This week, Google launched the Street View in India, which shows you 360-degree panoramic photos of the place you have searched for on Google Maps. MapmyIndia launched Mappls, whose street view feature is called RealView. While Street View is available in 10 cities, to begin with, and more cities will be added, Mappls RealView covers far greater number of cities and even rural areas.
How are images collected?
To find out how do these photo-based maps work and what benefits do these bring to the users, we spoke to Prof Gitakrishnan Ramadurai, faculty in the Transportation Engineering Division, Department of Civil Engineering, IIT Madras.
“Google collects Street View imagery by driving, pedalling, sailing and walking around, and capturing imagery with special cameras that simultaneously collect images in multiple directions. The images are later overlapped and stitched together into a single 360-degree image,” Prof Ramadurai said. “In the case of urban Street View images you see on Google Maps on your phone, most of it is collected by a camera system mounted on top of a car, and these cars have been moving around the world for over a decade.”
According to Google, Street View cars have driven more than 10 million km in over 70 countries. The same camera system has also been mounted on tricycles, snow machines, boats, dog sleds and even the backs of camels to allow Google to travel across the world’s continents and in places where motor cars cannot reach.
Google doesn’t run its own vehicles fitted with cameras everywhere. It also partners with other companies who provide Google with images (like in India it partnered with Genesys International, an advanced mapping solutions company, and Tech Mahindra). It also crowdsources images.
“These images are connected to the GPS link of that area, and so whichever place you search for in Google, a photograph of that place will show up on Google Maps,” Prof Ramadurai said. “These millions of images are stored in the map provider’s server.”
Benefits for the user
As far as benefits to users are concerned, ‘street view’ adds a layer of assurance. “Street view is an add-on to digital maps (which are far more comprehensive). These give you a visual idea of a place you have searched for. Digital maps will show you which all restaurants are on a particular street, while street view will show you how the restaurant looks like from outside,” Prof Ramadurai said. “It is particularly helpful for people who are walking around or want to explore a place on foot.”
Challenges and accuracy
In a dynamic country like India, an image taken today might not hold true next year. Prof Ramadurai agrees: “With construction of metros, flyovers, buildings, etc, India is changing, but map providers don’t take responsibility for these images; they don’t say that it’s the current image. But, for example, in the US, Google has had a re-run of its cars taking images after a few years so that the most current photo of an area is displayed.”
Street view is different from the 3D digital replication of buildings that most map providers offer. “Those are far more complex, and use Lidar for imagery, unlike street view that uses a camera,” Prof Ramadurai said.