一种光学测量中椭圆边缘精确提取算法

提出了一种椭圆边缘精确提取算法。对图像灰度分布函数按二次泰勒展开式展开，利用高斯核函数和图像卷积的方式进行微分求导，在过零点附近求取二阶导数绝对值的极小值点，然后，通过计算Hessian矩阵得到该边缘点的法向方向，在法向方向进行多项式曲线拟合和直线拟合得到子像素边缘点。实验结果表明，算法子像素边缘提取具有较好的精度，在光学测量椭圆形标识检测中有参考价值。

Algorithm for Accurately Extricating Ellipse Detail Edge in Optical Measurement

An algorithm for accurately extricating ellipse detail edge in optical measurement was proposed. Image gray distribution function was transformed to second Taylor expansion. In order to analyze relative zero-crossing point, image derivative was calculated by the convolution of Gaussian kernel and image gray function. Then, normal direction of edge points was calculated by using Hessian matrix. To obtain sub-pixel precise ellipse edge, fitting methods based on polynomial curve and line were presented and applied in normal direction by this algorithm. The experimental results demonstrate that the proposed algorithm is high precise and has better reference value for ellipse edge extrication in optical measurement.