Enhanced Low-resolution LiDAR-Camera Calibration Via Depth Interpolation and Supervised Contrastive Learning
Arizona State University（亚利桑那州立大学）；U.S. Army DEVCOM Research Laboratory（美国陆军作战能力发展司令部研究实验室）；U.S. Army DEVCOM C5ISR Center（美国陆军作战能力发展司令部指挥、控制、通信、计算机、网络、情报、监视与侦察中心）
Motivated by the increasing application of low-resolution LiDAR recently, we target the problem of low-resolution LiDAR-camera calibration in this work. The main challenges are two-fold: sparsity and noise in point clouds. To address the problem, we propose to apply depth interpolation to increase the point density and supervised contrastive learning to learn noise-resistant features. The experiments on RELLIS-3D demonstrate that our approach achieves an average mean absolute rotation/translation errors of 0.15cm/0.33\textdegree on 32-channel LiDAR point cloud data, which significantly outperforms all reference methods.
Institute of Information Science, Beijing Jiaotong University（北京交通大学信息科学研究所）；College of Electronic Science and Technology, National University of Defense Technology（国防科技大学电子科学学院）
LiDAR sensors can provide dependable 3D spatial information at a low frequency (around 10Hz) and have been widely applied in the field of autonomous driving and UAV. However, the camera with a higher frequency (around 20Hz) has to be decreased so as to match with LiDAR in a multi-sensor system. In this paper, we propose a novel Pseudo-LiDAR interpolation network (PLIN) to increase the frequency of LiDAR sensors. PLIN can generate temporally and spatially high-quality point cloud sequences to match the high frequency of cameras. To achieve this goal, we design a coarse interpolation stage guide…
Beijing Jiaotong University（北京交通大学）；National University of Defense Technology（国防科技大学）
Pseudo-LiDAR point cloud interpolation is a novel and challenging task in the field of autonomous driving, which aims to address the frequency mismatching problem between camera and LiDAR. Previous works represent the 3D spatial motion relationship induced by a coarse 2D optical flow, and the quality of interpolated point clouds only depends on the supervision of depth maps. As a result, the generated point clouds suffer from inferior global distributions and local appearances. To solve the above problems, we propose a Pseudo-LiDAR point cloud interpolation network to generates temporally and …
Image and Point Clouds provide different information for robots. Finding the correspondences between data from different sensors is crucial for various tasks such as localization, mapping, and navigation. Learning-based descriptors have been developed for single sensors; there is little work on cross-modal features. This work treats learning cross-modal features as a dense contrastive learning problem. We propose a Tuple-Circle loss function for cross-modality feature learning. Furthermore, to learn good features and not lose generality, we developed a variant of widely used PointNet++ archite…
University of Electronic Science and Technology of China（电子科技大学）
LiDAR point cloud frame interpolation, which synthesizes the intermediate frame between the captured frames, has emerged as an important issue for many applications. Especially for reducing the amounts of point cloud transmission, it is by predicting the intermediate frame based on the reference frames to upsample data to high frame rate ones. However, due to high-dimensional and sparse characteristics of point clouds, it is more difficult to predict the intermediate frame for LiDAR point clouds than videos. In this paper, we propose a novel LiDAR point cloud frame interpolation method, which …
Tongji University（同济大学）；University of Science and Technology of China（中国科学技术大学）
LiDAR point cloud streams are usually sparse in time dimension, which is limited by hardware performance. Generally, the frame rates of mechanical LiDAR sensors are 10 to 20 Hz, which is much lower than other commonly used sensors like cameras. To overcome the temporal limitations of LiDAR sensors, a novel task named Point Cloud Frame Interpolation is studied in this paper. Given two consecutive point cloud frames, Point Cloud Frame Interpolation aims to generate intermediate frame(s) between them. To achieve that, we propose a novel framework, namely Point Cloud Frame Interpolation Network (P…
