A novel and simple ellipse detection method is proposed in this paper. First, Canny operator is carried on the gray image to get edge image. Second, all the edge segments are obtained from edge image and output gradients of edge segments for further analysis. According to gradient direction, the edge segments are split into primitive lines and arcs. Then elliptical arcs are extracted from the results of splitting and an efficient grouping strategy is proposed to group elliptical arcs coming from the same ellipse as candidate ellipse. Finally, least-square fitting method is implemented to estimate the parameters of these candidate ellipses. Experiment results show that the proposed method is robust to noise and fast for real-time implementation.