We implemented a visual-based positioning system on the Android smartphones. This system uses only the build-in camera and sensors in a smartphone. The system works without additional assisted equipments, so it is very easy to deploy to consumers with mobile devices. In addition, we conducted small and large-scale field experiments to examine the accuracy of our system. The results indicate that our system is able to provide a much better accuracy in small-scale experiments compared with the global positioning system. In large-scale experiments, the system is accurate enough for virtual augmentation and location-based service applications.