基于小波描述子的叶片轮廓几何建模

Geometrically Modeling Leaf Outline Based on Wavelet Descriptors

利用植物动漫部件组装整株植物是植物生长单帧建模的一个既简单又有效的方法,但由于植物形态的复杂性,其数据结构一般采用长度不等的链表来存储形态数值,这不但给特征点位置的设计和存储带来困难,而且影响图形显示速度.为此提出一种利用小波描述子来刻画植物器官形态的方法.以植物叶片轮廓的建模为例,先构造出刻画叶片轮廓形态的形状函数;再用周期小波级数进行逼近,从而获得个数相同的小波级数系数,可用统一长度的数组结构来存储不同种类植物的叶片轮廓.针对3种不同植物叶片轮廓的建模实验结果表明,该方法能较好地保持叶片轮廓,具有建模速度快和图形显示多分辨率等优点,且可以推广到植物其他器官轮廓和骨架的建模.

Using cartoon components to assemble a whole plant is a simple and effective method for modeling single-frame plant growth.In view of the complexity of plant morphologies,linked lists with variable lengths are often adopted as leaves＇ data structure to store their morphological data.Such methods make it difficult to design and store positions of characteristic points and influence the displaying speed.A new method using wavelet descriptors to describe plant morphology is presented in this paper.Taking modeling leaf outlines as an example,shape functions of leaf outlines are firstly constructed.Then periodic wavelet series are used to approximate shape functions and identical-size wavelet series coefficients are obtained.Therefore,uniform-length arrays can be used to store different kinds of leaf outlines.The effectiveness of the proposed method is verified by modeling the outlines of three kinds of plant leaves.Experimental results indicate that the method can keep the origin outlines of different leaves very well with the virtues of fast modeling speed and multi-resolution display.Furthermore,it can also be used to model the outlines and skeletons of other plant organs.