impossible for someone who does not pick up much of the contextual mostly visual information provided by the environment. For instance, if a person found him/herself in a random building, a quick glance around the current location tells a lot already about the building. Things such as signs, furniture, corridors and staircases, and the view from windows can tell about the purpose of the building, and a location can be approximated from the outside view. Most of this information will be completely missed by someone who cannot pick it up with the eyes, and so a major challenge is to design a system that can transmit this information, or provide the knowledge in another way. A blind person navigates in a highly structured manner using both physical and artificial landmarks. Examples of the former include walls, pavement edges, material changes and auditory information such as the beeps of a traffic light or how the sound reverberates in the location. Artificial landmarks are, for example, ''third door on the left'' when walking in a corridor. Since route familiarity is important, it is desirable to reuse as much of a route as possible, because straying from the path might means probably a complete loss of the route. If this should happen, it is important being able to retrace back to a known landmark in order to regain the sense of location and orientation. Routes that stay fairly static might often be preferred because of the lower risk of encountering a large obstacle forcing a different route. Unless the visually impaired person walks with someone else, there are two widely employed solutions to make navigating easier: the white cane and the guide dog. They both provide basic assistance in avoiding obstacles and detecting stairs. Though the guide dog can learn routes and help much more than the cane when something has changed along the route. The cane on the other hand is very simple and is intuitively to use because it behaves like an extended arm. Because of this, it is easy to trust completely in the information the white cane provides. Aside from the white cane or the guide dog, some navigation systems (known as electronic travel aids, ETA's) specifically designed for the visually impaired are available [5]. These range from simple sound-emitting beacons that can be positioned in strategic places of the environment, to Smartphone's with GPS. This can be useful at a high level but it has some major disadvantages. Firstly it is based on static maps and therefore cannot provide dynamic information on-the-fly, and secondly it does not work indoors. The GPS devices that are tailored for the visually impaired, like they usually have some extra features like easy tagging of locations, route logging and retracing functionality, and a ''where am I?'' feature which tries to describe the current location in terms of tagged locations around it [4].