关键词: 成像缺陷, 保偏光纤, 基于邻域自适应调整, 偏振轴, 应力区

Abstract: Aiming to address the challenge of accurately identifying the polarization axis in polarization-maintaining fiber images with imaging defects,such as abnormal local brightness and low contrast between the fiber end face and the stress region,a detection method for the polarization axis of imaging-defective fiber images based on neighborhood-adaptive adjustment was proposed.Initially,the method adjusted the anomalous pixel values of the fiber end face by constructing an adaptive global threshold.Subsequently,a dynamic local threshold was formulated to correct the pixel values in the transition zone between the fiber end face and the stress region.Finally,sub-pixel interpolation was employed to extract the contour of the segmented stress area,thereby achieving sub-pixel-level precise positioning of the stress area boundary and the polarization axis of the defective optical fiber image.Experimental results demonstrated that compared with the Canny-Otsu algorithm,Canny-MS-Scharr algorithm,Canny-EC algorithm and Canny-SFNI algorithm,the proposed method reduced the detection error in the stress region by over 80%,while maintaining the detection deviation of the polarization angle under Gaussian and salt-and-pepper noise influences within 0.3°.

Key words: imaging defect, polarization maintaining fiber, neighborhood-based adaptive adjustment, polarization axis, stress zone