Finding your way across an unfamiliar city is a challenge for most people鈥檚 sense of direction. Software that generates personalised maps showing only relevant information, and carefully chosen views of selected landmarks, could make disorientation a thing of the past.
Thanks to online services such as and maps now contain more information than ever. It is possible to toggle between a regular schematic, a 鈥渂ird鈥檚 eye view鈥� that uses aerial photos and even three-dimensional representations of a city鈥檚 buildings.
Those multiple perspectives can help users locate themselves more accurately. But there is a risk of overloading the viewer with information, says at the University of California in Berkeley.
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鈥淲hen the maps show every building, every street, it鈥檚 very difficult to find specific sites,鈥� she says. They are also unsuitable for using when actually walking around.
Grabler has built software to let people generate maps for places they鈥檙e going that display just the essential information 鈥� projections of landmark buildings, along with clear views of the major roads.
Direct route
Grabler鈥檚 team at Berkeley, working with researchers at , used a perceptual study of San Francisco from the 1960s to help identify which landmark buildings to include on a map of the city.
They found that landmark buildings came in three varieties. 鈥淟andmarks can be semantic 鈥� for instance, a theatre is a cultural landmark,鈥� says Grabler. 鈥淭here are also visual landmarks, with a colour and shape that makes them distinctive, and structural landmarks with a strategic position: on the edge of a square or at an intersection.鈥�
These categories were used to give each building in San Francisco a rating on the basis of its score in each of the three categories. Only those that scored above a threshold value were then displayed on the final map.
All-round view
When generating a map, the user can choose to display those landmarks in one of two ways. They can be displayed as straightforward three-dimensional depictions, but that masks the buildings鈥� facades.
To provide the user with more information, Grabler鈥檚 team added an oblique projection option, which shows all visible sides of the building. Although the buildings look distorted compared with a regular three-dimensional depiction, it is possible to see all the facades a building presents to the street, including both facades for a building on a corner.
But buildings depicted this way can hide some streets. This is avoided by widening the map鈥檚 roads, and shrinking the height of the buildings so that roads remain visible behind even tall buildings.
The user鈥檚 final decision is to choose the purpose of their map. On a shopping map, all the major shops become semantically important and are included on the map. A food map, by contrast, will show fewer shops but more of the city鈥檚 restaurants.
Grabler鈥檚 team has yet to test their maps on San Franciscan tourists, but she told New 杏吧原创 that Microsoft has expressed an interest in incorporating her ideas into Microsoft Live maps.
Grabler presented her research at the in Los Angeles last week.
