分区间曲线拟合的干涉条纹中心点提取方法

Interference Fringe Center Point Extraction Method Based on Interval Curve Fitting

提出一种分区间曲线拟合方法来准确获取干涉条纹的中心点。该方法根据干涉条纹图灰度值分布规律,首先对干涉条纹R值图进行高斯低通滤波,在保留原始条纹信息的基础上去除噪声;然后,在滤波后的图像中选取法线方向的一列像素值,得出灰度分布曲线;最后,截取邻近峰值的一段图像,对增、减两个区间进行分段曲线拟合,求得两段曲线拟合函数的交点即为干涉条纹中心。实验证明,该方法具有较好的曲线拟合效果,其速度相对于Steger算法提高了近10倍。该算法能有效地根据干涉条纹灰度分布规律得到干涉条纹中心点,具有运算简便、精度高、抗干扰的特点。

To accurately obtain the center point of interference fringes,a method based on interval curve fitting was established.According to the gray value distribution of the interference fringe pattern,we first obtain the R value graph of the interference fringe and perform Gaussian low-pass filtering;then,we remove various noises while retaining the original fringe information.Thereafter,we consider the filtered image as a list of pixel values in the normal direction to obtain a gray distribution curve.Finally,we intercept the image near the peak to perform segmental curve fitting in the increasing interval and the decreasing interval and obtain the intersection point of the two curve fitting functions,which is the center point of the interference fringe.Experimental results show satisfactory curve fitting effect.Compared with the Steger algorithm,the speed of the proposed method is increased nearly ten times.The proposed method can be used to effectively obtain the center point of interference fringes according to the gray distribution law of interference fringes with a simple operation,high precision,and antiinterference characteristics.