IRISA（法国信息与自动化研究所）；Université Bretagne Sud（南布列塔尼大学）；University of Salzburg（萨尔茨堡大学）
It is of interest to localize a ground-based LiDAR point cloud on remote sensing imagery. In this work, we tackle a subtask of this problem, i.e. to map a digital elevation model (DEM) rasterized from aerial LiDAR point cloud on the aerial imagery. We proposed a contrastive learning-based method that trains on DEM and high-resolution optical imagery and experiment the framework on different data sampling strategies and hyperparameters. In the best scenario, the Top-1 score of 0.71 and Top-5 score of 0.81 are obtained. The proposed method is promising for feature learning from RGB and DEM for l…
Constructing a point cloud for a large geographic region, such as a state or country, can require multiple years of effort. Often several vendors will be used to acquire LiDAR data, and a single region may be captured by multiple LiDAR scans. A key challenge is maintaining consistency between these scans, which includes point density, number of returns, and intensity. Intensity in particular can be very different between scans, even in areas that are overlapping. Harmonizing the intensity between scans to remove these discrepancies is expensive and time consuming. In this paper, we propose a n…
WeatherGen: A Unified Diverse Weather Generator for LiDAR Point Clouds via Spider Mamba Diffusion
PCA Lab, Nanjing University of Science and Technology（南京理工大学光电信息科学与工程实验室）；School of Automation, Southeast University（东南大学自动化学院）；State Key Laboratory for Novel Software Technology, Nanjing University（南京大学软件新技术国家重点实验室）；School of Intelligence Science and Technology, Nanjing University（南京大学智能科学与技术学院）
LiMoE: Mixture of LiDAR Representation Learners from Automotive Scenes
Nanjing University of Aeronautics and Astronautics（南京航空航天大学）；National University of Singapore（新加坡国立大学）；Shanghai AI Laboratory（上海人工智能实验室）；Nanjing University of Posts and Telecommunications（南京邮电大学）；S-Lab, Nanyang Technological University（南洋理工大学S-Lab）
Robust and accurate depth estimation by fusing LiDAR and Stereo
University of the Chinese Academy of Sciences（中国科学院大学）；Institute of Automation, Chinese Academy of Sciences（中国科学院自动化研究所）；Electric Power Research Institute, State Grid Shandong Electric Power Company（国网山东省电力公司电力科学研究院）
University of Science and Technology of China（中国科学技术大学）；Microsoft Research（微软研究院）；Simon Fraser University（西蒙弗雷泽大学）；Wormpex AI Research LLC（Wormpex人工智能研究有限责任公司）
Notwithstanding the prominent performance achieved in various applications, point cloud recognition models have often suffered from natural corruptions and adversarial perturbations. In this paper, we delve into boosting the general robustness of point cloud recognition models and propose Point-Cloud Contrastive Adversarial Training (PointCAT). The main intuition of PointCAT is encouraging the target recognition model to narrow the decision gap between clean point clouds and corrupted point clouds. Specifically, we leverage a supervised contrastive loss to facilitate the alignment and uniformi…
ContrastMotion: Self-supervised Scene Motion Learning for Large-Scale LiDAR Point Clouds
Nanjing University of Aeronautics and Astronautics（南京航空航天大学）；Rhino（犀牛（公司））；The Chinese University of Hong Kong（香港中文大学）；OPPO Research Institute（OPPO研究院）；Zhejiang Lab（之江实验室）；ShanghaiTech University（上海科技大学）
Nanyang Technological University（南洋理工大学）；Institute for Infocomm Research A*STAR（新加坡科技研究局资讯通信研究院）
LiDAR-based 3D scene perception is a fundamental and important task for autonomous driving. Most state-of-the-art methods on LiDAR-based 3D recognition tasks focus on single frame 3D point cloud data, and the temporal information is ignored in those methods. We argue that the temporal information across the frames provides crucial knowledge for 3D scene perceptions, especially in the driving scenario. In this paper, we focus on spatial and temporal variations to better explore the temporal information across the 3D frames. We design a temporal variation-aware interpolation module and a tempora…
