pwc-archive/papers-with-abstracts huggingface dataset:
Not All Prompts Are Secure: A Switchable Backdoor Attack Against Pre-trained Vision Transfomers
Authors: Sheng Yang, Jiawang Bai, Kuofeng Gao, Yong Yang, Yiming Li, Shu-Tao Xia
Date: 2024-01-01 00:00:00
Proceeding: CVPR 2024 1
Tasks: All, Backdoor Attack

    Given the power of vision transformers a new learning paradigm pre-training and then prompting makes it more efficient and effective to address downstream visual recognition tasks. In this paper we identify a novel security threat towards such a paradigm from the perspective of backdoor attacks. Specifically an extra prompt token called the switch token in this work can turn the backdoor mode on i.e. converting a benign model into a backdoored one. Once under the backdoor mode a specific trigger can force the model to predict a target class. It poses a severe risk to the users of cloud API since the malicious behavior can not be activated and detected under the benign mode thus making the attack very stealthy. To attack a pre-trained model our proposed attack named SWARM learns a trigger and prompt tokens including a switch token. They are optimized with the clean loss which encourages the model always behaves normally even the trigger presents and the backdoor loss that ensures the backdoor can be activated by the trigger when the switch is on. Besides we utilize the cross-mode feature distillation to reduce the effect of the switch token on clean samples. The experiments on diverse visual recognition tasks confirm the success of our switchable backdoor attack i.e. achieving 95%+ attack success rate and also being hard to be detected and removed. Our code is available at https://github.com/20000yshust/SWARM.
Blind Image Quality Assessment Based on Geometric Order Learning
Authors: Nyeong-Ho Shin, Seon-Ho Lee, Chang-Su Kim
Date: 2024-01-01 00:00:00
Proceeding: CVPR 2024 1
Tasks: Image Quality Assessment, No-Reference Image Quality Assessment

    A novel approach to blind image quality assessment called quality comparison network (QCN) is proposed in this paper which sorts the feature vectors of input images according to their quality scores in an embedding space. QCN employs comparison transformers (CTs) and score pivots which act as the centroids of feature vectors of similar-quality images. Each CT updates the score pivots and the feature vectors of input images based on their ordered correlation. To this end we adopt four loss functions. Then we estimate the quality score of a test image by searching the nearest score pivot to its feature vector in the embedding space. Extensive experiments show that the proposed QCN algorithm yields excellent image quality assessment performances on various datasets. Furthermore QCN achieves great performances in cross-dataset evaluation demonstrating its superb generalization capability. The source codes are available at https://github.com/nhshin-mcl/QCN.
Point Segment and Count: A Generalized Framework for Object Counting
Authors: Zhizhong Huang, Mingliang Dai, Yi Zhang, Junping Zhang, Hongming Shan
Date: 2024-01-01 00:00:00
Proceeding: CVPR 2024 1
Tasks: Few-shot Object Counting and Detection, Knowledge Distillation, Object, Object Counting, Object Localization, Zero-Shot Counting

    Class-agnostic object counting aims to count all objects in an image with respect to example boxes or class names a.k.a few-shot and zero-shot counting. In this paper we propose a generalized framework for both few-shot and zero-shot object counting based on detection. Our framework combines the superior advantages of two foundation models without compromising their zero-shot capability: (i) SAM to segment all possible objects as mask proposals and (ii) CLIP to classify proposals to obtain accurate object counts. However this strategy meets the obstacles of efficiency overhead and the small crowded objects that cannot be localized and distinguished. To address these issues our framework termed PseCo follows three steps: point segment and count. Specifically we first propose a class-agnostic object localization to provide accurate but least point prompts for SAM which consequently not only reduces computation costs but also avoids missing small objects. Furthermore we propose a generalized object classification that leverages CLIP image/text embeddings as the classifier following a hierarchical knowledge distillation to obtain discriminative classifications among hierarchical mask proposals. Extensive experimental results on FSC-147 COCO and LVIS demonstrate that PseCo achieves state-of-the-art performance in both few-shot/zero-shot object counting/detection.
FACT: Frame-Action Cross-Attention Temporal Modeling for Efficient Action Segmentation
Authors: Zijia Lu, Ehsan Elhamifar
Date: 2024-01-01 00:00:00
Proceeding: CVPR 2024 1
Tasks: Action Segmentation, Segmentation

