REVIEW 4 major objections 3 minor 45 references
ORB-SLAM3AB: Augmenting ORB-SLAM3 to Counteract Bumps with Optical Flow Inter-frame Matching
T0 review · 4 major / 3 minor · reviewed 2026-08-12 · deepseek-v4-flash
Pith's one-line read Adding adaptive optical flow to ORB-SLAM3 keeps monocular SLAM accurate on bumpy roads, with lower ATE and RPE than visual and LiDAR baselines in self-collected tests.
desk verdict Sensible adaptive optical-flow patch for ORB-SLAM3 on bumpy roads, but the evaluation is too under-specified to back the accuracy claims. read the letter →
The pith
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
The reading
What carries the argument
The load-bearing mechanism is an adaptive optical-flow feature-point selection module integrated into ORB-SLAM3's inter-frame matching stage. It works by maintaining a budget of optical-flow points, initialized at half the number of ORB feature points, and doubling that budget whenever the current frame's matched-feature count is too low, then shrinking it again when matches are plentiful. This adaptive budget is what lets the system lean on optical flow precisely when bumps destroy descriptor matches while preserving feature-point precision on calmer stretches; the HOG-based rotation consistency check is the filter that keeps the added flow points from injecting wrong correspondences.
What would settle it
Re-run ORB-SLAM3AB and ORB-SLAM3 on the same bumpy sequences with trajectories measured by a surveyed RTK-GNSS/INS reference, and recompute ATE and RPE; if the advantage shrinks or reverses, the central robustness claim fails. A second check is to run both systems on a smooth public benchmark: if ORB-SLAM3AB's error rises well above ORB-SLAM3's, the claimed adaptive trade-off is not holding.
Extended reading notes
Core claim
On the paper's own terms, the central claim is that prematurely lost inter-frame matches, not camera noise or map drift, are the main reason ORB-SLAM3 breaks on rough roads, and that an optical-flow supplement can recover those matches. ORB-SLAM3AB therefore inserts an adaptive optical-flow matching stage into ORB-SLAM3's frame-to-frame logic: keypoints are extracted from Gaussian-denoised grayscale frames, optical-flow points start at half the feature count, and whenever the number of successfully matched ORB features in the current frame is judged insufficient, the optical-flow point budget is doubled. A rotation-consistency check based on Histogram of Oriented Gradients then discards mismatched pairs. The reported consequence is that the system completes trajectories that ORB-SLAM3 and DSO fail on, and it produces the lowest ATE and RPE among all compared methods on the tested bumpy sequences.
Load-bearing premise
The load-bearing assumption is that the self-collected sequences have accurate ground-truth trajectories, yet the paper never states how that ground truth was produced; the paper also concedes in its reflection that the method may lose precision on smooth roads and still fails under extremely rapid shake.
Editorial extensions
If this is right
- Monocular visual SLAM can remain functional on speed-bump and bumpy-road routes without an IMU, LiDAR, or other added sensor.
- The adaptive optical-flow budget is a small, local change to ORB-SLAM3, so the same idea should transfer to other ORB-based visual SLAM pipelines.
- On short bumpy routes the reported results suggest a pure visual system can beat LiDAR-only odometry in trajectory error, not just match it.
- The paper's self-collected dataset, with day/night and snow variants, gives future work a testbed for bumpy-road SLAM, assuming it is released.
- A direct corollary is that vibration robustness and pose precision are traded through a single tunable counter, so future systems can adjust how aggressively they switch to optical flow.
Reading between the lines
- A natural extension is to trigger the optical-flow budget from a measured vibration signal, such as IMU readings or the spread of frame-to-frame homographies, instead of waiting for matched-feature counts to drop; that would let the system react before the first bump frames are lost.
- The same adaptive matching idea could be carried into stereo or RGB-D versions, where depth data could veto bad optical-flow correspondences during sharp shakes.
- The paper's own reflection concedes that adding optical flow may reduce precision on smooth roads and that extremely rapid shake still defeats the system; both are testable boundary conditions for any follow-up.
