In this paper, we describe a new approach for estimating 3D pose of a human face from a monocular image. We assume that the shape of a face can be approximated by an ellipse and the ratio of the major to minor axis of the ellipse is given. We rst detect a face ellipse and then estimate the face pose. Compared with the existing feature-based approaches for face pose estimation, our approach is m...

We describe the use of the Kalman filter to find optimal fits to short sections of ellipse data and to predict confidence envelopes in order to facilitate search for further ellipse data. The extended Kalman filter in its usual form is shown not to reduce the well known bias to high curvature involved in least squares ellipse fitting. This problem is overcome by developing a linear bias correct...

Quantization-free parameter space reduction in ellipse detection Kuang Chung Chen Ellipse modeling and detection is an important task in many computer vision and pattern recognition applications. In this thesis, four Hough-based transform algorithms have been carefully selected, studied and analyzed. These techniques include the Standard Hough Transform, Probabilistic Hough Transform, Randomize...

3 Results 5 3.1 Numerical phantom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.2 Projection acquisition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3.3 Estimation of ellipse parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3.4 Usage...

Measuring ellipticity is an important area of computer vision systems. Most existing ellipticity measures are area based and cannot be easily applied to point sets such as extracted edges from real world images. We are interested in ellipse fitting and ellipticity measures which rely exclusively on shape boundary points which are practical in computer vision. They should also be calculated very...

We give, in the case of ellipse, a simple connection between the spectrum of the Kerzman–Stein operator and the eccentricity of the ellipse.

In this paper, the idea of Mid-point ellipse drawing algorithm on a hexagonal grid is proposed. The performance of the proposed algorithm is compared to that of the conventional ellipse drawing algorithm on a square grid. The qualitative and execution time analysis proves that the proposed algorithm performs better than the conventional ellipse drawing algorithm on a square grid.