    We study supervised action segmentation whose goal is to predict framewise action labels of a video. To capture temporal dependencies over long horizons prior works either improve framewise features with transformer or refine framewise predictions with learned action features. However they are computationally costly and ignore that frame and action features contain complimentary information which can be leveraged to enhance both features and improve temporal modeling. Therefore we propose an efficient Frame-Action Cross-attention Temporal modeling (FACT) framework that performs temporal modeling with frame and action features in parallel and leverage this parallelism to achieve iterative bidirectional information transfer between the features and refine them. FACT network contains (i) a frame branch to learn frame-level information with convolutions and frame features (ii) an action branch to learn action-level dependencies with transformers and action tokens and (iii) cross-attentions to allow communication between the two branches. We also propose a new matching loss to ensure each action token uniquely encodes an action segment thus better captures its semantics. Thanks to our architecture we can also leverage textual transcripts of videos to help action segmentation. We evaluate FACT on four video datasets (two egocentric and two third-person) for action segmentation with and without transcripts showing that it significantly improves the state-of-the-art accuracy while enjoys lower computational cost (3 times faster) than existing transformer-based methods
IPoD: Implicit Field Learning with Point Diffusion for Generalizable 3D Object Reconstruction from Single RGB-D Images
Authors: Yushuang Wu, Luyue Shi, Junhao Cai, Weihao Yuan, Lingteng Qiu, Zilong Dong, Liefeng Bo, Shuguang Cui, Xiaoguang Han
Date: 2024-01-01 00:00:00
Proceeding: CVPR 2024 1
Tasks: 3D Object Reconstruction, Denoising, Object Reconstruction

    Generalizable 3D object reconstruction from single-view RGB-D images remains a challenging task particularly with real-world data. Current state-of-the-art methods develop Transformer-based implicit field learning necessitating an intensive learning paradigm that requires dense query-supervision uniformly sampled throughout the entire space. We propose a novel approach IPoD which harmonizes implicit field learning with point diffusion. This approach treats the query points for implicit field learning as a noisy point cloud for iterative denoising allowing for their dynamic adaptation to the target object shape. Such adaptive query points harness diffusion learning's capability for coarse shape recovery and also enhances the implicit representation's ability to delineate finer details. Besides an additional self-conditioning mechanism is designed to use implicit predictions as the guidance of diffusion learning leading to a cooperative system. Experiments conducted on the CO3D-v2 dataset affirm the superiority of IPoD achieving 7.8% improvement in F-score and 28.6% in Chamfer distance over existing methods. The generalizability of IPoD is also demonstrated on the MVImgNet dataset. Our project page is at https://yushuang-wu.github.io/IPoD.
Multimodal Prompt Perceiver: Empower Adaptiveness Generalizability and Fidelity for All-in-One Image Restoration
Authors: Yuang Ai, Huaibo Huang, Xiaoqiang Zhou, Jiexiang Wang, Ran He
Date: 2024-01-01 00:00:00
Proceeding: CVPR 2024 1
Tasks: All, Decoder, Image Restoration, Prompt Learning

    Despite substantial progress all-in-one image restoration (IR) grapples with persistent challenges in handling intricate real-world degradations. This paper introduces MPerceiver: a novel multimodal prompt learning approach that harnesses Stable Diffusion (SD) priors to enhance adaptiveness generalizability and fidelity for all-in-one image restoration. Specifically we develop a dual-branch module to master two types of SD prompts: textual for holistic representation and visual for multiscale detail representation. Both prompts are dynamically adjusted by degradation predictions from the CLIP image encoder enabling adaptive responses to diverse unknown degradations. Moreover a plug-in detail refinement module improves restoration fidelity via direct encoder-to-decoder information transformation. To assess our method MPerceiver is trained on 9 tasks for all-in-one IR and outperforms state-of-the-art task-specific methods across many tasks. Post multitask pre-training MPerceiver attains a generalized representation in low-level vision exhibiting remarkable zero-shot and few-shot capabilities in unseen tasks. Extensive experiments on 16 IR tasks underscore the superiority of MPerceiver in terms of adaptiveness generalizability and fidelity.
Multi-agent Collaborative Perception via Motion-aware Robust Communication Network
Authors: Shixin Hong, Yu Liu, Zhi Li, Shaohui Li, You He
Date: 2024-01-01 00:00:00
Proceeding: CVPR 2024 1
Tasks: 3D Object Detection, object-detection, Object Detection

