A Fast Ellipse Detector Using Projective Invariant Pruning
This addresses the need for real-time ellipse detection in resource-limited hardware scenarios, representing an incremental improvement in speed and accuracy.
The paper tackles the problem of detecting ellipses in images for real-time applications like robot navigation and industrial diagnosis, where existing methods are too slow due to many fragment candidates. It presents a fast algorithm that uses a projective invariant to prune candidates, achieving 20%-50% faster runtime than state-of-the-art methods with comparable or higher precision on 650 images across three datasets.
Detecting elliptical objects from an image is a central task in robot navigation and industrial diagnosis where the detection time is always a critical issue. Existing methods are hardly applicable to these real-time scenarios of limited hardware resource due to the huge number of fragment candidates (edges or arcs) for fitting ellipse equations. In this paper, we present a fast algorithm detecting ellipses with high accuracy. The algorithm leverage a newly developed projective invariant to significantly prune the undesired candidates and to pick out elliptical ones. The invariant is able to reflect the intrinsic geometry of a planar curve, giving the value of -1 on any three collinear points and +1 for any six points on an ellipse. Thus, we apply the pruning and picking by simply comparing these binary values. Moreover, the calculation of the invariant only involves the determinant of a 3*3 matrix. Extensive experiments on three challenging data sets with 650 images demonstrate that our detector runs 20%-50% faster than the state-of-the-art algorithms with the comparable or higher precision.