Map features represent objects that Mapillary has detected in images and placed in a 3D space. Using computer vision, we recognize objects within images (available as object labels). Next, by reconstructing the 3D scene structure, we can position these objects on the map as map features. Currently, you can retrieve traffic signs as point features, and additionally explore a number of line features in beta. (Read more on each of those below.)
Characteristics of map features
When retrieving map features as a dataset, you will get the type of the map feature and its GPS position (latitude and longitude) in a standard geospatial format (shapefile or GeoJSON).
There are two important notes on map features.
- To estimate the location of the object on the map, the object needs to be detected in two or more images. The positions of the images are then used to calculate the position of the map feature. Keep this in mind when choosing the interval of the images you capture—more images means more data points to triangulate the position of the object more closely.
- The accuracy of the location of the map feature will be influenced by the accuracy of the location of the images. This is contingent on the GPS accuracy of your phone, camera, or GPS device. If high-accuracy positioning is a requirement, you might consider professional devices with enterprise-grade GPS capabilities.
Mapillary extracts more than 900 types of traffic signs in 67 countries as point features on the map. That means, we provide the estimated coordinates of the traffic signs based on the positions of the images that we've detected the signs in.
For more information, see the list of detected traffic signs, and the instructions for exploring traffic signs on the Mapillary web app.
Line features are a map representation of line-shaped real-life objects, such as lane markings, rail tracks, and curb cuts.
Line features are matched against existing map data. The features currently available on Mapillary have been aligned with the OpenStreetMap road network but our processing system has been built so that it can utilize any map data to match against. This means we will be able to extract line features aligned to any road network data in the future.
Take a look at the article about exploring line features on the Mapillary web app.
The following objects can be extracted from Mapillary imagery as line features:
- service lane
- traffic island
- dashed lane marking
- solid lane marking
- bike lane
|- curb cut
- rail track
- road shoulder
- other barrier