Abstract: Non-photorcalistic rendering is a branch of computer graphics,which is committed to generate some art style works. Currently,non-photorealistic rendering technology (NPR) has been able to successfully simulate the oil paintings, watercolors, cartoons, pencil and some other styles, and has been widely used in many areas. Pencil sketch is the basis of art modeling. Since usually simple and smooth, pencil works arc deeply loved by people. However, it is not easy for every person to master the skills of pencil drawing. Imag}based pencil rendering technique is an important part of NPR, and is more and more concerned by researchers. 13ut related technologies arc still immature, and can' t meet the needs of practical applications.

Key words: Non-photorealistic rendering,Image-based rendering,Pencil drawing