The result extraction of irregular dial instrument based on the image

Irregular dial instruments, such as SF6, are widely used in industry environment. The results of these instruments are usually obtained by artificial. In order to make the result's acquisition and record automatically, this paper proposed an irregular dial instrument's result extraction method based on the image. This method gets the major features of dial instruments through ransac method and least square ellipse fitting. The pointer point, reference point and center point of instruments are extracted and used for the calculation of instruments' results. The errors can be kept at 5% with proposed method contrast with the result by artificial. The experimental results show that the result of irregular dial instrument can be effectively got by the proposed method. The proposed method has a reference for the other dial instruments.