Research On Halftoning And Hybrid Screening Technology

Traditional digital screening, is divided into AM and FM screening technology.Because of the limitation of them, hybird screening is widely adopted. The improvement of hybrid screening not only rely on the technical merits of halftones, and different regional of selected is equally important. Against the screening limitation in the reaseach and practise at present, In this paper, based on the content of the AM / FM hybrid screening algorithm is proposed.Green noise characteristics of the AM / FM halftoning can modulate the dot size and density and the same times,it is a hybrid halftoning technology. The "cluster point" avoids excessive dot gain, and the random distribution eliminate the moire as well.Traditional hybrid screening is determined in different gray-scale, but can not reproduct a better image features and details. Based on the images of different characteristics, respectively, the gray-scale image is segmented with high-pass filter, the gradient method and so on; the traditional regional of AM , which switch to AM / FM halftoning to avoid moire and improve the visual effects of the image. Experiment also proved that hybrid screening have greater stability under the variational pressure in offset.