GenAI4ELab/papercli-papers huggingface dataset:
RadSimReal: Bridging the Gap Between Synthetic and Real Data in Radar Object Detection With Simulation
Authors: Oded Bialer; Yuval Haitman
Venue: CVPR 2024 (main)

Abstract: Object detection in radar imagery with neural networks shows great potential for improving autonomous driving. However obtaining annotated datasets from real radar images crucial for training these networks is challenging especially in scenarios with long-range detection and adverse weather and lighting conditions where radar performance excels. To address this challenge we present RadSimReal an innovative physical radar simulation capable of generating synthetic radar images with accompanying annotations for various radar types and environmental conditions all without the need for real data collection. Remarkably our findings demonstrate that training object detection models on RadSimReal data and subsequently evaluating them on real-world data produce performance levels comparable to models trained and tested on real data from the same dataset and even achieves better performance when testing across different real datasets. RadSimReal offers advantages over other physical radar simulations that it does not necessitate knowledge of the radar design details which are often not disclosed by radar suppliers and has faster run-time. This innovative tool has the potential to advance the development of computer vision algorithms for radar-based autonomous driving applications.
No More Ambiguity in 360deg Room Layout via Bi-Layout Estimation
Authors: Yu-Ju Tsai; Jin-Cheng Jhang; Jingjing Zheng; Wei Wang; Albert Y. C. Chen; Min Sun; Cheng-Hao Kuo; Ming-Hsuan Yang
Venue: CVPR 2024 (main)

Abstract: Inherent ambiguity in layout annotations poses significant challenges to developing accurate 360deg room layout estimation models. To address this issue we propose a novel Bi-Layout model capable of predicting two distinct layout types. One stops at ambiguous regions while the other extends to encompass all visible areas. Our model employs two global context embeddings where each embedding is designed to capture specific contextual information for each layout type. With our novel feature guidance module the image feature retrieves relevant context from these embeddings generating layout-aware features for precise bi-layout predictions. A unique property of our Bi-Layout model is its ability to inherently detect ambiguous regions by comparing the two predictions. To circumvent the need for manual correction of ambiguous annotations during testing we also introduce a new metric for disambiguating ground truth layouts. Our method demonstrates superior performance on benchmark datasets notably outperforming leading approaches. Specifically on the MatterportLayout dataset it improves 3DIoU from 81.70% to 82.57% across the full test set and notably from 54.80% to 59.97% in subsets with significant ambiguity.
Residual Denoising Diffusion Models
Authors: Jiawei Liu; Qiang Wang; Huijie Fan; Yinong Wang; Yandong Tang; Liangqiong Qu
Venue: CVPR 2024 (main)

Abstract: We propose residual denoising diffusion models (RDDM) a novel dual diffusion process that decouples the traditional single denoising diffusion process into residual diffusion and noise diffusion. This dual diffusion framework expands the denoising-based diffusion models initially uninterpretable for image restoration into a unified and interpretable model for both image generation and restoration by introducing residuals. Specifically our residual diffusion represents directional diffusion from the target image to the degraded input image and explicitly guides the reverse generation process for image restoration while noise diffusion represents random perturbations in the diffusion process. The residual prioritizes certainty while the noise emphasizes diversity enabling RDDM to effectively unify tasks with varying certainty or diversity requirements such as image generation and restoration. We demonstrate that our sampling process is consistent with that of DDPM and DDIM through coefficient transformation and propose a partially path-independent generation process to better understand the reverse process. Notably our RDDM enables a generic UNet trained with only an L1 loss and a batch size of 1 to compete with state-of-the-art image restoration methods. We provide code and pre-trained models to encourage further exploration application and development of our innovative framework (https://github.com/nachifur/RDDM).
Towards Accurate and Robust Architectures via Neural Architecture Search
Authors: Yuwei Ou; Yuqi Feng; Yanan Sun
Venue: CVPR 2024 (main)