CLLAP: Contrastive Learning-based LiDAR-Augmented Pretraining for Enhanced Radar-Camera Fusion
Wuhan University of Technology（武汉理工大学）；University of North Carolina at Charlotte（北卡罗来纳州立大学）；Wuhan University（武汉大学）；Southwest Jiaotong University（西南交通大学）；The Hong Kong Polytechnic University（香港理工大学）
Self-supervised learning (SSL) has the potential to benefit many applications, particularly those where manually annotating data is cumbersome. One such situation is the semantic segmentation of point clouds. In this context, existing methods employ contrastive learning strategies and define positive pairs by performing various augmentation of point clusters in a single frame. As such, these methods do not exploit the temporal nature of LiDAR data. In this paper, we introduce an SSL strategy that leverages positive pairs in both the spatial and temporal domain. To this end, we design (i) a poi…
GeoUniPR: A Geometry-Consistent Unified Framework for Cross-Modal Place Recognition
School of Computer Science and Technology, Tongji University（同济大学计算机科学与技术学院）；Shanghai Research Institute for Intelligent Autonomous System, Tongji University（同济大学上海智能自主系统研究院）；Shanghai Innovation Institute（上海创新研究院）
ENS Paris-Saclay（巴黎萨克雷高等师范学院）；Centre Borelli（博雷利中心）；Schlumberger AI Lab（斯伦贝谢人工智能实验室）
Self-supervised representation learning based on Contrastive Learning (CL) has been the subject of much attention in recent years. This is due to the excellent results obtained on a variety of subsequent tasks (in particular classification), without requiring a large amount of labeled samples. However, most reference CL algorithms (such as SimCLR and MoCo, but also BYOL and Barlow Twins) are not adapted to pixel-level downstream tasks. One existing solution known as PixPro proposes a pixel-level approach that is based on filtering of pairs of positive/negative image crops of the same image usi…
Ocean University of China（中国海洋大学）；Southwest Jiaotong University（西南交通大学）；Mississippi State University（密西西比州立大学）
The joint hyperspectral image (HSI) and LiDAR data classification aims to interpret ground objects at more detailed and precise level. Although deep learning methods have shown remarkable success in the multisource data classification task, self-supervised learning has rarely been explored. It is commonly nontrivial to build a robust self-supervised learning model for multisource data classification, due to the fact that the semantic similarities of neighborhood regions are not exploited in existing contrastive learning framework. Furthermore, the heterogeneous gap induced by the inconsistent …
Which Way from B to A: The role of embedding geometry in image interpolation for Stable Diffusion
Department of Mathematics University of California, San Diego（数学系 加州大学圣地亚哥分校）；National Security Directorate Pacific Northwest National Laboratory（国家安全局 西部国家实验室）；Earth and Biological Sciences Directorate Pacific Northwest National Laboratory（地球与生命科学局 西部国家实验室）
Projecting the point cloud on the 2D spherical range image transforms the LiDAR semantic segmentation to a 2D segmentation task on the range image. However, the LiDAR range image is still naturally different from the regular 2D RGB image; for example, each position on the range image encodes the unique geometry information. In this paper, we propose a new projection-based LiDAR semantic segmentation pipeline that consists of a novel network structure and an efficient post-processing step. In our network structure, we design a FID (fully interpolation decoding) module that directly upsamples th…
Geo-Registration of Terrestrial LiDAR Point Clouds with Satellite Images without GNSS
Department of Computer Science and Software Engineering, The University of Western Australia（计算机科学与软件工程系，西澳大学）；School of Engineering and Technology, University of New South Wales（工程与技术学院，新南威尔士大学）
Harbin Institute of Technology（哈尔滨工业大学）；University of Science and Technology（中国科学技术大学）；SenseTime Research（商汤科技研究院）；The Chinese University of Hong Kong（香港中文大学）；IIIS, Tsinghua University（清华大学交叉信息研究院）
