Following a New York Times article about billboards with facial-recognition-based tracking systems — which caused a privacy stir — TruMedia Technologies sent a letter to the paper explaining it would never record or store any video from the billboards, MediaBuyerPlanner reports.

TruMedia's billboard technology only analyzes the images its cameras take. No individually identifiable info is stored, according to the letter.

The camera-equipped billboards — inspired by Israeli surveillance — track faces to gather data for digital displays and screens.

"New York Times Reporter Stephanie Clifford" — who wrote the original NYT article — "rightly states, 'In advertising these days, the brass ring goes to those who can measure everything,'" the letter reads.

It goes on, "Ms. Clifford is 100 percent correct. With the increased popularity of out-of-home advertising and the exponential growth of the digital signage industry (translating into billions of dollars), there has been no accurate measurement system in place. Television has Nielsen and radio has Arbitron, but the out-of-home industry has grown up quickly without an accurate and reliable third-party measurement solution. Our company, TruMedia Technologies, realized that need and has created a robust, scalable, turnkey audience measurement solution."

TruMedia claims to be "working closely" with the Out-of-Home Video Advertising Bureau to help develop a comprehensive set of standards that address both methodology and metrics for the out-of-home measurement industry, including the buying, planning and selling community.

"Within those standards will come a quality control element that every vendor and advertising agency must agree to in order to use our products and services," it said.

Engadget includes the entire text of the letter.