"Face recognition is hard."

The nation's top-level intelligence office, the Director of National Intelligence, wants to find "the most accurate unconstrained face recognition algorithm."

A branch of the office, which oversees the nation's spy agencies, is holding a contest toward that end, with submissions due no later than 2pm ET June 15.

"Have you developed software to identity faces in general web photographs? Can your software verify that a face in one photograph is the same as in another?" asks a posting on challenge.gov about the Face Recognition Prize Challenge. It continues:

The goal of the Face Recognition Prize Challenge is to improve core face recognition accuracy and expand the breadth of capture conditions and environments suitable for successful face recognition. The Challenge comes in two parts: 1) Face identification involves executing one-to-many search to return the correct entry from a gallery, if any; 2) Face verification requires the algorithm to match two faces of the same person while correctly rejecting faces of different persons. Both tasks involve “non-cooperative” images where subjects were unaware of the camera or, at least, did not engage with, or pose for, the camera.

The solicitation for contest entrants notes that "Face recognition is hard"—especially when factors such as "head pose, illumination, and facial expression depart from formal portrait photography standards."

You’re likely in a biometrics database

The government noted that there has been "enormous research" done in the field, and it wants "to know whether this rich vein of research has produced advancements in face recognition accuracy."

Facial recognition technology has become increasingly important to both the private sector and the public sector. Social-networking site Facebook is among the best known private-sector players in the field, especially when it comes to tagging people in photos.

For law enforcement, about half of all US adults have their images in a crime-fighting, biometrics database. That's about 117 million adults.

Overall, the FBI has access to about 412 million images as part of a face-recognition database, and the bulk of people in the database have committed no crimes. A Government Accountability Office report last year faulted the FBI for being lax about privacy and the accuracy of photos in its database. False positives have been known to ruin people's lives.

The most accurate algorithms submitted to the government for the contest are eligible to split a pot of $50,000, according to the contest rules.

Developers must submit precompiled software, and the software will be run on sequestered images.