    Collaborative perception allows for information sharing between multiple agents such as vehicles and infrastructure to obtain a comprehensive view of the environment through communication and fusion. Current research on multi-agent collaborative perception systems often assumes ideal communication and perception environments and neglects the effect of real-world noise such as pose noise motion blur and perception noise. To address this gap in this paper we propose a novel motion-aware robust communication network (MRCNet) that mitigates noise interference and achieves accurate and robust collaborative perception. MRCNet consists of two main components: multi-scale robust fusion (MRF) addresses pose noise by developing cross-semantic multi-scale enhanced aggregation to fuse features of different scales while motion enhanced mechanism (MEM) captures motion context to compensate for information blurring caused by moving objects. Experimental results on popular collaborative 3D object detection datasets demonstrate that MRCNet outperforms competing methods in noisy scenarios with improved perception performance using less bandwidth.
PAIR Diffusion: A Comprehensive Multimodal Object-Level Image Editor
Authors: Vidit Goel, Elia Peruzzo, Yifan Jiang, Dejia Xu, Xingqian Xu, Nicu Sebe, Trevor Darrell, Zhangyang Wang, Humphrey Shi
Date: 2024-01-01 00:00:00
Proceeding: CVPR 2024 1
Tasks: Object

    Generative image editing has recently witnessed extremely fast-paced growth. Some works use high-level conditioning such as text while others use low-level conditioning. Nevertheless most of them lack fine-grained control over the properties of the different objects present in the image i.e. object-level image editing. In this work we tackle the task by perceiving the images as an amalgamation of various objects and aim to control the properties of each object in a fine-grained manner. Out of these properties we identify structure and appearance as the most intuitive to understand and useful for editing purposes. We propose PAIR Diffusion a generic framework that enables a diffusion model to control the structure and appearance properties of each object in the image. We show that having control over the properties of each object in an image leads to comprehensive editing capabilities. Our framework allows for various object-level editing operations on real images such as reference image-based appearance editing free-form shape editing adding objects and variations. Thanks to our design we do not require any inversion step. Additionally we propose multimodal classifier-free guidance which enables editing images using both reference images and text when using our approach with foundational diffusion models. We validate the above claims by extensively evaluating our framework on both unconditional and foundational diffusion models.
Low-power Continuous Remote Behavioral Localization with Event Cameras
Authors: Friedhelm Hamann, Suman Ghosh, Ignacio Juarez Martinez, Tom Hart, Alex Kacelnik, Guillermo Gallego
Date: 2024-01-01 00:00:00
Proceeding: CVPR 2024 1
Tasks: Action Detection

    Researchers in natural science need reliable methods for quantifying animal behavior. Recently numerous computer vision methods emerged to automate the process. However observing wild species at remote locations remains a challenging task due to difficult lighting conditions and constraints on power supply and data storage. Event cameras offer unique advantages for battery-dependent remote monitoring due to their low power consumption and high dynamic range capabilities. We use this novel sensor to quantify a behavior in Chinstrap penguins called ecstatic display. We formulate the problem as a temporal action detection task determining the start and end times of the behavior. For this purpose we recorded a colony of breeding penguins in Antarctica for several weeks and labeled event data on 16 nests. The developed method consists of a generator of candidate time intervals (proposals) and a classifier of the actions within them. The experiments show that the event cameras' natural response to motion is effective for continuous behavior monitoring and detection reaching a mean average precision (mAP) of 58% (which increases to 63% in good weather conditions). The results also demonstrate the robustness against various lighting conditions contained in the challenging dataset. The low-power capabilities of the event camera allow it to record significantly longer than with a conventional camera. This work pioneers the use of event cameras for remote wildlife observation opening new interdisciplinary opportunities. https:// tub-rip.github.io/ eventpenguins/
MaskCLR: Attention-Guided Contrastive Learning for Robust Action Representation Learning
Authors: Mohamed Abdelfattah, Mariam Hassan, Alexandre Alahi
Date: 2024-01-01 00:00:00
Proceeding: CVPR 2024 1
Tasks: Action Recognition, Contrastive Learning, Representation Learning, Skeleton Based Action Recognition