- If the dataset's ground-truth trajectories and calibration files are published, the numeric comparisons can be re-run independently; until then the ATE/RPE advantages are tied to the authors' evaluation setup.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper proposes ORB-SLAM3AB, an extension of monocular ORB-SLAM3 that augments ORB feature-point matching with optical-flow inter-frame matching and adaptively increases the number of optical-flow points when the matched feature count is low. The authors argue that this combination counters tracking loss during bumps on rugged roads. The method is evaluated on four self-collected sequences covering low- and high-speed, sunny and snowy, day and night conditions, and compared against ORB-SLAM3, DSO, Livox-SLAM, and CT-ICP using ATE and RPE. The paper claims superior robustness and accuracy on rugged road surfaces.
Significance. If the empirical claims are reproducible, the core idea is practically valuable: it is a lightweight modification to an established open-source SLAM system, requires no additional sensors, and targets a realistic failure mode (inter-frame tracking loss under vibration). The paper also contributes a self-collected multi-sensor dataset for bumpy-road scenarios and benchmarks against both visual and LiDAR SLAM baselines. The authors are candid about limitations, explicitly noting in Section V that optical flow may reduce precision on smooth roads and in Section VI that extremely rapid shake remains unsolved. However, the current significance is conditional: the evaluation protocol is under-specified to the point that none of the ATE/RPE numbers can be independently verified, and the evidence base of four sequences with hand-tuned parameters is thin.
major comments (4)
- [Section IV (Evaluation), Table I] The ground-truth reference for ATE and RPE is never specified. The text states only that 'the results were compared against ground truth,' without naming the sensor, algorithm, or post-processing used to obtain ground-truth trajectories, and without describing camera-LiDAR synchronization and calibration. This is load-bearing because every empirical conclusion in the paper derives from Table I; if the reference is itself a LiDAR SLAM output or an unvalidated map, the reported ranking could reflect the reference's error modes rather than the algorithms' true accuracy.
- [Section IV (Evaluation), Table I] The alignment procedure for trajectory evaluation is unspecified. Monocular trajectories are scale-ambiguous and must be aligned with a similarity (Sim(3)) transform before computing ATE/RPE, whereas LiDAR-based trajectories should be aligned with a rigid transform; the paper does not state which alignment was used for each system. Without this information, cross-system comparisons between monocular visual SLAM and LiDAR SLAM are not interpretable, and the ATE/RPE values in Table I cannot be reproduced.
- [Section II-A (System Overview) and Section IV (Evaluation)] The adaptive matching mechanism is not defined with fixed, reproducible parameters. The text says the initial optical-flow point count is half the number of feature points and is 'dynamically doubled' when matched features are insufficient, but the match-count threshold, the doubling factor, and any upper bounds are not specified; the paper even advises that 'the specific values of these parameters should be adjusted according to the actual conditions.' Because the parameters were evidently tuned on the same sequences used for evaluation, the reported improvements may reflect overfitting, and no sensitivity analysis or ablation is provided to show that the gains are robust to parameter choices.
- [Section IV (Evaluation), Table I] The experimental evidence is too thin to support the central claim. Only four sequences are reported, with no repeated runs, error bars, or statistical tests. On the low-speed-bumpy-sunny-night sequence, ORB-SLAM3AB achieves ATE 0.038 versus ORB-SLAM3's 0.039, which is a negligible improvement and could easily be within run-to-run variation. Additionally, the failure of ORB-SLAM3 and DSO on some sequences is marked only with 'x'; the failure mechanisms and the ground-truth conditions for those sequences are not discussed, leaving the successful completion by ORB-SLAM3AB as an unexplained single observation.
minor comments (3)
- [Section II-A (Rotation Consistency Check)] The description of the rotation consistency check is unclear: it says rotation angles are analyzed using a 'Histogram of Oriented Gradients (HOG) method,' but HOG is normally a gradient-descriptor technique, not a histogram of feature-point rotation angles; please clarify the actual procedure.
- [Section III (Data Collection)] The sensor specifications are missing: camera model and resolution, LiDAR model, frame rate, synchronization method, and calibration details are not reported, which makes the self-collected dataset unusable by other researchers and impedes reproducibility.
- [Author affiliations and references] There are small presentation issues: 'Xi,an' should be 'Xi'an'; reference [21] is listed as 'R 2 live' but the text and the cited title refer to R3LIVE; and the claim in the introduction that 'only a few, such as ORB-SLAM, support high-precision monocular camera SLAM' is vague and should be substantiated or rephrased.
