A man passes the ticket gate through facial recognition payment system at Zijingshan subway station in Zhengzhou, central China's Henan Province, Sept. 27, 2019. A facial recognition payment system was put into use in the Line 1 and the first phase of Line 14 of Zhengzhou Subway on Friday. (Xinhua/Li Jianan)

A man passes the ticket gate through facial recognition payment system at Zijingshan subway station in Zhengzhou, central China's Henan Province, Sept. 27, 2019. A facial recognition payment system was put into use in the Line 1 and the first phase of Line 14 of Zhengzhou Subway on Friday. (Xinhua/Li Jianan)

Passengers are seen at Zijingshan subway station in Zhengzhou, central China's Henan Province, Sept. 27, 2019. A facial recognition payment system was put into use in the Line 1 and the first phase of Line 14 of Zhengzhou Subway on Friday. (Xinhua/Li Jianan)