Faster and better: a machine learning approach to corner detection

TL;DR

This paper introduces a machine learning-based corner detector that is faster and more repeatable than existing methods, capable of processing live video at real-time speeds with high accuracy.

Contribution

It presents a new heuristic and a machine learning approach for corner detection, optimizing for speed and repeatability, and provides a comprehensive comparison with existing detectors.

Findings

The new detector processes live PAL video using less than 5% of processing time.

It significantly outperforms existing detectors in repeatability on 3D scene tests.

Machine learning enhances both speed and quality of corner detection.

Abstract

The repeatability and efficiency of a corner detector determines how likely it is to be useful in a real-world application. The repeatability is importand because the same scene viewed from different positions should yield features which correspond to the same real-world 3D locations [Schmid et al 2000]. The efficiency is important because this determines whether the detector combined with further processing can operate at frame rate. Three advances are described in this paper. First, we present a new heuristic for feature detection, and using machine learning we derive a feature detector from this which can fully process live PAL video using less than 5% of the available processing time. By comparison, most other detectors cannot even operate at frame rate (Harris detector 115%, SIFT 195%). Second, we generalize the detector, allowing it to be optimized for repeatability, with little loss of efficiency. Third, we carry out a rigorous comparison of corner detectors based on the above repeatability criterion applied to 3D scenes. We show that despite being principally constructed for speed, on these stringent tests, our heuristic detector significantly outperforms existing feature detectors. Finally, the comparison demonstrates that using machine learning produces significant improvements in repeatability, yielding a detector that is both very fast and very high quality.