You type a word or phrase into an Internet search engine such as Google or Yahoo, hit retu

rn and in an instant, dozens of "hits" -Web sites containing words that match your query-appear on the computer screen. Now imagine a similar database that operates not with words but with shapes, specifically, leaf shapes. It would work like this: carry a camera cell phone into a forest, pick a leaf from a tree and snap its

portrait. [1] In an instant, the phone transmits the image to a computer that matches a shape of the leaf

against a database of leaf shapes from thousands of plant species around the world. Exact matches for the leaf are returned to the screen of your phone along with species names and detailed botanical information. Sound farfetched？ Such a device is already very close to reality, thanks to recent collaboration between the department of botany at the Smithsonian&39;s National Museum of Natural History and the computer science departments of Columbia University and the University of Maryland. [2] Tentatively called the Image Identification System or IIS, the invention has the potential to revolutionize the identification of plant species in the field and greatly accelerate the naming of new plant species.

[3] For Peter Belhumeur, a computer scientist at Columbia University, who studies the use of computer vision to identify human faces, it all started years ago in the Connecticut woods. Belhumeur recalls just how hard it was to use a standard field guide to identify different tree species during walks with his children. "I rarely found the right answer on the first try," he says. Brainstorming with computer scientist David Jacob of the University of Maryland about possible new uses for computer object recognition, "We both thought of leaves," Belhumeur recalls. So in 2001, [4]Belhumeur and Jacobs came to visit John Kress, Director of the Natural History Museum&39;s Botany (植物学) Department, which house the national plant specimens, a resource with 95,000 catalogued botanical type specimens ----the definitive reference specimens used to identify new plant species ---- and an additional 4.8 million representatives of plant species from around the world.

[5] What the scientists came up with was an ambitious plan to develop an electronic field guide---- a

portable system that could automatically identify a tree species from the shape of one leaf. They wanted the device to simultaneously provide researchers in remote locations Internet access to botanical data on species in the Smithsonian&39;s database.