title: How do I overlay an image in .NET
body: <p>I have a .png image i wish to overlay on a base image. </p>
  
  <p>My overlay image contains just a red slant line. I need to get the red line overlayed on the base image at the same co-ordinate as it is in overlay image. </p>
  
  <p>The problem is I do not have the co-ordinates location. </p>
  
  <p>I need to find it programmatically with C#. The overlay image will always be transparent or of white background. What code to find the line co-ordinates from overlay image?</p>