They don’t call your smartphone “smart” for no reason. These incredible pocket computers already do a lot, but researchers are working on even more amazing uses. Researchers have discovered a way to calculate accurate 3-D measurements using smartphone cameras.What that means for the future is pretty amazing.

Ever wondered how your cell phone or tablet knows to flip the screen when you turn the device? They use devices called inertial measurement units, or IMU. An IMU uses a combination of accelerometers and gyroscopes to detect motion, enabling not only screen rotation, but gesture recognition, gaming, step-counting, and even free fall detection.

Accelerometers are used to measure acceleration and tilt, and gyroscopes are used more for angular velocity and orientation. When these are combined into the IMU, a more complete understanding of orientation, position, and speed is gained. The typical IMU in a cell phone is cheap, mostly designed for screen rotation and such, but Carnegie Mellon University researchers have found that the IMU, combined with other technologies such as face tracking, could lead to some excellent applications.


Cell phone videos have been used often to create 3-D models of rooms and the world in general, but these videos have a problem with scale. By simply waving the phone around a bit while recording, it’s been found that these cheap IMUs allow for calibration of the 3-D models and provide more accurate measurements.

This could lead to a host of new uses. One use would be virtually shopping for eyeglasses. While there currently are programs that allow you to try on a pair of glasses, using your front facing camera, they cannot accurately depict the size of the glasses compared to your face. With this technology, you can accurately measure those frames and calculate whether they would actually fit your face.

Another use of this technology is as a simple but accurate ruler for small spaces. Using the IMU and the smartphones camera, researchers were able to pinpoint accurate measurements of an object’s size and scale. With improvements to the technology, you could create a 3-D model of a room and see if a couch or other piece of furniture will fit.


(Images courtesy of Carnegie Mellon University)

Even further down the road, if the technology can be enhanced to operate in real time, it could be used to create self-driving cars that are less energy consuming, and to improve virtual reality/augmented reality devices. It could even be used in robotics.

~ Audra