The free Leafsnap 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. The app tells you whether it’s a sycamore or elm, along with providing high-res pictures of the tree’s flowers and other characteristics.
You might be thinking, “what’s wrong with a good old fashion field guide book?” The thinking behind Leafsnap 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 Leafsnap, you identify the tree and learn about its properties in a matter of seconds.
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 Smithsonian Science. “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 David Jacobs, a professor of computer science at the University of Maryland who helped create the software. “So 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.”
Like any good app, Leafsnap 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 species found in the United States.
lead image © Liz West via Creative Commons