Circularity Check
No significant circularity: the adaptive optical-flow mechanism is an online heuristic, and the accuracy claim rests on empirical ATE/RPE comparisons rather than a derivation that reduces to its own inputs.
full rationale
The paper's claimed derivation chain is algorithmic rather than mathematical: ORB-SLAM3AB adds an adaptive optical-flow matching stage to ORB-SLAM3. The only candidate circularity is the evaluation being performed on the authors' self-collected dataset with parameters that 'should be adjusted according to the actual conditions' (Section II-A). This is a legitimate reproducibility concern, but it is not circularity under the enumerated patterns: there is no equation whose output is identical to its input, no fitted parameter that is renamed as a prediction, and no load-bearing self-citation or imported uniqueness theorem. The adaptive rule (start with half the feature count; double optical-flow points when the matched-feature count is insufficient) is stated as an online mechanism, and the reported ATE/RPE improvements are empirical outcomes that could in principle have gone the other way. The underspecified ground truth and lack of a held-out split are experimental-validity weaknesses, not instances of the paper's conclusions being equivalent to its premises. Accordingly, no circular step is identified.
Assumptions & free parameters
free parameters (3)
- Initial optical flow point count =
half the number of feature points
- Optical flow point doubling factor =
2x when match count insufficient
- Match count insufficiency threshold =
not specified
assumptions (3)
- standard math Brightness constancy assumption underlying optical flow
- domain assumption Bumpy roads primarily cause inter-frame feature matching loss that can be recovered by more flow points
- ad hoc to paper Monocular ORB-SLAM3 with modified matching remains accurate
Cite this review
Pith. "Pith review of ORB-SLAM3AB: Augmenting ORB-SLAM3 to Counteract Bumps with Optical Flow Inter-frame Matching." pith.science (2026). https://pith.science/paper/E47CFKEB
@misc{pith2026241118174,
author = {Pith},
title = {Pith review of: ORB-SLAM3AB: Augmenting ORB-SLAM3 to Counteract Bumps with Optical Flow Inter-frame Matching},
year = {2026},
howpublished = {\url{https://pith.science/paper/E47CFKEB}},
note = {Machine review of arXiv:2411.18174}
}
read the original abstract
This paper proposes an enhancement to the ORB-SLAM3 algorithm, tailored for applications on rugged road surfaces. Our improved algorithm adeptly combines feature point matching with optical flow methods, capitalizing on the high robustness of optical flow in complex terrains and the high precision of feature points on smooth surfaces. By refining the inter-frame matching logic of ORB-SLAM3, we have addressed the issue of frame matching loss on uneven roads. To prevent a decrease in accuracy, an adaptive matching mechanism has been incorporated, which increases the reliance on optical flow points during periods of high vibration, thereby effectively maintaining SLAM precision. Furthermore, due to the scarcity of multi-sensor datasets suitable for environments with bumpy roads or speed bumps, we have collected LiDAR and camera data from such settings. Our enhanced algorithm, ORB-SLAM3AB, was then benchmarked against several advanced open-source SLAM algorithms that rely solely on laser or visual data. Through the analysis of Absolute Trajectory Error (ATE) and Relative Pose Error (RPE) metrics, our results demonstrate that ORB-SLAM3AB achieves superior robustness and accuracy on rugged road surfaces.
