Counting L.A.'s Trees

Professor Pietro Perona, has developed a method using Google Earth and Google Street View to count the trees in the city of Los Angeles. The process of counting the trees using human tree counters is very expensive and would cost about $3 million today. The last time the city did such counting was more than two decades ago and at the time there were 700,000 street trees. 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. [LA Times story] [KPCC story]