The Leafsnap App Helps You Identify Every Tree in NYC

As the leaves change colors and fall to the ground, the best way to enjoy the warm hues is to head to the park. But do you have any idea what trees those leaves came from? Don’t worry, there’s an app for that. <a href="http://leafsnap.com/" target="_blank">Leafsnap</a>, created through a collaboration between <a href="http://inhabitat.com/nyc/6-ways-to-have-eco-friendly-fall-fun-in-nyc/www.cs.columbia.edu/~belhumeur/" target="_blank">Columbia University</a>, the <a href="http://www.cs.umd.edu/~djacobs/" target="_blank">University of Maryland</a>, the <a href="http://botany.si.edu/staff/staffPage.cfm?ThisName=2&amp;homepage=no" target="_blank">Smithsonian Institute</a>, and <a href="http://findingspecies.org/" target="_blank">FindingSpecies.org</a>, uses visual recognition algorithms to identify fallen flora. The app is geared toward us urbanites, as it currently includes <a href="http://leafsnap.com/species/" target="_blank">tree species</a> in New York City, Washington, D.C., and parts of the Northeast.

The free <a href="http://leafsnap.com/" target="_blank">Leafsnap</a> app is the first of a series of digital field guides using visual recognition to identify plants and species. To find out what tree you're looking at, all you have to do is take one of the leaves (preferably one that has fallen on the ground... no need to pluck fresh ones from the branches!), place it on a clean, light colored background, and snap a photo. <a href="http://www.fastcodesign.com/1663926/wanted-leafsnap-app-lets-you-id-trees-using-face-recognition-tech" target="_blank">The app</a> tells you whether it’s a <a href="http://en.wikipedia.org/wiki/Platanus" target="_blank">sycamore</a> or <a href="http://en.wikipedia.org/wiki/Elm" target="_blank">elm</a>, along with providing high-res pictures of the tree’s flowers and other characteristics.

The visual recognition algorithms are the key to Leafsnap's abilities. "Each leaf photograph is matched against a leaf-image library using numerous shape measurements computed at points along the leaf’s outline," writes <a href="http://smithsonianscience.org/2011/05/new-mobile-app-that-identifies-plants-by-leaf-shape-launched-by-smithsonian-and-columbia-and-maryland-universities/" target="_blank">Smithsonian Science</a>. "The best matches are then ranked and returned to the user for final verification."

“Within a single species leaves can have quite diverse shapes, while leaves from different species are sometimes quite similar,” said <a href="http://smithsonianscience.org/2011/05/new-mobile-app-that-identifies-plants-by-leaf-shape-launched-by-smithsonian-and-columbia-and-maryland-universities/" target="_blank">David Jacobs</a>, a professor of computer science at the <a href="http://www.cs.umd.edu/~djacobs/" target="_blank">University of Maryland</a> who helped create the software. When you select a leaf on the app, it brings up details about the tree.

“One of the main technical challenges in using leaves to identify plant species has been to find effective representations of their shape, which capture their most important characteristics,” said Jacobs. Selecting a leaf also brings up variations of how this leaf looks on the tree and other characteristics that will help you identify it.

You might be thinking, "what's wrong with a good old fashion field guide book?" The thinking behind <a href="http://leafsnap.com/" target="_blank">Leafsnap</a> was that you often don't find what you're looking for by flipping through a book. If you have no idea where to start, you'll be searching for ages. With <a href="http://leafsnap.com/" target="_blank">Leafsnap</a>, you identify the tree and learn about its properties in a matter of seconds.

Like any good app, <a href="http://leafsnap.com/" target="_blank">Leafsnap</a> connects you to a larger picture. As you snap photos, the information is sent to a community of scientists who will use the information to map and monitor the population and growth of trees around the country. While the app is specific to the Northeast right now, soon the app will include information on all tree <a href="http://leafsnap.com/species/" target="_blank">species</a> found in the United States.