Abstract: To defend deep neural networks from adversarial attacks adversarial training has been drawing increasing attention for its effectiveness. However the accuracy and robustness resulting from the adversarial training are limited by the architecture because adversarial training improves accuracy and robustness by adjusting the weight connection affiliated to the architecture. In this work we propose ARNAS to search for accurate and robust architectures for adversarial training. First we design an accurate and robust search space in which the placement of the cells and the proportional relationship of the filter numbers are carefully determined. With the design the architectures can obtain both accuracy and robustness by deploying accurate and robust structures to their sensitive positions respectively. Then we propose a differentiable multi-objective search strategy performing gradient descent towards directions that are beneficial for both natural loss and adversarial loss thus the accuracy and robustness can be guaranteed at the same time. We conduct comprehensive experiments in terms of white-box attacks black-box attacks and transferability. Experimental results show that the searched architecture has the strongest robustness with the competitive accuracy and breaks the traditional idea that NAS-based architectures cannot transfer well to complex tasks in robustness scenarios. By analyzing outstanding architectures searched we also conclude that accurate and robust neural architectures tend to deploy different structures near the input and output which has great practical significance on both hand-crafting and automatically designing of accurate and robust architectures.
Closely Interactive Human Reconstruction with Proxemics and Physics-Guided Adaption
Authors: Buzhen Huang; Chen Li; Chongyang Xu; Liang Pan; Yangang Wang; Gim Hee Lee
Venue: CVPR 2024 (main)

Abstract: Existing multi-person human reconstruction approaches mainly focus on recovering accurate poses or avoiding penetration but overlook the modeling of close interactions. In this work we tackle the task of reconstructing closely interactive humans from a monocular video. The main challenge of this task comes from insufficient visual information caused by depth ambiguity and severe inter-person occlusion. In view of this we propose to leverage knowledge from proxemic behavior and physics to compensate the lack of visual information. This is based on the observation that human interaction has specific patterns following the social proxemics. Specifically we first design a latent representation based on Vector Quantised-Variational AutoEncoder (VQ-VAE) to model human interaction. A proxemics and physics guided diffusion model is then introduced to denoise the initial distribution. We design the diffusion model as dual branch with each branch representing one individual such that the interaction can be modeled via cross attention. With the learned priors of VQ-VAE and physical constraint as the additional information our proposed approach is capable of estimating accurate poses that are also proxemics and physics plausible. Experimental results on Hi4D 3DPW and CHI3D demonstrate that our method outperforms existing approaches. The code is available at https://github.com/boycehbz/HumanInteraction.
A Noisy Elephant in the Room: Is Your Out-of-Distribution Detector Robust to Label Noise?
Authors: Galadrielle Humblot-Renaux; Sergio Escalera; Thomas B. Moeslund
Venue: CVPR 2024 (main)

Abstract: The ability to detect unfamiliar or unexpected images is essential for safe deployment of computer vision systems. In the context of classification the task of detecting images outside of a model's training domain is known as out-of-distribution (OOD) detection. While there has been a growing research interest in developing post-hoc OOD detection methods there has been comparably little discussion around how these methods perform when the underlying classifier is not trained on a clean carefully curated dataset. In this work we take a closer look at 20 state-of-the-art OOD detection methods in the (more realistic) scenario where the labels used to train the underlying classifier are unreliable (e.g. crowd-sourced or web-scraped labels). Extensive experiments across different datasets noise types & levels architectures and checkpointing strategies provide insights into the effect of class label noise on OOD detection and show that poor separation between incorrectly classified ID samples vs. OOD samples is an overlooked yet important limitation of existing methods. Code: https://github.com/glhr/ood-labelnoise
VideoMAC: Video Masked Autoencoders Meet ConvNets
Authors: Gensheng Pei; Tao Chen; Xiruo Jiang; Huafeng Liu; Zeren Sun; Yazhou Yao
Venue: CVPR 2024 (main)

