San Francisco: Facebook on Wednesday said that it has bought facial recognition start-up FacioMetrics, potentially using the technology for photo or video effects to better challenge rival Snapchat. “How people share and communicate is changing and things like masks and other effects allow people to express themselves in fun and creative ways,” a Facebook spokesperson said in an email reply to an AFP inquiry. Silicon Valley-based Facebook did not disclose financial terms of the deal to buy FacioMetrics, which was spun out of Carnegie Mellon University in Pennsylvania.