关键词: 数字半调, 图像值质量评价, 图像处理

Abstract: Halftoning is the rendition of continuous-tone pictures on displays，paper or other media that are capable of producing only two levels.The technology has widely applied to typography，printing technology，compression memory of digital image and etc.A review of digital halftoning techniques which are base techniques of image processing is presented.The classical methods and recent advance of digital halftoning are introduced.Several image quality assessment methods are used to evaluate the digital halftoning techniques.Then，the trend of the digital halftoning technology development is described.

Key words: digital halftoning, image quality assessment, image processing