To do this you need to have installed the Google Translate application from Play Store and Apple Store to have an internet connection. Now it is simple to read unknown words from a restaurant menu, or traffic indicators or other else documents or outdoor prints. While using the Translate app, just point your camera at a sign or text and you’ll see the translated text overlaid on your screen.
The instant translate feature of Google Translate app for smartphone is now available in 36 languages.
See below an example of how to do that.