Robust Low Complexity Corner Detector
Corner feature point detection with both the high-speed and high-quality is still very demanding for many real-time computer vision applications. The Harris and Kanade-Lucas-Tomasi (KLT) are widely adopted good quality corner feature point detection algorithms due to their invariance to rotation, noise, illumination, and limited view point change. Although they are widely adopted corner feature point detectors, their applications are rather limited because of their inability to achieve real-time performance due to their high complexity. In this paper, we redesigned Harris and KLT algorithms to reduce their complexity in each stage of the algorithm: Gaussian derivative, cornerness response, and non-maximum suppression (NMS). The complexity of the Gaussian derivative and cornerness stage is reduced by using an integral image. In NMS stage, we replaced a highly complex sorting and NMS by the efficient NMS followed by sorting the result. The detected feature points are further interpolated for sub-pixel accuracy of the feature point location. Our experimental results on publicly available evaluation data-sets for the feature point detectors show that our low complexity corner detector is both very fast and similar in feature point detection quality compared to the original algorithm. We achieve a complexity reduction by a factor of 9.8 and attain 50 f/s processing speed for images of size 640×480 on a commodity central processing unit with 2.53 GHz and 3 GB random access memory.