high def
noun [ U ] uk/ˌhaɪ ˈdef/ us/ˌhaɪ ˈdef/
高清晰度（high definition的缩写）
abbreviation for high definition: a system for showing very clear pictures on a television or computer screen or for producing very clear sound
With high def, you can recognize faces in the crowd. 使用高清晰度技术，你可以从人群中识别人脸。