Improvement of Rational Tangent Screening Algorithm

摘要

Using standard grayscale image, based on threshold template method it obtained the screening threshold matrix of Photoshop. By Matlab programming method it defined Photoshop used rational tangent screening algorithm. Facing the core issue of rational tangent screening (approximation problem of traditional screening angle 15o) and other theory and technology issues in digital screening technology, it researched in different screening angles experiments by Matlab programming method. The main conclusion included 18.4o was not the best instead for traditional screening angle 15o and the best screening line-ratio of three main screening angles (0/18.4o/45o) was not the only, but it had more choices.