Mo Xiaofei, Ding Youdong. Pencil sketch generation with shape features[J]. Journal of Image and Graphics, 2013, 18(2): 219-224. DOI: 10.11834/jig.20130214.
which represents objects by single color lines. The artists represent light and shading
while depicting shape features through observing the structure of the objects. In this paper
we present a non-photorealistic rendering technique that automatically generates a pencil sketch painting with shape features. We first use the bilateral filter to remove the noise. The vector field is calculated from the luminance image. We then develop a method for constructing a smooth vector field
which preserves shape features of the original image. Finally
line integral convolution and enhancing the contrast of light and shadow are used to generate the texture of pencil sketch. The experimental results show the effectiveness of this method in depicting an illusion of depth and producing the contrast of light and shadow.