It’s important to extract target points center from image in computer vision quickly and accurately. The center extract with the raw gradient information in the neighborhood of the target points boundary to get the parameters of the ellipse, avoids the intermediate stage of precisely extracting individual edge points. Moreover, under the dual space representation, the ellipse parameter can easily be calculated from the dual conic with the qualification of the ellipse, and the ellipse center will be got at the same time. Then, the RANSAC algorithm is used to match the pair of corresponding points between the calibration image and the calibration plate. The experiment and application result shows that the method is efficiently.
The Research of Ellipse Parameter Fitting Algorithm of Ultrasonic Imaging Logging in the Casing Hole