A Stylized Approach for Pencil Drawing from Photographs

Abstract

We present a stylized scheme that produces pencil drawings in a range of styles from an image. To produce controllable pencil drawing effects and remedy the problems of existing convolution‐based schemes, we develop a swing bilateral LIC (SBL) filter. Our first approach to express the styled pencil drawings is to control the directions of pencil strokes that depicts both shapes and smooth tone. Another approach is to produce colors of pencil drawings by sampling colors from real color pencils. The third approach is to mimic the artistic technique that increases the details of drawings in a progressive manner. We present drawings in several styles and compare some of them directly with illustrations taken from an artists' work.

SRNPD: Spatial rendering network for pencil drawing stylization

“…Wang and Hu designed an interactive system called “IdiotPencil” that enables users to design pencil drawings directly from the three‐dimensional polygonal model. Yang et al developed a swing bilateral LIC filter to control pencil drawing effects and remedy problems of existing convolution‐based schemes. Hata et al automatically converted an image into a pencil drawing with an accentuation effect that directs viewers' attention to important information.…”

“…Researchers have spent decades on achieving the more human hand‐drawn–like results from the natural image, but there is still a long way to go for getting a result that well matches the real pencil drawings' flexibility and precision, especially when the skill of artists' pencil drawing ability is highly developed. A good pencil drawing has to vividly exhibit the inner structure of a scene that cannot be achieved by common existing methods . In addition, the current pencil drawing of an artist usually looks real, which requires that a pencil drawing generation method has to generate a realistic pencil drawing result; however, the current pencil drawing stylization methods cannot realize it.…”

PencilArt: A Chromatic Penciling Style Generation Framework

“…Yang et al . [YKM12] developed a swing bilateral LIC (SBL) filter to express the styled pencil drawings. But LIC is unstable for highly textured or noisy regions, as the right convolution direction is hard to decide.…”

“…Yang et al . [YKM12] controlled the stroke direction by determining pencil stroke flow from the objects in the input images. Lu et al .…”

“…However, these methods have not adequately considered the three key factors all sidedly. For example, outline generation was ignored in [YMI04a, MJN05] and [YKM12]; unique tone features of chromatic pencil drawings were not considered in [LXJ12], which probably leads to inharmonious results or obvious artefacts.…”