Abstract: This paper presents a pencil-sketching method based on image for the purpose of simulating the style of artists.Firstly，the color image is sharpen by Unsharp Mask（USM） to extract detail information，and color scaling is used to strength contrast degree.Secondly，stroke direction is generated by the method of vector field.Finally results of the pencil-drawing are gained by the line integral convolution（LIC） algorithm.The white noises are replaced by result image of USM for getting better effects of pencil texture.Results show that this approach can render images to an artistic style which is suitable for pencil sketching and personalized photo.

Key words: pencil-sketching, line integral convolution, Unsharp Mask（USM） technique, non-photorealistic rendering

摘要： 通过分析铅笔画的艺术特点，提出一种基于图像的铅笔画仿真方法。首先对用户输入的图像进行Unsharp Mask（USM）锐化提取细节信息，并进行颜色放大处理以增强对比度，然后采用基于点的向量场技术生成笔画方向，最后应用线积分卷积（LIC）得到具有素描风格的结果图像。为了更好地模拟铅笔纹理，改进了传统的纹理生成方法，提出将锐化后的结果图像代替白噪声图作为LIC的输入。实验结果表明，该方法的生成效果更接近于手绘风格，且无需用户交互，适合于动画制作等很多领域的应用。

关键词: 铅笔画, 线积分卷积, USM锐化, 非真实感图形学