Google has acquired a seven-year-old company that develops facial-recognition technology for images and video, though the Web-search giant didn’t say what it plans to do with it.

The company, called Pittsburgh Pattern Recognition, or PittPatt, is run by three “image analysis” and “pattern recognition” specialists with PhD’s from Carnegie Mellon University, according to its site. Terms of the deal weren’t disclosed.

A statement on PittPatt’s site said on Friday that “computer vision technology is already at the core of many existing products” at Google, including Image Search, YouTube and Picasa, “so it’s a natural fit to join Google and bring the benefits of our research and technology to a wider audience. We will continue to tap the potential of computer vision in applications that range from simple photo organization to complex video and mobile applications.”

A Google spokesman said PittPatt developed “innovative technology” in the area of computer vision and that its research “can benefit our users in many ways,” without elaborating.

Regarding face recognition, the spokesman said, “We’ve said that we won’t add face recognition to our apps or product features unless we have strong privacy protections in place, and that’s still the case.”

Google has said it built facial recognition technology for smartphones into a product known as Google Goggles, but withheld it. “As far as I know, it’s the only technology that Google built and after looking at it, we decided to stop,” said Google Chairman Eric Schmidt last month at a conference. “People could use this stuff in a very, very bad way as well as in a good way.”

During its annual developer conference in May, Google showed off something called “Virtual Camera Operator,” which uses computer-vision technology to stabilize mobile video chats by following a person’s head movements and to determine who is speaking during a multi-person video conference so that the camera would automatically focus on the speaker.

It also recently launched Google+, a social network that lets people share and store photos, among other things. Rival Facebook has face-recognition technology to identify people in photos, which has raised concerns from privacy advocates. The technology, first introduced last year, was designed to help Facebook users easily identify and mark, or “tag,” friends in photos as they upload them to the social-networking site.

“If for any reason someone doesn’t want their name to be suggested” for tagging, “they can disable the feature in their Privacy Settings,” Facebook has said.

PittPatt’s software “accurately counts the number of people viewed by a video camera” and “it can automatically generate reports measuring the presence and movement of people over extended periods of time,” according to a cached version of its website.

Some of the “practical applications” of the technology include measuring “the effectiveness of digital signage, advertising, kiosks and narrowcasting”; “customer traffic flow,” or gathering “insight into customer behavior and shopping patterns; “security-related matters” such as being able to send alerts when the PittPatt software detects a face that isn’t in its database.

PittPatt offered a tool for people to “integrate face finding and tracking into your own product,” and in 2007 it partnered with General Electric to develop an “intelligent security camera system,” the site said. The GE system “will obtain high resolution facial imagery using a motorized pan-tilt-zoom camera that will track and zoom in on faces that enter the field of view,” according to the site.