Bilevel Rendition Method for Documents Including Grey-Scale and Bi-level Image with Real-time Contrast Detection

Abstract

There are some halftone processing methods which can represent both grey-scale images and bi-level images well. However, they reproduce low contrast images poorly. This report proposes a halftone processing method which can reproduce all image types, including low contrast character image, with high quality. This is performed by automatic contrast detection of these images, and by automatic processing parameter control.