Generating Pen and Ink Illustrations from Gray-scale Images—Line and Stippling Drawing Style—

Abstract

Recently, in computer graphics, not only photo-realistic-rendering but also non-photo-realistic-rendering is researched briskly. In this paper, focusing on pen-and-ink illustration that is usually put in books or used for technical illustration, we propose a method for generating a pen-and-ink illustration from a given gray-scale image. There are two fundamental styles in pen-and-ink illustration: one is line drawing style that represents an illustration by lines, and the other is stipple drawing style that represents one by dots. If the size of a line or a dot depends on the resolution of display device, we have one serious problem; in low-resolution device, the generated illustration can be given an artifact, that is, artificial pattern caused by the connection of lines or dots. By the method proposed in this paper, such artifact can be reduced using smoothness-line, which is given the fluctuation by 1/f noise, and smoothness-dot.