    Current transformer-based skeletal action recognition models tend to focus on a limited set of joints and low-level motion patterns to predict action classes. This results in significant performance degradation under small skeleton perturbations or changing the pose estimator between training and testing. In this work we introduce MaskCLR a new Masked Contrastive Learning approach for Robust skeletal action recognition. We propose an Attention-Guided Probabilistic Masking strategy to occlude the most important joints and encourage the model to explore a larger set of discriminative joints. Furthermore we propose a Multi-Level Contrastive Learning paradigm to enforce the representations of standard and occluded skeletons to be class-discriminative i.e. more compact within each class and more dispersed across different classes. Our approach helps the model capture the high-level action semantics instead of low-level joint variations and can be conveniently incorporated into transformer-based models. Without loss of generality we combine MaskCLR with three transformer backbones: the vanilla transformer DSTFormer and STTFormer. Extensive experiments on NTU60 NTU120 and Kinetics400 show that MaskCLR consistently outperforms previous state-of-the-art methods on standard and perturbed skeletons from different pose estimators showing improved accuracy generalization and robustness. Project website: https://maskclr.github.io.
Dynamic Cues-Assisted Transformer for Robust Point Cloud Registration
Authors: Hong Chen, Pei Yan, Sihe Xiang, Yihua Tan
Date: 2024-01-01 00:00:00
Proceeding: CVPR 2024 1
Tasks: Point Cloud Registration

    Point Cloud Registration is a critical and challenging task in computer vision. Recent advancements have predominantly embraced a coarse-to-fine matching mechanism with the key to matching the superpoints located in patches with inter-frame consistent structures. However previous methods still face challenges with ambiguous matching because the interference information aggregated from irrelevant regions may disturb the capture of inter-frame consistency relations leading to wrong matches. To address this issue we propose Dynamic Cues-Assisted Transformer (DCATr). Firstly the interference from irrelevant regions is greatly reduced by constraining attention to certain cues i.e. regions with highly correlated structures of potential corresponding superpoints. Secondly cues-assisted attention is designed to mine the inter-frame consistency relations while more attention is assigned to pairs with high consistent confidence in feature aggregation. Finally a dynamic updating fashion is proposed to facilitate mining richer consistency information further improving aggregated features' distinctiveness and relieving matching ambiguity. Extensive evaluations on indoor and outdoor standard benchmarks demonstrate that DCATr outperforms all state-of-the-art methods.
SynSP: Synergy of Smoothness and Precision in Pose Sequences Refinement
Authors: Tao Wang, Lei Jin, Zheng Wang, Jianshu Li, Liang Li, Fang Zhao, Yu Cheng, Li Yuan, Li Zhou, Junliang Xing, Jian Zhao
Date: 2024-01-01 00:00:00
Proceeding: CVPR 2024 1

    Predicting human pose sequences via existing pose estimators often encounters various estimation errors. Motion refinement methods aim to optimize the predicted human pose sequences from pose estimators while ensuring minimal computational overhead and latency. Prior investigations have primarily concentrated on striking a balance between the two objectives i.e. smoothness and precision while optimizing the predicted pose sequences. However it has come to our attention that the tension between these two objectives can provide additional quality cues about the predicted pose sequences. These cues in turn are able to aid the network in optimizing lower-quality poses. To leverage this quality information we propose a motion refinement network termed SynSP to achieve a Synergy of Smoothness and Precision in the sequence refinement tasks. Moreover SynSP can also address multi-view poses of one person simultaneously fixing inaccuracies in predicted poses through heightened attention to similar poses from other views thereby amplifying the resultant quality cues and overall performance. Compared with previous methods SynSP benefits from both pose quality and multi-view information with a much shorter input sequence length achieving state-of-the-art results among four challenging datasets involving 2D 3D and SMPL pose representations in both single-view and multi-view scenes. Github code: https://github.com/InvertedForest/SynSP.
Diffusion Handles Enabling 3D Edits for Diffusion Models by Lifting Activations to 3D
Authors: Karran Pandey, Paul Guerrero, Matheus Gadelha, Yannick Hold-Geoffroy, Karan Singh, Niloy J. Mitra
Date: 2024-01-01 00:00:00
Proceeding: CVPR 2024 1
Tasks: 3D Object Retrieval, Depth Estimation, Object, Retrieval

