This tutorial is available as a PDF. Click here to view or download     Pictures Side-By-Side / "Before and After" Images This question comes up in the GD&Q fairly often. 1- Open your "Before" picture with paint.net.   In the Status Bar, set the Units to Pixels     The pixel dimensions of the image are shown in the Status Bar (800x600 in the image above). Take note of the image size.   Click on the Image menu   ==