Pre-training has become a standard paradigm in many computer vision tasks. However, most of the methods are generally designed on the RGB image domain. Due to the discrepancy between the two-dimensional image plane and the three-dimensional space, such pre-trained models fail to perceive spatial information and serve as sub-optimal solutions for 3D-related tasks. To bridge this gap, we aim to learn a spatial-aware visual representation that can describe the three-dimensional space and is more suitable and effective for these tasks. To leverage point clouds, which are much more superior in prov…
University of Coimbra（科英布拉大学）；Institute of Systems and Robotics（系统与机器人研究所）
High resolution depth-maps, obtained by upsampling sparse range data from a 3D-LIDAR, find applications in many fields ranging from sensory perception to semantic segmentation and object detection. Upsampling is often based on combining data from a monocular camera to compensate the low-resolution of a LIDAR. This paper, on the other hand, introduces a novel framework to obtain dense depth-map solely from a single LIDAR point cloud; which is a research direction that has been barely explored. The formulation behind the proposed depth-mapping process relies on local spatial interpolation, using…
ContrastAlign: Toward Robust BEV Feature Alignment via Contrastive Learning for Multi-Modal 3D Object Detection
School of Computer Science & Technology, Beijing Key Laboratory of Traffic Data Mining and Embodied Intelligence, Beijing Jiaotong University（计算机科学与技术学院，北京交通大数据挖掘与具身智能重点实验室，北京交通大学）；Horizon Robotics；Nanyang Technological University（南洋理工大学）；University of Macau（澳门大学）；School of Information Science and Engineering, Yanshan University（信息科学与工程学院，燕山大学）；School of Computer Science and Technology, Harbin Institute of Technology（计算机科学与技术学院，哈尔滨理工大学）；School of Information Technology and Electrical Engineering, The University of Queensland（信息技术与电气工程学院，昆士兰大学）
Semi-supervised learning (SSL) has long been proved to be an effective technique to construct powerful models with limited labels. In the existing literature, consistency regularization-based methods, which force the perturbed samples to have similar predictions with the original ones have attracted much attention for their promising accuracy. However, we observe that, the performance of such methods decreases drastically when the labels get extremely limited, e.g., 2 or 3 labels for each category. Our empirical study finds that the main problem lies with the drifting of semantic information i…
ItTakesTwo: Leveraging Peer Representations for Semi-supervised LiDAR Semantic Segmentation
Australian Institute for Machine Learning (AIML), University of Adelaide（澳大利亚机器学习研究所（AIML）、阿德莱德大学）；Mohamed bin Zayed University of Artificial Intelligence (MBZUAI)（穆罕默德·本·扎耶德人工智能大学）；University of Erlangen–Nuremberg（埃尔兰根-纽伦堡大学）；Centre for Vision, Speech and Signal Processing (CVSSP), University of Surrey, UK（视觉、语音和信号处理中心（CVSSP）、萨里大学）
Insight Centre for Data Analytics（数据分析洞察中心）；Dublin City University (DCU)（都柏林城市大学）
Deep neural networks trained with standard cross-entropy loss memorize noisy labels, which degrades their performance. Most research to mitigate this memorization proposes new robust classification loss functions. Conversely, we propose a Multi-Objective Interpolation Training (MOIT) approach that jointly exploits contrastive learning and classification to mutually help each other and boost performance against label noise. We show that standard supervised contrastive learning degrades in the presence of label noise and propose an interpolation training strategy to mitigate this behavior. We fu…
Mercedes-Benz AG（梅赛德斯-奔驰股份公司）；Karlsruhe Institute of Technology（卡尔斯鲁厄理工学院）；Research Center for Information Technology（信息技术研究中心）
