A rapid algorithm for extracting circular marked point
Xie Ze-xia · Optical Technique · 2013
In order to identify and position the center of the round marked points rapidity and high-accurately,a method is proposed.When the camera is imaging,because the round marked points are similar to the ellipse after perspective projection transformation,the center of the elliptic is obtained through elliptic fitting.The coarse edge points are got,then the sub-pixel edge points are got using the characteristic of Gaussian distribution.The edge points are optimized and fitted for ellipse by use of the method of least squares.The more accurate center coordinates are obtained.Experiments show that the time of the algorithm is about 0.005sand the accuracy of the ellipse's circle is about 0.05pixel.It is convenient for practical application.