Expressive Image Sketching with Two-Layer Image Features

The paper presents a framework for automatically natural image sketching, motivated by imitating the human line drawing process. The algorithm consists of two steps: sketch extraction and sketch rendering, using the recent computer vision and graphics techniques. In the first step, we design a bottom-up filter bank (low-level features) to propose sketch strength, position and orientation, and then trace and complete sketch following Gestalt laws (middle-level cues). In the second step, each sketch is rendered using a sketch-stroke model, accounting for the length, smoothness, width, and profile strength. Experimental results demonstrate the proposed approach is able to generate expressive sketch paintings from natural images.