357 research outputs found
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High-speed multi-dimensional relative navigation for uncooperative space objects
This work proposes a high-speed Light Detection and Ranging (LIDAR) based navigation architecture that is appropriate for uncooperative relative space navigation applications. In contrast to current solutions that exploit 3D LIDAR data, our architecture transforms the odometry problem from the 3D space into multiple 2.5D ones and completes the odometry problem by utilizing a recursive filtering scheme. Trials evaluate several current state-of-the-art 2D keypoint detection and local feature description methods as well as recursive filtering techniques on a number of simulated but credible scenarios that involve a satellite model developed by Thales Alenia Space (France). Most appealing performance is attained by the 2D keypoint detector Good Features to Track (GFFT) combined with the feature descriptor KAZE, that are further combined with either the H∞ or the Kalman recursive filter. Experimental results demonstrate that compared to current algorithms, the GFTT/KAZE combination is highly appealing affording one order of magnitude more accurate odometry and a very low processing burden, which depending on the competitor method, may exceed one order of magnitude faster computation
Comparing Feature Detectors: A bias in the repeatability criteria, and how to correct it
Most computer vision application rely on algorithms finding local
correspondences between different images. These algorithms detect and compare
stable local invariant descriptors centered at scale-invariant keypoints.
Because of the importance of the problem, new keypoint detectors and
descriptors are constantly being proposed, each one claiming to perform better
(or to be complementary) to the preceding ones. This raises the question of a
fair comparison between very diverse methods. This evaluation has been mainly
based on a repeatability criterion of the keypoints under a series of image
perturbations (blur, illumination, noise, rotations, homotheties, homographies,
etc). In this paper, we argue that the classic repeatability criterion is
biased towards algorithms producing redundant overlapped detections. To
compensate this bias, we propose a variant of the repeatability rate taking
into account the descriptors overlap. We apply this variant to revisit the
popular benchmark by Mikolajczyk et al., on classic and new feature detectors.
Experimental evidence shows that the hierarchy of these feature detectors is
severely disrupted by the amended comparator.Comment: Fixed typo in affiliation
Performance and analysis of feature tracking approaches in laser speckle instrumentation
This paper investigates the application of feature tracking algorithms as an alternative data processing method for laser speckle instrumentation. The approach is capable of determining both the speckle pattern translation and rotation and can therefore be used to detect the in-plane rotation and translation of an object simultaneously. A performance assessment of widely used feature detection and matching algorithms from the computer vision field, for both translation and rotation measurements from laser speckle patterns, is presented. The accuracy of translation measurements using the feature tracking approach was found to be similar to that of correlation-based processing with accuracies of 0.025–0.04 pixels and a typical precision of 0.02–0.09 pixels depending upon the method and image size used. The performance for in-plane rotation measurements are also presented with rotation measurement accuracies of <0.01 found to be achievable over an angle range of ±10 and of <0.1 over a range of ±25 ±25 , with a typical precision between 0.02 and 0.08 depending upon method and image size. The measurement range is found to be limited by the failure to match sufficient speckles at larger rotation angles. An analysis of each stage of the process was conducted to identify the most suitable approaches for use with laser speckle images and areas requiring further improvement. A quantitative approach to assessing different feature tracking methods is described, and reference data sets of experimentally translated and rotated speckle patterns from a range of surface finishes and surface roughness are presented. As a result, three areas that lead to the failure of the matching process are identified as areas for future investigation: the inability to detect the same features in partially decorrelated images leading to unmatchable features, the variance of computed feature orientation between frames leading to different descriptors being calculated for the same feature, and the failure of the matching processes due to the inability to discriminate between different features in speckle images
Speckle tracking approaches in speckle sensing
This paper reports some initial investigations into the application of feature tracking algorithms as an alternative data processing method for speckle correlation sensors capable of determining both the speckle pattern translation and rotation. The accuracy of translation measurements using the feature tracking approach was found to be similar to that of correlation based processing with accuracies of < 0.04 pixels. Rotation measurement accuracies of< 0.05 ◦ are found to be achievable over angle range ±20 ◦ , limited by the failure to match speckles at larger rotation angles
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