Figures
Reference graph
Works this paper leans on
-
[1]
A. A. B. Pritsker, Introduction to Simulation and SLAM II . Halsted Press, 1984
work page 1984
-
[2]
A review of slam techniques and security in autonomous driving,
A. Singandhupe and H. M. La, “A review of slam techniques and security in autonomous driving,” in 2019 third IEEE international conference on robotic computing (IRC) . IEEE, 2019
work page 2019
-
[3]
C. Cadena et al., “Past, present, and future of simultaneous localization and mapping: Toward the robust-perception age,” IEEE Trans. Robot. , vol. 32, no. 6, pp. 1309–1332, Dec. 2016
work page 2016
-
[4]
The slam problem: a survey,
J. Aulinas, Y . Petillot, J. Salvi, and X. Llad ´o, “The slam problem: a survey,” Artificial Intelligence Research and Development, pp. 363–371, 2008
2008
-
[5]
A solution to the simultaneous localization and map build- ing (slam) problem,
M. G. Dissanayake, P. Newman, S. Clark, H. F. Durrant-Whyte, and M. Csorba, “A solution to the simultaneous localization and map build- ing (slam) problem,” IEEE Transactions on robotics and automation , vol. 17, no. 3, pp. 229–241, 2001
work page 2001
-
[6]
Lsd-slam: Large-scale direct monocular slam,
J. Engel, T. Sch ¨ops, and D. Cremers, “Lsd-slam: Large-scale direct monocular slam,” in European conference on computer vision. Springer, 2014, pp. 834–849
2014
-
[7]
A flexible and scalable slam system with full 3d motion estimation,
S. Kohlbrecher, O. V on Stryk, J. Meyer, and U. Klingauf, “A flexible and scalable slam system with full 3d motion estimation,” in 2011 IEEE international symposium on safety, security, and rescue robotics. IEEE, 2011, pp. 155–160
work page 2011
-
[8]
Visual slam: What are the current trends and what to expect?
A. Tourani, H. Bavle, J. L. Sanchez-Lopez, and H. V oos, “Visual slam: What are the current trends and what to expect?” Sensors, vol. 22, no. 23, p. 9297, Nov. 2022. [Online]. Available: http: //dx.doi.org/10.3390/s22239297
Show all 45 references
-
[9]
Review on lidar-based slam techniques,
L. Huang, “Review on lidar-based slam techniques,” in 2021 Interna- tional Conference on Signal Processing and Machine Learning (CONF- SPML). IEEE, 2021, pp. 163–168
2021
-
[10]
A review of slam techniques and security in autonomous driving,
A. Singandhupe and H. M. La, “A review of slam techniques and security in autonomous driving,” in 2019 third IEEE international conference on robotic computing (IRC) . IEEE, 2019, pp. 602–607
2019
-
[11]
A survey of state-of-the-art on visual slam,
I. A. Kazerouni, L. Fitzgerald, G. Dooly, and D. Toal, “A survey of state-of-the-art on visual slam,” Expert Systems with Applications , vol. 205, p. 117734, 2022
2022
-
[12]
A comprehensive survey of visual slam algorithms,
A. Macario Barros, M. Michel, Y . Moline, G. Corre, and F. Carrel, “A comprehensive survey of visual slam algorithms,” Robotics, vol. 11, no. 1, p. 24, 2022
2022
-
[13]
Openvslam: A versatile visual slam framework,
S. Sumikura, M. Shibuya, and K. Sakurada, “Openvslam: A versatile visual slam framework,” in Proceedings of the 27th ACM International Conference on Multimedia , 2019, pp. 2292–2295
2019
-
[14]
Visual slam: why filter?
H. Strasdat, J. M. Montiel, and A. J. Davison, “Visual slam: why filter?” Image and Vision Computing , vol. 30, no. 2, pp. 65–77, 2012
2012
-
[15]
An overview to visual odometry and visual slam: Applications to mobile robotics,
K. Yousif, A. Bab-Hadiashar, and R. Hoseinnezhad, “An overview to visual odometry and visual slam: Applications to mobile robotics,” Intelligent Industrial Systems , vol. 1, no. 4, pp. 289–311, 2015
2015
-
[16]
A review of visual-lidar fusion based simultaneous localization and mapping,
C. Debeunne and D. Vivet, “A review of visual-lidar fusion based simultaneous localization and mapping,” Sensors, vol. 20, no. 7, p. 2068, 2020
2020
-
[17]
Lcdnet: Deep loop closure detection and point cloud registration for lidar slam,
