title: How can I check if a PictureBox's image has been modified?
body: <p>I'm working on a super top-secret application right now that has a PictureBox on it.  There are some options to edit the image inside of the PictureBox, including (but not limited to) sepia, grayscale, and some rotations.</p>
  
  <p>At the moment, however, there isn't any way to check if the image has been modified - as I've been trying to create a "Would you like you save your changes??!" dialog box, which would appear if the image has been modified in any way.</p>
  
  <p>I've got all of the actual <em>modifications</em> set in stone at the moment - all I need is a reliable method of checking if the PictureBox's image has been modified.</p>