Abstract: Recently the advancement of self-supervised learning techniques like masked autoencoders (MAE) has greatly influenced visual representation learning for images and videos. Nevertheless it is worth noting that the predominant approaches in existing masked image / video modeling rely excessively on resource-intensive vision transformers (ViTs) as the feature encoder. In this paper we propose a new approach termed as VideoMAC which combines video masked autoencoders with resource-friendly ConvNets. Specifically VideoMAC employs symmetric masking on randomly sampled pairs of video frames. To prevent the issue of mask pattern dissipation we utilize ConvNets which are implemented with sparse convolutional operators as encoders. Simultaneously we present a simple yet effective masked video modeling (MVM) approach a dual encoder architecture comprising an online encoder and an exponential moving average target encoder aimed to facilitate inter-frame reconstruction consistency in videos. Additionally we demonstrate that VideoMAC empowering classical (ResNet) / modern (ConvNeXt) convolutional encoders to harness the benefits of MVM outperforms ViT-based approaches on downstream tasks including video object segmentation (+5.2% / 6.4% \mathcal J &\mathcal F ) body part propagation (+6.3% / 3.1% mIoU) and human pose tracking (+10.2% / 11.1% PCK@0.1).
Taming Stable Diffusion for Text to 360 Panorama Image Generation
Authors: Cheng Zhang; Qianyi Wu; Camilo Cruz Gambardella; Xiaoshui Huang; Dinh Phung; Wanli Ouyang; Jianfei Cai
Venue: CVPR 2024 (main)

Abstract: Generative models e.g. Stable Diffusion have enabled the creation of photorealistic images from text prompts. Yet the generation of 360-degree panorama images from text remains a challenge particularly due to the dearth of paired text-panorama data and the domain gap between panorama and perspective images. In this paper we introduce a novel dual-branch diffusion model named PanFusion to generate a 360-degree image from a text prompt. We leverage the stable diffusion model as one branch to provide prior knowledge in natural image generation and register it to another panorama branch for holistic image generation. We propose a unique cross-attention mechanism with projection awareness to minimize distortion during the collaborative denoising process. Our experiments validate that PanFusion surpasses existing methods and thanks to its dual-branch structure can integrate additional constraints like room layout for customized panorama outputs.
3DSFLabelling: Boosting 3D Scene Flow Estimation by Pseudo Auto-labelling
Authors: Chaokang Jiang; Guangming Wang; Jiuming Liu; Hesheng Wang; Zhuang Ma; Zhenqiang Liu; Zhujin Liang; Yi Shan; Dalong Du
Venue: CVPR 2024 (main)

Abstract: Learning 3D scene flow from LiDAR point clouds presents significant difficulties including poor generalization from synthetic datasets to real scenes scarcity of real-world 3D labels and poor performance on real sparse LiDAR point clouds. We present a novel approach from the perspective of auto-labelling aiming to generate a large number of 3D scene flow pseudo labels for real-world LiDAR point clouds. Specifically we employ the assumption of rigid body motion to simulate potential object-level rigid movements in autonomous driving scenarios. By updating different motion attributes for multiple anchor boxes the rigid motion decomposition is obtained for the whole scene. Furthermore we developed a novel 3D scene flow data augmentation method for global and local motion. By perfectly synthesizing target point clouds based on augmented motion parameters we easily obtain lots of 3D scene flow labels in point clouds highly consistent with real scenarios. On multiple real-world datasets including LiDAR KITTI nuScenes and Argoverse our method outperforms all previous supervised and unsupervised methods without requiring manual labelling. Impressively our method achieves a tenfold reduction in EPE3D metric on the LiDAR KITTI dataset reducing it from 0.190m to a mere 0.008m error.
Unsigned Orthogonal Distance Fields: An Accurate Neural Implicit Representation for Diverse 3D Shapes
Authors: Yujie Lu; Long Wan; Nayu Ding; Yulong Wang; Shuhan Shen; Shen Cai; Lin Gao
Venue: CVPR 2024 (main)

Abstract: Neural implicit representation of geometric shapes has witnessed considerable advancements in recent years. However common distance field based implicit representations specifically signed distance field (SDF) for watertight shapes or unsigned distance field (UDF) for arbitrary shapes routinely suffer from degradation of reconstruction accuracy when converting to explicit surface points and meshes. In this paper we introduce a novel neural implicit representation based on unsigned orthogonal distance fields (UODFs). In UODFs the minimal unsigned distance from any spatial point to the shape surface is defined solely in one orthogonal direction contrasting with the multi-directional determination made by SDF and UDF. Consequently every point in the 3D UODFs can directly access its closest surface points along three orthogonal directions. This distinctive feature leverages the accurate reconstruction of surface points without interpolation errors. We verify the effectiveness of UODFs through a range of reconstruction examples extending from simple watertight or non-watertight shapes to complex shapes that include hollows internal or assembling structures.
Modular Blind Video Quality Assessment
Authors: Wen Wen; Mu Li; Yabin Zhang; Yiting Liao; Junlin Li; Li Zhang; Kede Ma
Venue: CVPR 2024 (main)