D. Cattaneo, M. Vaghi, and A. Valada, “Lcdnet: Deep loop closure detection and point cloud registration for lidar slam,” IEEE Transactions on Robotics, vol. 38, no. 4, pp. 2074–2093, 2022
2022
-
[18]
Overlapnet: Loop closing for lidar-based slam,
X. Chen, T. L ¨abe, A. Milioto, T. R ¨ohling, O. Vysotska, A. Haag, J. Behley, and C. Stachniss, “Overlapnet: Loop closing for lidar-based slam,” arXiv preprint arXiv:2105.11344 , 2021
2021 arXiv
-
[19]
Elastic lidar fusion: Dense map-centric continuous-time slam,
C. Park, P. Moghadam, S. Kim, A. Elfes, C. Fookes, and S. Sridharan, “Elastic lidar fusion: Dense map-centric continuous-time slam,” in 2018 IEEE International Conference on Robotics and Automation (ICRA) . IEEE, 2018, pp. 1206–1213
2018
-
[20]
Loam livox: A fast, robust, high-precision lidar odometry and mapping package for lidars of small fov,
J. Lin and F. Zhang, “Loam livox: A fast, robust, high-precision lidar odometry and mapping package for lidars of small fov,” in 2020 IEEE International Conference on Robotics and Automation (ICRA) . IEEE, 2020
2020
-
[21]
R 2 live: A robust, real-time, lidar-inertial-visual tightly-coupled state estimator and mapping,
——, “R 2 live: A robust, real-time, lidar-inertial-visual tightly-coupled state estimator and mapping,” IEEE Robotics and Automation Letters , vol. 6, no. 4, pp. 7469–7476, 2021
2021
-
[22]
Ct-icp: Real-time elastic lidar odometry with loop closure,
P. Dellenbach et al., “Ct-icp: Real-time elastic lidar odometry with loop closure,” in 2022 International Conference on Robotics and Automation (ICRA). IEEE, 2022
2022
-
[23]
Orb-slam3: An accurate open-source li- brary for visual, visual–inertial, and multimap slam,
C. Campos and J. D. Tard ´os, “Orb-slam3: An accurate open-source li- brary for visual, visual–inertial, and multimap slam,” IEEE Transactions on Robotics, vol. 37, no. 6, pp. 1874–1890, 2021
2021
-
[24]
A general optimization-based framework for global pose estimation with multiple sensors,
T. Qin, S. Cao, J. Pan, and S. Shen, “A general optimization-based framework for global pose estimation with multiple sensors,” arXiv preprint arXiv:1901.03642, 2019
1901 arXiv
-
[25]
Visual slam algorithms: A survey from 2010 to 2016,
T. Taketomi, H. Uchiyama, and S. Ikeda, “Visual slam algorithms: A survey from 2010 to 2016,” IPSJ transactions on computer vision and applications, vol. 9, pp. 1–11, 2017
2010
-
[26]
Monoslam: Real-time single camera slam,
A. J. Davison, I. D. Reid, N. D. Molton, and O. Stasse, “Monoslam: Real-time single camera slam,” IEEE transactions on pattern analysis and machine intelligence , vol. 29, no. 6, pp. 1052–1067, 2007
2007
-
[27]
Orb-slam: a versatile and accurate monocular slam system,
R. Mur-Artal, J. M. M. Montiel, and J. D. Tardos, “Orb-slam: a versatile and accurate monocular slam system,” IEEE transactions on robotics , vol. 31, no. 5, pp. 1147–1163, 2015
2015
-
[28]
Orb-slam2: An open-source slam system for monocular, stereo, and rgb-d cameras,
R. Mur-Artal and J. D. Tard ´os, “Orb-slam2: An open-source slam system for monocular, stereo, and rgb-d cameras,” IEEE transactions on robotics, vol. 33, no. 5, pp. 1255–1262, 2017
2017
-
[29]
Direct sparse odometry,
J. Engel, V . Koltun, and D. Cremers, “Direct sparse odometry,” in arXiv:1607.02565, July 2016
2016 arXiv
-
[30]
Sl-slam: A robust visual-inertial slam based deep feature extraction and matching,
Z. Xiao and S. Li, “Sl-slam: A robust visual-inertial slam based deep feature extraction and matching,” arXiv preprint arXiv:2405.03413 , 2024
2024 arXiv
-
[31]
Orb-slam2s: A fast orb-slam2 system with sparse optical flow tracking,
Y . Diao, R. Cen, F. Xue, and X. Su, “Orb-slam2s: A fast orb-slam2 system with sparse optical flow tracking,” in 2021 13th International Conference on Advanced Computational Intelligence (ICACI) . IEEE, 2021, pp. 160–165
2021
-
[32]
A comprehensive imple- mentation of road surface classification for vehicle driving assistance: Dataset, models, and deployment,
