计算机自动识别标志点的实验研究

To study automatic identification of landmarks with computer

目的 :实现计算机自动识别头影测量标志点。方法 :选择 17张头影测量X光片 ,通过扫描仪输入计算机内 ,作图像预处理、滤波去噪、边缘提取、细化处理、曲线拟合等得到理想边缘后 ,建立识别标志点的数学模型和算法获得 2 0个标志点的自动定位并测量有关的线距角度值 ;在同样的X光片上做两次手工描绘标志点并测量其线距角度。结果 :实现了计算机自动定位 2 0个标志点 ;将两次手工描绘标志点所形成的线距角度值做配对t检验 ,所有结果无统计学差异 (P >0 .0 5 ) ;将自动定位的标志点相连所获得的线距角度值与手工描绘标志点相连所获得的线距角度平均值做配对t检验 ,所有结果无统计学差异 (P >0 .0 5 )。结论 :计算机能够达到手工描绘标志点时的准确程度。

Objective:To realize computer automatic identification of landmarks.Methods:24 X-ray cephalometric radiographs were selected,input computer by scanner.The pictures were treated with computer by the methods(advance office cutting,strain wave going and making an uproar,edge drawing,thinning to punish,curve fitting).After getting the ideal edges,various kinds of mathematic models and algorithms were set up to obtain 20 points automatic localization,the relevant distances and angles formed by the landmarks were measured automatically,and the same works were done by hand twice on same X-ray radiographs.Results:20 of landmarks were identified automatically,the relevant distances and angles formed by the landmarks were not statistically different between by computer and by hand (P>0.05).Conclusion:The computer can reach the accurate degree while marking one by hand.