National Center for Biological Sciences
Black Spot: a platform for automated and rapid estimation of leaf area from scanned imagesVarun Varma, Anand M. OsuriPlant Ecology, 2013 View paper
Other tools for the analysis of leaf:
Black Spot is a free stand alone software and method to estimate leaf area from images of leaves captured using any standard flatbed scanner. This easy to use software allows the user to batch process a large number of samples across multiple species with minimal user input.
Source: Black Spot website