The US Internet colossus said it was testing the technology in updated
"Street View" pictures woven into its map of Manhattan and, if successful, would put it to work across its mapping website.
While blurring faces may reduce complaints that snapshots of street life posted with Google Maps results could violate people's privacy, that is not the motivation for applying the technology, a Google spokeswoman told AFP.
"It is something we have been looking into for quite some time," she said.
"The purpose of Street View isn't looking at people, it's looking at buildings and locations. Obviously, we want to take steps in protecting people's privacy, but from the beginning we've been committed to doing this."
Google has been working for a year on a way to automatically detect and blur faces in pictures, company software engineer Andrea Frome wrote in a Google blog post.
"Working at Street View-scale is a tough challenge that required us to advance state-of-the-art automatic face detection," Frome wrote.
"We continue working hard to improve it as we roll it out for our existing and future imagery."
Frome pointed out that Manhattan street view pictures were also modified to allow people to look up to admire skyscrapers and the cityscape.
Street View photos were added to Google online maps of major US cities a year ago.