Columbia University, the University of Maryland, and the Smithsonian Institution
Leafsnap: A Computer Vision System for Automatic Plant Species IdentificationNeeraj Kumar, Peter N. Belhumeur, Arijit Biswas, David W. Jacobs, W. John Kress, Ida C. Lopez, João V. B. SoaresComputer Vision – ECCV 2012, 2012 View paper
Other tools for the analysis of leaf:
Leafsnap is the first in a series of electronic field guides being developed by researchers from Columbia University, the University of Maryland, and the Smithsonian Institution. This free mobile app uses visual recognition software to help identify tree species from photographs of their leaves. Leafsnap contains beautiful high-resolution images of leaves, flowers, fruit, petiole, seeds, and bark. Leafsnap currently includes the trees of the Northeast and will soon grow to include the trees of the entire continental United States.
Source: LeafSnap website