T. Zhao, J. He, J. Lv, D. Min, and Y . Wei, “A comprehensive imple- mentation of road surface classification for vehicle driving assistance: Dataset, models, and deployment,” IEEE Transactions on Intelligent Transportation Systems, vol. 24, no. 8, pp. 8361–8370, 2023
2023
-
[33]
A road surface reconstruction dataset for autonomous driving,
T. Zhao, Y . Xie, M. Ding, L. Yang, M. Tomizuka, and Y . Wei, “A road surface reconstruction dataset for autonomous driving,” Scientific data, vol. 11, no. 1, p. 459, 2024
2024
-
[34]
The state of the art in flow visualisation: Feature extraction and tracking,
F. H. Post, B. Vrolijk, H. Hauser, R. S. Laramee, and H. Doleisch, “The state of the art in flow visualisation: Feature extraction and tracking,” in Computer Graphics Forum , vol. 22, no. 4. Wiley Online Library, 2003, pp. 775–792
2003
-
[35]
The computation of optical flow,
S. S. Beauchemin and J. L. Barron, “The computation of optical flow,” ACM computing surveys (CSUR) , vol. 27, no. 3, pp. 433–466, 1995
1995
-
[36]
Performance of optical flow techniques,
J. L. Barron, D. J. Fleet, S. S. Beauchemin, and T. Burkitt, “Performance of optical flow techniques,” in Proceedings 1992 IEEE Computer Society Conference on Computer Vision and Pattern Recognition . IEEE Computer Society, 1992, pp. 236–237
1992
-
[37]
Determining optical flow,
B. K. Horn and B. G. Schunck, “Determining optical flow,” Artificial intelligence, vol. 17, no. 1-3, pp. 185–203, 1981
1981
-
[38]
Secrets of optical flow estimation and their principles,
D. Sun, S. Roth, and M. J. Black, “Secrets of optical flow estimation and their principles,” in 2010 IEEE computer society conference on computer vision and pattern recognition . IEEE, 2010, pp. 2432–2439
2010
-
[39]
A comparative analysis of sift, surf, kaze, akaze, orb, and brisk,
S. A. K. Tareen and Z. Saleem, “A comparative analysis of sift, surf, kaze, akaze, orb, and brisk,” in 2018 International conference on computing, mathematics and engineering technologies (iCoMET) . IEEE, 2018, pp. 1–10
2018
-
[40]
When to use what feature? sift, surf, orb, or a-kaze features for monocular visual odometry,
H.-J. Chien, C.-C. Chuang, C.-Y . Chen, and R. Klette, “When to use what feature? sift, surf, orb, or a-kaze features for monocular visual odometry,” in 2016 International Conference on Image and Vision Computing New Zealand (IVCNZ) . IEEE, 2016, pp. 1–6
2016
-
[41]
Improved object recognition results using sift and orb feature detector,
S. Gupta, M. Kumar, and A. Garg, “Improved object recognition results using sift and orb feature detector,” Multimedia Tools and Applications, vol. 78, no. 23, pp. 34 157–34 171, 2019
2019
-
[42]
A tutorial on quantitative trajectory eval- uation for visual (-inertial) odometry,
Z. Zhang and D. Scaramuzza, “A tutorial on quantitative trajectory eval- uation for visual (-inertial) odometry,” in 2018 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) . IEEE, 2018, pp. 7244–7251
2018
-
[43]
Vision-aided absolute trajectory estimation using an unsupervised deep network with online error correction,
E. J. Shamwell, S. Leung, and W. D. Nothwang, “Vision-aided absolute trajectory estimation using an unsupervised deep network with online error correction,” in 2018 IEEE/RSJ International Conference on Intel- ligent Robots and Systems (IROS) . IEEE, 2018, pp. 2524–2531
2018
-
[44]
Measuring robustness of visual slam,
D. Prokhorov et al., “Measuring robustness of visual slam,” in 2019 16th International conference on machine vision applications (MVA) . IEEE, 2019
2019
-
[45]
Prediction and compensation of relative position error along industrial robot end-effector paths,
A. Angelidis and G.-C. V osniakos, “Prediction and compensation of relative position error along industrial robot end-effector paths,” Inter- national journal of precision engineering and manufacturing , vol. 15, pp. 63–73, 2014
2014
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