Abstract: Blind video quality assessment (BVQA) plays a pivotal role in evaluating and improving the viewing experience of end-users across a wide range of video-based platforms and services. Contemporary deep learning-based models primarily analyze video content in its aggressively subsampled format while being blind to the impact of the actual spatial resolution and frame rate on video quality. In this paper we propose a modular BVQA model and a method of training it to improve its modularity. Our model comprises a base quality predictor a spatial rectifier and a temporal rectifier responding to the visual content and distortion spatial resolution and frame rate changes on video quality respectively. During training spatial and temporal rectifiers are dropped out with some probabilities to render the base quality predictor a standalone BVQA model which should work better with the rectifiers. Extensive experiments on both professionally-generated content and user-generated content video databases show that our quality model achieves superior or comparable performance to current methods. Additionally the modularity of our model offers an opportunity to analyze existing video quality databases in terms of their spatial and temporal complexity.
Question Aware Vision Transformer for Multimodal Reasoning
Authors: Roy Ganz; Yair Kittenplon; Aviad Aberdam; Elad Ben Avraham; Oren Nuriel; Shai Mazor; Ron Litman
Venue: CVPR 2024 (main)

Abstract: Vision-Language (VL) models have gained significant research focus enabling remarkable advances in multimodal reasoning. These architectures typically comprise a vision encoder a Large Language Model (LLM) and a projection module that aligns visual features with the LLM's representation space. Despite their success a critical limitation persists: the vision encoding process remains decoupled from user queries often in the form of image-related questions. Consequently the resulting visual features may not be optimally attuned to the query-specific elements of the image. To address this we introduce QA-ViT a Question Aware Vision Transformer approach for multimodal reasoning which embeds question awareness directly within the vision encoder. This integration results in dynamic visual features focusing on relevant image aspects to the posed question. QA-ViT is model-agnostic and can be incorporated efficiently into any VL architecture. Extensive experiments demonstrate the effectiveness of applying our method to various multimodal architectures leading to consistent improvement across diverse tasks and showcasing its potential for enhancing visual and scene-text understanding.
OST: Refining Text Knowledge with Optimal Spatio-Temporal Descriptor for General Video Recognition
Authors: Tongjia Chen; Hongshan Yu; Zhengeng Yang; Zechuan Li; Wei Sun; Chen Chen
Venue: CVPR 2024 (main)

Abstract: Due to the resource-intensive nature of training vision-language models on expansive video data a majority of studies have centered on adapting pre-trained image-language models to the video domain. Dominant pipelines propose to tackle the visual discrepancies with additional temporal learners while overlooking the substantial discrepancy for web-scaled descriptive narratives and concise action category names leading to less distinct semantic space and potential performance limitations. In this work we prioritize the refinement of text knowledge to facilitate generalizable video recognition. To address the limitations of the less distinct semantic space of category names we prompt a large language model (LLM) to augment action class names into Spatio-Temporal Descriptors thus bridging the textual discrepancy and serving as a knowledge base for general recognition. Moreover to assign the best descriptors with different video instances we propose Optimal Descriptor Solver forming the video recognition problem as solving the optimal matching flow across frame-level representations and descriptors. Comprehensive evaluations in zero-shot few-shot and fully supervised video recognition highlight the effectiveness of our approach. Our best model achieves a state-of-the-art zero-shot accuracy of 75.1% on Kinetics-600.
Habitat Synthetic Scenes Dataset (HSSD-200): An Analysis of 3D Scene Scale and Realism Tradeoffs for ObjectGoal Navigation
Authors: Mukul Khanna; Yongsen Mao; Hanxiao Jiang; Sanjay Haresh; Brennan Shacklett; Dhruv Batra; Alexander Clegg; Eric Undersander; Angel X. Chang; Manolis Savva
Venue: CVPR 2024 (main)

