一种快速检测圆的抗干扰变形模板方法

A Fast Interference-Resistent Deformable Template Method for Detecting the Circle

提出了一种新的参量式变形模板方法 ,用于检测带有缺陷和噪声的圆。根据圆的几何形状特性和梯度信息定义了模板的能量函数。然后通过动态调整模板的参量使能量函数和图像进行交互以把能量函数最大化。根据能量函数的定义 ,在其取得最大值时的参量即为所检测圆的位置参量。为了提高匹配运算速度 ,先求出被检测圆的圆心和半径的估计值 ,然后给出缩小了的搜索区域。在此搜索区域内采用贪婪优化的算法得到最终检测结果。实验结果表明算法可以在圆有较大缺陷和噪声的情况下 ,定位精度在 1个像素以内 ,速度在 0 .5s左右 ;有很好的抗干扰和抗噪声能力 ,并有较快的运算速度。

A new method for detecting circle with defects a nd noise using parametric deformable template is proposed. An energy function of the deformable template is defined according to geometric characteristics of th e circle and gradient information of the image. The template then interacts dyna mically with the image and energy function by altering its parameter values to m aximize the energy function. The final parameter values (maximum) can give the l ocation of the circle according to definition of the energy function. In order t o raise the matching speed, a decreased search region is given by estimating val ues of the radius and the center of the circle. Then the energy function is opti mized using greedy method in the search region. Experimental results show that t he algorithm can localize the circle within a pixel and about 0.5 s; even the ci rcle has defects and noise. This method has good resistence to interference and noise, and fast operation.