Crowdsourcing app Leafsnap puts people in touch with nature

Leaf of Tuliptree (Photos: Leafsnap)

If you've ever wondered what kind of tree you were wandering past, finding out is just a smartphone snapshot away.

Enter Leafsnap, a free app that serves as a digital field guide by matching photos you take with your iPhone or iPad (an Android version is in the works) against a database of high-resolution images of leaves, flowers, bark, and other parts of trees.

From facial recognition to tree identification

Leafsnap uses visual recognition technology developed at the University of Maryland and Columbia University, coupled with the botanical expertise of the Smithsonian Institution and the photography of non-profit group Finding Species.

So how exactly do you use Leafsnap? This video provides a pretty nifty overview:



The response to Leafsnap has been "overwhelming"

W. John Kress, chief botanist at the Smithsonian's National Museum of Natural History, said the response to Leafsnap since its May 1, 2011 launch has been "overwhelming." Over half a million apps have been downloaded and over a million images have been submitted to date.



Database to expand from 200 to 800 species - and counting ...

Leafsnap at present features trees found mainly in the Northeastern United States. Someday it will cover all of North America - and maybe even span the globe.

New York's Central Park and Washington's Rock Creek Park, the initial regional focal points of Leafsnap's developers, are home to some 200 of 800 types of trees found across the country, said Kress.

Leafsnap users act as "citizen scientists" that crowdsource plant growth patterns

Flower of the Black Locust

Whenever someone takes a snapshot and sends it to Leafsnap, "it is uploaded to a server at Columbia," said Kress. This ongoing process, in turn, fuels "the crowdsourcing of plant identification."

The upshot, as industry website crowdsourcing.org has put it: "Leafsnap turns users into citizen scientists, automatically sharing images, species identifications, and geo-coded stamps of species locations with a community of scientists who will use the stream of data to map and monitor the ebb and flow of flora nationwide."

Like the "Circle of Life" celebrated in "The Lion King," Leafsnap has fostered a "Circle of Science" that connects researchers with average, smartphone-wielding citizens.

Fine-tuning of app foreseen, funding biggest roadblock

David W. Jacobs, a computer science professor who led the team that wrote the algorithm for the app at the University of Maryland in College Park, said some fine-tuning of Leafsnap is foreseen.



Yet the biggest roadblock to moving forward is funding. Leafsnap was spawned by a multi-year research project sponsored by the National Science Foundation. Before this $2-million-plus grant ran its course, smartphones started making a splash on the mobile market. So a project initially aimed at scientists was re-purposed to develop a smartphone app.

W. John Kress displays a Leafsnap image on his iPhone
in his office at the National Museum of Natural History.
(Photo by Karen Carstens)

"I knew nothing about apps - I'm a botanist," said Kress. "And it was so nice to work with these people (computer scientists) ... finally we honed it down to this beautiful little thing called an iPhone."

Expanding Leafsnap to more tropical climes, however, poses a major challenge. The reason? The "veinatian patterns" - literally the "veins" of the leaves - are more detailed. "So we would need more detailed images," said Kress.

Jacobs said the technology is in place to tackle such problems: "We feel pretty confident that if we had the funding, we could do this."

The first in a series of digital field guides?

Leafsnap might moreover serve as a model for similar apps. Jacobs and his counterparts at Columbia have, for instance, created a method for identifying dog breeds. This program could function as a "test bed" to develop new apps which could differentiate various types of fauna, such as birds or insects.

Additional funds would also be required to develop an app specialized enough to pinpoint a particular type of insect clinging to a leaf, Jacobs added. Such innovations could however become paramount to particular "user communities," such as farmers trying to prevent pests from damaging their crops.



Leafsnap brings science to a much wider - and younger - audience

European Larch Flower

Meanwhile, Leafsnap has sparked some of America's most inquiring minds.

"The Smithsonian has been very excited about this app, about bringing our science to a much wider audience," said Kress.

A teacher in New Jersey, for instance, sent him an email that included a photo in which a group of second graders are sprawled across a classroom floor with a bunch of leaves and iPads.

"You have changed my students lives," she wrote, adding that these kids were eagerly awaiting the introduction of a "Spidersnap" or a "Bugsnap" app to identify creepy crawly critters.

"That was just kind of cute and just what we want our app to be," said Kress.