Abstract: We contribute the Habitat Synthetic Scene Dataset a dataset of 211 high-quality 3D scenes and use it to test navigation agent generalization to realistic 3D environments. Our dataset represents real interiors and contains a diverse set of 18656 models of real-world objects. We investigate the impact of synthetic 3D scene dataset scale and realism on the task of training embodied agents to find and navigate to objects (ObjectGoal navigation). By comparing to synthetic 3D scene datasets from prior work we find that scale helps in generalization but the benefits quickly saturate making visual fidelity and correlation to real-world scenes more important. Our experiments show that agents trained on our smaller-scale dataset can match or outperform agents trained on much larger datasets. Surprisingly we observe that agents trained on just 122 scenes from our dataset outperform agents trained on 10000 scenes from the ProcTHOR-10K dataset in terms of zero-shot generalization in real-world scanned environments.
OA-CNNs: Omni-Adaptive Sparse CNNs for 3D Semantic Segmentation
Authors: Bohao Peng; Xiaoyang Wu; Li Jiang; Yukang Chen; Hengshuang Zhao; Zhuotao Tian; Jiaya Jia
Venue: CVPR 2024 (main)

Abstract: The booming of 3D recognition in the 2020s began with the introduction of point cloud transformers. They quickly overwhelmed sparse CNNs and became state-of-the-art models especially in 3D semantic segmentation. However sparse CNNs are still valuable networks due to their efficiency treasure and ease of application. In this work we reexamine the design distinctions and test the limits of what a sparse CNN can achieve. We discover that the key credit to the performance difference is adaptivity. Specifically we propose two key components i.e. adaptive receptive fields (spatially) and adaptive relation to bridge the gap. This exploration led to the creation of Omni-Adaptive 3D CNNs (OA-CNNs) a family of networks that integrates a lightweight module to greatly enhance the adaptivity of sparse CNNs at minimal computational cost. Without any self-attention modules OA-CNNs favorably surpass point transformers in terms of accuracy in both indoor and outdoor scenes with much less latency and memory cost. Notably it achieves 76.1% 78.9% and 70.6% mIoU on ScanNet v2 nuScenes and SemanticKITTI validation benchmarks respectively while maintaining at most 5x better speed than transformer counterparts. This revelation highlights the potential of pure sparse CNNs to outperform transformer-related networks. Our code is built upon Pointcept which is available at https://github.com/Pointcept/Pointcept.
RELI11D: A Comprehensive Multimodal Human Motion Dataset and Method
Authors: Ming Yan; Yan Zhang; Shuqiang Cai; Shuqi Fan; Xincheng Lin; Yudi Dai; Siqi Shen; Chenglu Wen; Lan Xu; Yuexin Ma; Cheng Wang
Venue: CVPR 2024 (main)

Abstract: Comprehensive capturing of human motions requires both accurate captures of complex poses and precise localization of the human within scenes. Most of the HPE datasets and methods primarily rely on RGB LiDAR or IMU data. However solely using these modalities or a combination of them may not be adequate for HPE particularly for complex and fast movements. For holistic human motion understanding we present RELI11D a high-quality multimodal human motion dataset involves LiDAR IMU system RGB camera and Event camera. It records the motions of 10 actors performing 5 sports in 7 scenes including 3.32 hours of synchronized LiDAR point clouds IMU measurement data RGB videos and Event steams. Through extensive experiments we demonstrate that the RELI11D presents considerable challenges and opportunities as it contains many rapid and complex motions that require precise location. To address the challenge of integrating different modalities we propose LEIR a multimodal baseline that effectively utilizes LiDAR Point Cloud Event stream and RGB through our cross-attention fusion strategy. We show that LEIR exhibits promising results for rapid motions and daily motions and that utilizing the characteristics of multiple modalities can indeed improve HPE performance. Both the dataset and source code will be released publicly to the research community fostering collaboration and enabling further exploration in this field.