共查询到16条相似文献,搜索用时 177 毫秒
1.
2.
针对在虚拟现实中重现物体的精确性问题,提出了采用自适应方法提取合适的特征点来插值B样条曲线的算法,实现了满足一定精度要求的数据点拟合以及控制点的反算.该算法首先通过曲率信息选取初始特征点作为型值点,然后应用线性约束能量最小化方法反算出控制点.由控制点和节点矢量拟合出B样条曲线,找出数据点与曲线偏差最大点,利用曲线复杂度指标自适应地添加新特征点,反复迭代直到满足要求的误差精度.该算法适用于逆向工程设计中重建物体和计算空间曲面控制点等问题. 相似文献
3.
基于B样条曲线及遗传算法求解TA/TA问题 总被引:3,自引:2,他引:1
主要讨论了水平面上空面导弹TA/TA(地形回避/威胁回避)问题。首先通过Dijkstra算法求出地形、威胁包络的最短及几个较短路径通道;用所求通道上的关键点作为三次B-样条曲线的顶点,近似拟合导弹飞行路线。以本文提出的最小距离法生成适应度函数,考虑导弹机动能力的约束,通过遗传算法来调整B-样条曲线的顶点,从而寻找出性能指标最优的可飞行样条曲线;根据所求出的最优样条曲线给出导弹航路点。通过大量的仿真实验,证明该方法是可行的,具有快速性并适应于大范围、复杂地形和威胁环境。 相似文献
4.
利用B样条实现基于等高线的三维地形图 总被引:2,自引:0,他引:2
利用B样条曲线将等高线光栅图矢量化。根据B样条曲线插值公式得到等高线与纵横网格线的交点;根据这些史点的三维坐标值,利用线形插值分别得到纵横网格交点的高程,其均值作为网格变点的最终高程;最后利用OpenGL中的NURBS曲面接口生成三维地形图。该方法输入工作量小.数据存储量少。模拟效果较好。 相似文献
5.
6.
插值在信号处理领域有着广泛的应用,人们提出了各种插值算法。B样条插值是一种插值性能很好的算法,而且存在高效实现算法,易于硬件实现。文中对3次B样条插值进行了详细分析,研究了3步滤波的插值算法。通过对3次B样条插值和3次样条插值仿真结果进行比较,确定了最终实现算法。最后,用Verilog代码实现了该插值算法,并且用X ilinx公司的Vertex-Ⅱpro 100芯片进行了测试。 相似文献
7.
三次均匀B样条插值曲线和曲面的矩阵形式 总被引:2,自引:0,他引:2
根据三次B样条曲线(CB)的矩阵形式灵活的特点、CB曲线的端点性质和插值曲线在连接点应满足的连续性条件,推导出CB插值(CBI)曲线的矩阵形式,并进一步推广,得到了双CBI曲面的矩阵形式.生成了平面和空间插值曲线、闭合插值曲线和插值面片.与传统方法进行了比较,结果表明,本文方法有较大的优越性和较好的实用价值. 相似文献
8.
引入B样条对头发及发型进行真实感建模与仿真.由悬臂梁模型生成初始数据点,经B样条曲线反算生成自然弯曲的关键头发;由周期性闭合B样条曲线反算生成头发簇的截面曲线;利用B样条的局部性质对关键头发和截面曲线进行形状调整;在关键头发和截面曲线的基础上运用蒙面算法生成头发簇.最后在头部模型上按区域生成头发簇并进行光照渲染完成整体发型设计与仿真.结果表明,该方法对头发的控制比较简单,可以获得各种发型. 相似文献
9.
10.
介绍了采用三次样条曲线插值方法对称重仪表的非线性误差进行修正的方法,该修正方法对于线性误差较大的传感器有很好的补偿效果,在某些测量精度较高的场合采用三次样条曲线插值可以获得比流行的多段折线线性补偿方法更高的精度。通过对一款5位半仪表采用三种误差处理方法比较,验证了三次样条曲线插值误差补偿方法对传感器误差的补偿效果。该方法对于其他的数据采集系统精度提升有一定的借鉴意义。 相似文献
11.
针对不同地形点云数据采用不同的滤波和格网插值方法提取地面信息,得到了良好的滤波插值效果,为后续地表下沉盆地获取等工作提供了优质的基础数据。对于不同的点云数据,文中分别进行了针对性的处理。对地表平坦且植被稀少的点云数据,采取高程最低点采样并替代格网高程值的方法;对地物和植被杂乱的点云数据,采用基于先验高程信息滤波与Kriging格网插值相结合的方法;而对于地形起伏较大的点云数据则采用渐点加密TIN滤波与Kriging格网插值相结合的方法,最终得到高质量的基础数据并应用于工程实际。 相似文献
12.
This paper presents a new multiscale curvature-based shape representation technique with application to curve data compression using B-spline wavelets. The evolution of the curve is implemented in the B-spline scale-space, which enjoys a number of advantages over the classical Gaussian scale-space, for instance, the availability of fast algorithms. The B-spline wavelet transforms are used to efficiently estimate the multiscale curvature functions. Based on the curvature scale-space image, we introduce a coarse-to-fine matching algorithm which automatically detects the dominant points and uses them as knots for curve interpolation. 相似文献
13.
14.
A MAP framework for tag line detection in SPAMM data using Markov random fields on the B-spline solid 总被引:1,自引:0,他引:1
Magnetic resonance (MR) tagging is a technique for measuring heart deformations through creation of a stripe grid pattern on cardiac images. In this paper, we present a maximum a posteriori (MAP) framework for detecting tag lines using a Markov random field (MRF) defined on the lattice generated by three-dimensional (3-D) and four-dimensional (4-D) (3-D + t) uniform sampling of B-spline models. In the 3-D case, MAP estimation is cast for detecting present tag features in the current image given an initial solid from the previous frame (the initial undeformed solid is manually positioned by clicking on corner points of a cube). The method also allows the parameters of the solid model, including the number of knots and the spline order, to be adjusted within the same framework. Fitting can start with a solid with less knots and lower spline order and proceed to one with more knots and/or higher order so as to achieve more accuracy and/or higher order of smoothness. In the 4-D case, the initial model is considered to be the linear interpolation of a sequence of optimal solids obtained from 3-D tracking. The same framework proposed for the 3-D case can once again be applied to arrive at a 4-D B-spline model with a higher temporal order. 相似文献
15.
Affine-invariant B-spline moments for curve matching 总被引:6,自引:0,他引:6
The article deals with the problem of matching and recognizing planar curves that are modeled by B-splines, independently of possible affine transformations to which the original curve has been subjected (for example, rotation, translation, scaling, orthographic, and semiperspective projections), and possible occlusion. It presents a fast algorithm for estimating the B-spline control points that is robust to nonuniform sampling, noise, and local deformations. Curve matching is achieved by using a similarity measure based on the B-spline knot points introduced by Cohen et al. (1991). This method, however, can neither handle the affine transformation between the curves nor the occlusion. Solutions to these two problems are presented through the use of a new class of weighted B-spline curve moments that are well defined for both open and closed curves. The method has been applied to classifying affine-transformed aircraft silhouettes, and appears to perform well. 相似文献