虚拟牙齿矫正系统中牙齿分割方法研究

发布时间：2018-09-17 14:06

【摘要】：舌侧隐形牙齿矫正器具有安全、美观等特点,虚拟牙齿矫正系统为其广泛应用提供了技术支持。本文主要研究虚拟牙齿矫正系统中牙齿的分割方法及实现。本文简要介绍了牙颌三角网格模型的STL文件格式与三角网格分割方法,使用基于二次误差度量的方法简化模型,并保留了牙颌模型的细节信息。在简化后的模型上计算轮廓线能提高运行效率,使用轮廓线分割原始模型可以保留了原始的牙齿数据。本文详细分析了网格分割方法中的手动勾画分割方法与自动分割算法,首先实现了基于勾画的牙齿分割方法,用户通过鼠标在三维牙颌模型表面上勾画、标明轮廓线,该方法较为繁琐耗时。然后使用基于分水岭的牙齿分割方法计算牙齿轮廓线,实现了牙齿分割。针对分水岭算法存在过分割现象与锯齿状轮廓线的问题,本文提出基于三次B样条的牙齿分割方法,在分水岭算法计算牙齿轮廓线的基础上,使用三次B样条方法修改轮廓线。该方法实现了对轮廓线的局部调整与光顺,操作简单、方便。为进一步提高矫正系统的分牙效率,本文提出了基于交线曲率特征的牙齿分割方法。该方法通过建立自定义颌平面裁剪无意义的底座部分,在用户交互标记牙齿的基础上,使用多平面切割得到牙齿交线,计算交线上阈值内的离散曲率极值点坐标,通过连接极值点的方式生成牙齿轮廓线。本文提出了基于三次B样条的牙齿分割方法,实验表明该方法能稳定高效、精确地调整牙齿轮廓线。针对牙颌网格模型分割,本文提出了基于交线曲率的牙齿分割方法,实验表明该方法可以精确定位出满足系统要求的牙齿轮廓。
[Abstract]:The lingual invisible orthodontic device is safe and beautiful, and the virtual orthodontic system provides technical support for its wide application. This paper mainly studies the method and Realization of tooth segmentation in the virtual orthodontic system. The method of quadratic error measurement simplifies the model and retains the details of the tooth and jaw model. Calculating contour lines on the simplified model can improve the efficiency of operation, and using contour lines to segment the original model can retain the original tooth data. Firstly, a tooth segmentation method based on sketch is implemented. The user draws the outline on the surface of the three-dimensional dental model with the mouse. This method is tedious and time-consuming. In this paper, a method of tooth segmentation based on cubic B-spline is proposed. The contour is modified by cubic B-spline method on the basis of the tooth contour calculated by watershed algorithm. A method of tooth segmentation based on the curvature feature of intersection lines is proposed in this paper.The meaningless base of custom jaw plane clipping is established.On the basis of user's interactive labeling of teeth,the intersection lines of teeth are obtained by multi-plane cutting.The coordinates of discrete curvature extremum points in the threshold of intersection lines are calculated,and the tooth wheels are generated by connecting the extremum points. In this paper, a tooth profile segmentation method based on cubic B-spline is proposed. Experiments show that this method can adjust tooth profile stably, efficiently and accurately.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：R783.5

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