Digital Measurment Estimator

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.

Step 1: Reference Object

Now that I have something I want to measure I need to have a reference object. I happened to use a framing square in this instance. I propped this up against the garage door, this can be seen at the lower left hand corner. This framing square measures 24 x 16 inches.

From here on out it starts to get in depth. I will divide this up into two sections. One for the casual reader and one for the techno / geek / engineer in all of us.

CASUAL:
The idea of this project is to scale up a known size to determine an unknown size.

TECHNO, GEEK, ENGINEER:
Of course the accuracy in doing this will be largely affected by a multitude of variables, not all of which I can or will address, but I will try to explain a few. Please remember I am not an expert so those of you that are, please enlighten me on my mistakes.

Comments

[WingDings]

You'll also find that there's a certain position on your camera's zoom (assuming it has a zoom) that gives minimal image distortion (barrel or pincushion distortion), and so straight lines will appear straighter in the final image. Using that zoom setting and standing directly in front of the item to measure should give more accurate readings.

[dragonslaver99]

great instructable:) i vote for you:)

[LinuxH4x0r]

Great instructable! This works really great most of the time

[xtank5]

I noticed you took the picture from a slight angle. You should take your pictures from straight onto avoid the perspective. You may notice that your garage door gets skinnier towards one end. That could really throw off your estimations. Just thought that might help. Although I noticed you already wrote that I thought I would explain that.