Serving Larchmont Village, Hancock Park, and the Greater Wilshire neighborhoods of Los Angeles since 2011.

Counting LA’s Trees

Trees along our parkways provide cooling shade, produce oxygen and give the neighborhood a green canopy of beauty.
Trees like these along parkways in Windsor Square help shade almost 40 precent of our neighborhood.

Fortunately, we have lots of trees in our neighborhoods. One study estimates about 40 of our neighborhood is covered with trees, compared to nearby Koreatown with only 7 percent.  But overall, trees cover only about 21 percent of the City of Los Angeles putting us well below the national average.

Now, after several years of drought, the number could be even lower despite recent efforts to plant trees. So, in an effort to get an accurate count of our urban forest, The LA Times reported this week “the city Bureau of Street Services has called on Caltech for help. And Caltech has called on Google.”

Not surprisingly, there’s a guy at Caltech… “Pietro Perona, an academic who hopes to become one of the world’s most prolific urban tree counters, has developed a method using Google Earth and Google Street View to let a computer do the counting,” according to the Times.

While the city is working out permissions with Google, Perona is teaching computers see trees according the LA Times:

Using the downloaded satellite view, Perona is teaching computers to record the latitudes and longitudes of shades and shapes that look like trees.

He then matches those coordinates to an image on Street View.

The computer examines the closeup to confirm the presence of a tree and judge its variety.

It takes a human years to learn the taxonomy of trees, Perona said. And it would take dozens of humans months to apply that knowledge to the city’s trees.

But a bank of computers could do it overnight, Perona said.

“Thirty-two CPUs. Sixteen square miles for one CPU,” Perona said.

Perona has tested the methodology in a section of Pasadena where the city recently commissioned a sidewalk survey. By comparing the results to the known inventory, he determined that the computer was about 80% accurate, reported the LA Times.

How cool is that?

Print Friendly, PDF & Email
Patricia Lombard
Patricia Lombard
Patricia Lombard is the publisher of the Larchmont Buzz. Patty lives with her family in Fremont Place. She has been active in neighborhood issues since moving here in 1989. Her pictorial history, "Larchmont" for Arcadia Press is available at Chevalier's Books.

Related Articles


Please enter your comment!
Please enter your name here


Latest Articles

.printfriendly { padding: 0 0 60px 50px; }