How to use any smartphone as a ruler

Engineers are increasingly using the video capabilities of smartphones to create 3D images. Researchers from Carnegie-Mellon University in Pittsburgh have now found a way to use a smartphone component to provide accurate measurements of these models.

All smartphones today are equipped with devices called IMUs (inertial measurement units) which switch the display between portrait and landscape formats depending on how the phone is being held. Researcher Simon Lucey at Carnegie-Mellon’s Robotics Institute has found that IMUs can also calibrate 3D models as they are created and enable the phone to obtain accurate measurements from them.

Working on a system to help people obtain the right size glasses by using their phone camera to take pictures of their faces, Lucey and his team, working with colleagues at the University of Queensland, found that IMUs can be used to track the camera’s motion as the user moves the phone around to capture various facial angles.