Viisage Technology Inc., Billerica, Mass., has upgraded its line of face-recognition products to include capabilities it acquired when it bought ZN Vision Technologies AG, a German pioneer in the technology.

The upgraded versions of FaceTools, FaceFinder and FacePass improve accuracy of criminal identification screening and other security-related applications, the company said.

FaceTools 3.0 is the company's software developers' kit; FaceFinder 2.5 matches surveillance feeds with watch lists and other databases; FacePass 4.1 is an access control program. According to Viisage, agencies within the Defense and State departments are using the new versions.