A method of correcting the pointer reading of deflection pointer instrument

A method of correcting the pointer reading of a deflection pointer instrument is put forward, which realized the correction of the deflection circular pointer meter reading in the substation. Firstly, digital image processing technology is used to preprocess the instrument image. Secondly, the five point method is used to fit the ellipse, locate the dial area and the center of the dial, and the distance between the center of the dial and the center of the pointer is calculated. Finally, according to the obtained distance to correct the pointer readings, the final correct reading of the pointer is output. The experimental results show that the algorithm can realize the correction of reading. The algorithm has the characteristics of simple model, fast running speed and high accuracy.