Can a phone measure distance like a ruler?
But can a smartphone replace more conventional tools like a tape measure, for example? With all the wizardry happening behind smartphones’ camera systems, this task should be an easy one for our predators, right? Well, I decided to find out.
Android: Is Google Measure accurate?
After a quick research, I downloaded the first app that Google suggested called Measure. I figured that people in need of a ruler or a tape measure app would probably do the same thing. Armed with the real thing and my carnivorous phone, I roamed the office to check out how good and how precise this app actually was.
Before we delve into the matter, let’s take a look at the Measure app. Here’s the description, taken from the Play Store: “Measure helps you with quick everyday measurements around the house or office, similar to a tape measure.”
Google advised me to “move the phone around the space to find flat surfaces such as a tabletop or the floor. Point and tap to start your measurement and adjust it accordingly.” This app works with phones running Android 7 or higher and Google’s AR Core on board. Right! Time for some fieldwork.
The first thing I noticed is the simple interface of the app. It’s almost barebone. It turns on the camera and tells you to move your phone from left to right, in search of a flat surface. When you find one, the white circle in the middle of the screen will turn orange and a dot will appear inside.
You can then choose the starting point of your measurement. A virtual line will appear on the screen showing the distance in real-time as you move the phone. You can finish the measurement by tapping on the big gray button on the right and then you can take a picture of the result.
- Measure app doesn’t like reflective surfaces
- It’s not very fond of black ones either
- The closer you are to the object, the more precise the measurement
- At a distance of about three feet, the deviation is less than an inch
- You have to face the object of measurement, any angle will produce false results
- Vertical measurements and empty spaces are tricky
Download Google Measure on the Play Store
iOS: How accurate is the iPhone Measure app?
iOS devices enjoy the luxury of having a preinstalled measurement app, called Measure (no bonus points for originality) since iOS 12. This saves the hustle to search and download a third-party app (although Google might decide to bake its own measuring tool inside future Android releases).
Before launching the app, I decided to check the description on the App Store. “Turn your iPhone or iPad into a tape measure with Measure. Measure enables you to quickly gauge the size of real objects, a person’s height, and it can automatically provide the dimensions of rectangular objects.” Pretty much the same as Google Measure with the exception of the ability to measure rectangular objects automatically.
There are no specific instructions for the measurement process on the App Store, and I couldn’t find any dedicated help section in the app either. Well, how hard can it be? I just launched the app and tried to measure a couple of objects. There are messages that appear on the display, telling you what to do, and the interface is simple, yet it feels a bit more refined than the one found in Google’s counterpart app.
Measurements are taken the same way as with the Google Measure: find a flat surface, then choose an anchor point, tap on the plus button, move the phone, tap on the button again, and voila! Unlike Google Measure, the iPhone’s app tends to automatically anchor the starting point to an edge or a high-contrast zone. That’s very helpful at times, and equally annoying when you don’t need the anchor.
iOS Measure can detect rectangles and automatically give you dimensions (including surface area). It’s a very handy option, given that most of the things in our homes are, well… rectangular. Fridges, tv sets, wall paintings, picture frames, tables, you name it. The caveat is that Measure is not very accurate. Just like Google Measure, the iOS tool works best at a close distance (it even advises you to move closer at times). When you move a meter away, things start to deviate. I noticed that most of the time iOS Mesure tends to be quite generous with dimensions, giving larger numbers than the reference tape measure.
- iOS Mesure is faster (than Google Measure) and the interface feels more refined
- You still have to be relatively close to get the best results
- It can tackle some reflective and black surfaces
- At a distance of about three feet, the deviation is sometimes more than an inch
- The feature that measures rectangular objects automatically is fun, but sadly not very precise
Download Measure app on the App Store
Can a phone measure distance like a ruler or tape measure?
And the winner is... the tape measure. Neither of these apps is accurate enough to measure any critical stuff. You can get an estimate and if one or two inches don't matter, I guess both apps can do the job. Just don't try to build a house using either of them. iOS Measure feels more advanced, though, and works pretty fast. It can tackle some reflective and black surfaces, but the problem with precision remains. So, at the moment your good old tape measure is your best friend when it comes to precise measurements. Technology can catch up, though, with the current rates of development, so don’t write that one off, yet.