Judging the quality of samples synthesized by generative models can be tedious and time consuming, especially for complex data structures, such as point clouds. This paper presents a novel approach to quantify the realism of local regions in LiDAR point clouds. Relevant features are learned from real-world and synthetic point clouds by training on a proxy classification task. Inspired by fair networks, we use an adversarial technique to discourage the encoding of dataset-specific information. The resulting metric can assign a quality score to samples without requiring any task specific annotat…
University of Macau（澳门大学）；Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences（中国科学院深圳先进技术研究院）；University of Chinese Academy of Sciences（中国科学院大学）；Baidu Research（百度研究院）
In this paper, we propose a learning-based moving-object tracking method utilizing our newly developed LiDAR sensor, Frequency Modulated Continuous Wave (FMCW) LiDAR. Compared with most existing commercial LiDAR sensors, our FMCW LiDAR can provide additional Doppler velocity information to each 3D point of the point clouds. Benefiting from this, we can generate instance labels as ground truth in a semi-automatic manner. Given the labels, we propose a contrastive learning framework, which pulls together the features from the same instance in embedding space and pushes apart the features from di…
Self-Supervised Moving Object Segmentation of Sparse and Noisy Radar Point Clouds
CARIAD SE（CARIAD公司）；TU Dortmund University（杜伊斯堡-艾森大学）；University of Bonn（波恩大学）；Lamarr Institute for Machine Learning and Artificial Intelligence（拉马尔人工智能与机器学习研究所）
4D Contrastive Superflows are Dense 3D Representation Learners
Nanjing University of Aeronautics and Astronautics（南京航空航天大学）；Shanghai AI Laboratory（上海人工智能实验室）；National University of Singapore（新加坡国立大学）；Nanjing University of Posts and Telecommunications（南京邮电大学）；S-Lab, Nanyang Technological University（南洋理工大学S-Lab（注：S-Lab为南洋理工大学下属实验室，按要求提取到大学/研究院级别，此处保留原文机构名及对应翻译））
RaCalNet: Radar Calibration Network for Sparse-Supervised Metric Depth Estimation
School of Automation and Intelligent Sensing, Institute of Medical Robotics, Shanghai Jiao Tong University, Shanghai 200240, China（上海交通大学自动化与智能感知学院，医学机器人研究所）；School of Mathematical Sciences, Shanghai Jiao Tong University, Shanghai, China（上海交通大学数学科学学院）；South China University of Technology, Guangzhou, China（华南理工大学）；State Grid Intelligence Technology CO., LTD（国家电网智能技术有限公司）
LIGM（法国巴黎东区大学信息与数学实验室）；Ecole des Ponts（巴黎路桥学院）；Univ. Gustave Eiffel（古斯塔夫·埃菲尔大学）；CNRS（法国国家科学研究中心）
Segmenting or detecting objects in sparse Lidar point clouds are two important tasks in autonomous driving to allow a vehicle to act safely in its 3D environment. The best performing methods in 3D semantic segmentation or object detection rely on a large amount of annotated data. Yet annotating 3D Lidar data for these tasks is tedious and costly. In this context, we propose a self-supervised pre-training method for 3D perception models that is tailored to autonomous driving data. Specifically, we leverage the availability of synchronized and calibrated image and Lidar sensors in autonomous dri…
CO^3: Cooperative Unsupervised 3D Representation Learning for Autonomous Driving
The University of Hong Kong（香港大学）；Shanghai AI Laboratory（上海人工智能实验室）；Huawei Noah’s Ark Lab（华为诺亚实验室）；The Chinese University of Hong Kong（香港中文大学）；Hong Kong University of Science and Technology（香港科技大学）
Institute of Information Engineering, Chinese Academy of Sciences（中国科学院信息工程研究所）；School of Cyber Security, University of Chinese Academy of Sciences（中国科学院大学网络空间安全学院）；School of Electronic, Electrical, and Communication Engineering, University of Chinese Academy of Sciences（中国科学院大学电子电气与通信工程学院）；Department of Automation, Tsinghua University（清华大学自动化系）
Contrastive self-supervised learning (CSL) based on instance discrimination typically attracts positive samples while repelling negatives to learn representations with pre-defined binary self-supervision. However, vanilla CSL is inadequate in modeling sophisticated instance relations, limiting the learned model to retain fine semantic structure. On the one hand, samples with the same semantic category are inevitably pushed away as negatives. On the other hand, differences among samples cannot be captured. In this paper, we present relation-aware contrastive self-supervised learning (ReCo) to i…
