On the bases of the study on defective fiber ends

this paper proposes an improved method for obtaining the geometric parameters

which is based on gray-scale image threshold segmentation and elliptic boundary point selection and fitting

and extracting the edge point of the defective fiber by using the feature that the qualified fiber cladding and core edges have the same concentric circles.This feature can effectively remove the interference point.Compared with the two commonly used methods that are based on grayscale threshold segmentation and feature data point collection and on Canny operator edge detection and elliptic fitting respectively

this method figure out the geometric parameters of defective fiber ends more accurately.