LVFree Vision Enhancer

智能手机应用程序，用于改善低视力人士的视觉能力。

Real-time electronic image processing is a promising approach to improve the visual capability of individuals with low vision. While several head-mounted video goggles are commercially available, they all cost at least several hundred dollars. Thus we have developed this free and simple app, LVFree Vision Enhancer, which is compatible with most camera-equipped smartphones running Android 7 or later. LVFree Vision Enhancer uses mathematical algorithms to process, in real time, the visual scene captured by the camera, and displays a modified version of that scene on the phone’s screen. LVFree Vision Enhancer features four image-processing settings:

Medium magnification

High magnification

Brightness enhancement (at medium magnification)

Reverse contrast (at medium magnification)

A phone running LVFree Vision Enhancer can be viewed either directly, or via a Google Cardboard-like virtual reality headset. In the direct viewing mode, the processed scene fills the entire screen. In the headset viewing mode, the processed scene is duplicated and displayed on the left and right halves of the screen, which are subsequently combined by the headset into a single stereoscopic imagery.

Each time you launch LVFree Vision Enhancer, an instruction screen is first displayed for 7 seconds, after which you can press either the volume down button to toggle through the four direct viewing settings, or the volume up button to toggle through the four headset viewing settings. To use the headset viewing mode, mount the phone onto a Google Cardboard-like virtual reality headset, making sure the headset is able to expose the phone’s camera. For prolonged use, we recommend headsets with soft padding as they are more comfortable than those without padding.

LVFree Vision Enhancer is best used when you are not moving. It helps you read medications at home, price tags at supermarkets, and menus at restaurants. Never use LVFree Vision Enhancer for walking around or driving. If you need to increase the ambient light level while running the app, many phones allow you to turn on the flashlight via the notification menu that slides out from the top edge of the screen.

The development of LVFree Vision Enhancer was funded in part by a Promobilia Foundation (Sweden) grant awarded to researchers in the Ophthalmology, Mathematics, and Neurology departments at the University of Michigan.