    Diffusion handles is a novel approach to enable 3D object edits on diffusion images requiring only existing pre-trained diffusion models depth estimation without any fine-tuning or 3D object retrieval. The edited results remain plausible photo-real and preserve object identity. Diffusion handles address a critically missing facet of generative image-based creative design. Our key insight is to lift diffusion activations for a selected object to 3D using a proxy depth 3D-transform the depth and associated activations and project them back to image space. The diffusion process guided by the manipulated activations produces plausible edited images showing complex 3D occlusion and lighting effects. We evaluate diffusion handles: quantitatively on a large synthetic data benchmark; and qualitatively by a user study showing our output to be more plausible and better than prior art at both 3D editing and identity control.
GigaTraj: Predicting Long-term Trajectories of Hundreds of Pedestrians in Gigapixel Complex Scenes
Authors: Haozhe Lin, Chunyu Wei, Li He, Yuchen Guo, Yunqi Zhao, Shanglong Li, Lu Fang
Date: 2024-01-01 00:00:00
Proceeding: CVPR 2024 1
Tasks: Pedestrian Trajectory Prediction, Prediction, Trajectory Prediction

    Pedestrian trajectory prediction is a well-established task with significant recent advancements. However existing datasets are unable to fulfill the demand for studying minute-level long-term trajectory prediction mainly due to the lack of high-resolution trajectory observation in the wide field of view (FoV). To bridge this gap we introduce a novel dataset named GigaTraj featuring videos capturing a wide FoV with ~ 4 x10^4  m^2 and high-resolution imagery at the gigapixel level. Furthermore GigaTraj includes comprehensive annotations such as bounding boxes identity associations world coordinates group/interaction relationships and scene semantics. Leveraging these multimodal annotations we evaluate and validate the state-of-the-art approaches for minute-level long-term trajectory prediction in large-scale scenes. Extensive experiments and analyses have revealed that long-term prediction for pedestrian trajectories presents numerous challenges indicating a vital new direction for trajectory research. The dataset is available at www.gigavision.ai.
Learning from Synthetic Human Group Activities
Authors: Che-Jui Chang, Danrui Li, Deep Patel, Parth Goel, Honglu Zhou, Seonghyeon Moon, Samuel S. Sohn, Sejong Yoon, Vladimir Pavlovic, Mubbasir Kapadia
Date: 2024-01-01 00:00:00
Proceeding: CVPR 2024 1
Tasks: Unity

    The study of complex human interactions and group activities has become a focal point in human-centric computer vision. However progress in related tasks is often hindered by the challenges of obtaining large-scale labeled datasets from real-world scenarios. To address the limitation we introduce M3Act a synthetic data generator for multi-view multi-group multi-person human atomic actions and group activities. Powered by Unity Engine M3Act features multiple semantic groups highly diverse and photorealistic images and a comprehensive set of annotations which facilitates the learning of human-centered tasks across single-person multi-person and multi-group conditions. We demonstrate the advantages of M3Act across three core experiments. The results suggest our synthetic dataset can significantly improve the performance of several downstream methods and replace real-world datasets to reduce cost. Notably M3Act improves the state-of-the-art MOTRv2 on DanceTrack dataset leading to a hop on the leaderboard from 10th to 2nd place. Moreover M3Act opens new research for controllable 3D group activity generation. We define multiple metrics and propose a competitive baseline for the novel task. Our code and data are available at our project page: http://cjerry1243.github.io/M3Act.