Have you ever wanted to get an approximate measurement from a digital photo and never knew how. Here is one way to do this. I completed this instructable using three items. 1) Framing Square (24 x 16 inches), 2) Digital Photo, 3) MS paint. I saw this software program on the internet at: http://www.stickyyard.com/ I wanted to challenge myself to see If I could recreate the function without the expense. Soo.. Here it goes. Please keep in mind that this is only an estimator and will not provide precision measurements. There are many factors that could affect your results. This should get you close if you do not have any other tools available. Here is my first subject, my garage door. I want to find the length and the height around the frame of the door.
http://www.instructables.com/id/Digital-Measurment-Estimator/