Ready for a smellfie?

Published Jun 10, 2015, 4:43 am IST
Updated Mar 28, 2019, 10:36 pm IST
How your nose can help urban planning or even find the best route

Selfies will soon become passé if photo captions on visual social networks like Flickr and Instagram can be used to create detailed smell maps of urban areas. A team led by Daniele Quercia at the University of Cambridge used data taken from the sites to plot maps of aroma distributions across whole towns and cities, from the stench of sewer vents and horse dung to fragrant fruit markets, the new-mown lawns of public parks and the garlicky whiff of restaurant districts reports

The system might lead to some unusual location-based technology: automatically generated online maps that let us plot routes not by shortest distance, but by the smells we prefer to experience (or avoid) on a walk, jog or bike ride. The name for these personalised maps? “Smellfies”.


The research is based on the manually produced urban smell maps and aroma lexicon developed over the last three years by artist and designer Kate McLean of the Royal College of Art in London — a member of Quercia's team.

A smell dictionary
McLean has been taking volunteers around cities like New York and Amsterdam, getting them to agree on smells at certain points — sniffing everything from garbage to manhole covers to park benches — and plotting maps. This enabled her to create a “smell dictionary” of 285 words commonly used to describe urban smells. But mapping them manually is slow work.


The researchers reasoned that the captions and tags that people add to their geotagged online photos on Twitter, Instagram and Flickr might offer a faster way to build smell maps.

So for Barcelona and London, the team collected geo-referenced tags from about half a million Flickr pictures and 35,000 Instagram photos as well as 113,000 Tweets. The tags and Tweets were matched with words in the smell dictionary. “We simply looked for the keywords Kate has identified in the picture captions and tags on their photos,” Quercia says.

The smell maps were presented at a conference in Oxford this week. Flickr and Instagram worked best, probably because they have a formal captioning and tagging structure, whereas Tweets mentioning smells tended to be far more general in scope and not as area-specific.

A city’s ‘smellscape’

The maps provide an entire “smellscape” of a city, and one that can be changed to plot the smells most apparent at different times of the year, which might be useful for tourism planning. “We also tried correlating the data with known air quality indicator data in London and found that pleasant nature-related smells were suppressed by air pollution,” says Quercia. The team hope the findings will help urban planners better manage air quality and expand their monitoring of airborne pollutants. The team plan to launch Smelly Maps, a website where you can tailor your own olfactory experience, or smellfie, in the next six months.