTML page with an image on it without any sort of watermark.  </p>
  
  <p><strong>Is it possible to place a watermark on that image if a user saves it to their computer?</strong></p>
  
  <p>I need a simple function that watermarks an image upon download or save...</p>
  
  <p><strong>I do understand that once the image loads in the browser, it is technically downloaded, so is there a way to display the image without a watermark on screen, and if the user opens browser cache, he/she finds a watermarked copy?</strong></p>
  
  <p>If anybody has done this using any platform (PHP, GD, jQuery, etc.), your contribution would be appreciated.</p>