In view of the high precision of the Zernike moment subpixel location algorithm, but the algorithm has a long operation time, an improved Zernike moment subpixel location method based on Sobel is proposed. The algorithm detects the initial location of the sheath and the edge of the insulation material by Sobel, and reduces the computation range of the Zernike moments, so that the computation time is shortened and the speed is increased when the accuracy is basically unchanged.The accuracy of the algorithm is improved by reducing the width of the contour pixel on the single pixel by estimating the mean value of the normal distribution of the edge points.The superiority of the algorithm is verified by comparing the accuracy and speed of the improved Sobel-Zernike moment method, the common Zernike moment method and the improved interpolation method.
