计算机工程与应用 ›› 2011, Vol. 47 ›› Issue (9): 167-170.

• 图形、图像、模式识别 • 上一篇    下一篇

静态ternary逼近细分格式的连续性分析和构造

胡玫瑰,郑红婵,许 婷,徐 丰   

  1. 西北工业大学 理学院 应用数学系,西安 710129
  • 收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:2011-03-21 发布日期:2011-03-21

Continuity analysis and construction of ternary stationary approximating subdivision schemes

HU Meigui,ZHENG Hongchan,XU Ting,XU Feng   

  1. Department of Applied Mathematics,School of Science,Northwestern Polytechnical University,Xi’an 710129,China
  • Received:1900-01-01 Revised:1900-01-01 Online:2011-03-21 Published:2011-03-21

摘要:

提出了一般的三点三重、四点三重逼近细分格式,利用稳定细分格式Ck连续的充要条件,分析了细分法各阶连续时参数的取值范围。利用提出的一般细分法,可以造型光滑逼近曲线;当某些细分参数取特殊值时,还可以用来造型插值曲线。为便于应用,还对Hassan的3点ternary逼近细分法进行了改进,使其带有一个全局张力参数,通过它更易控制曲线的形状。在全局张力参数的一定范围内可以生成C1,C2连续的极限曲线。

关键词: 细分, 逼近格式, mask, 一致收敛性, 连续性分析

Abstract: Using the necessary and sufficient conditions for Ck-continuity of stationary subdivision schemes,the ranges of free parameter are analyzed for Ck-continuity of general arity-3 approximating 3-point scheme and arity-3 approximating 4-point subdivision scheme.Using this paper’s methods,smooth approximating curve can be generated;when some parameters take particular values,smooth interpolating curve can also be generated.In addition,in order to use easily,Hassan’s methods are improved by introducing a global tension parameter,which makes it much easier to control the shape of the curve.The new methods can be used to generate a family of C1,C2 limit curves in certain range of global tension parameter.

Key words: subdivision, approximating scheme, mask, convergence, continuity analysis