铅笔素描是以单色线条来表现物体的艺术。画家观察物体的形体结构,以线塑型表现物体明暗层次和形体特征。为了表现物体的立体感,提出一种利用形体特征的铅笔素描画生成方法。首先对图像进行双边滤波处理,去除图像微小细节;然后由亮度图像计算其向量场,根据物体的形体特征对向量进行平滑,使其符合原图像的形体特征;最后利用线积分卷积的方法生成铅笔素描纹理,调整明暗对比后得到铅笔素描的效果。实验结果表明,该方法能有效地绘制铅笔素描的立体感和明暗关系。

Pencil sketching is an art, 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.