GenAI4ELab/papercli-papers huggingface dataset:
Generalized Event Cameras
Authors: Varun Sundar; Matthew Dutson; Andrei Ardelean; Claudio Bruschini; Edoardo Charbon; Mohit Gupta
Venue: CVPR 2024 (main)

Abstract: Event cameras capture the world at high time resolution and with minimal bandwidth requirements. However event streams which only encode changes in brightness do not contain sufficient scene information to support a wide variety of downstream tasks. In this work we design generalized event cameras that inherently preserve scene intensity in a bandwidth-efficient manner. We generalize event cameras in terms of when an event is generated and what information is transmitted. To implement our designs we turn to single-photon sensors that provide digital access to individual photon detections; this modality gives us the flexibility to realize a rich space of generalized event cameras. Our single-photon event cameras are capable of high-speed high-fidelity imaging at low readout rates. Consequently these event cameras can support plug-and-play downstream inference without capturing new event datasets or designing specialized event-vision models. As a practical implication our designs which involve lightweight and near-sensor-compatible computations provide a way to use single-photon sensors without exorbitant bandwidth costs.
3D Neural Edge Reconstruction
Authors: Lei Li; Songyou Peng; Zehao Yu; Shaohui Liu; Rémi Pautrat; Xiaochuan Yin; Marc Pollefeys
Venue: CVPR 2024 (main)

Abstract: Real-world objects and environments are predominantly composed of edge features including straight lines and curves. Such edges are crucial elements for various applications such as CAD modeling surface meshing lane mapping etc. However existing traditional methods only prioritize lines over curves for simplicity in geometric modeling. To this end we introduce EMAP a new method for learning 3D edge representations with a focus on both lines and curves. Our method implicitly encodes 3D edge distance and direction in Unsigned Distance Functions (UDF) from multi-view edge maps. On top of this neural representation we propose an edge extraction algorithm that robustly abstracts parametric 3D edges from the inferred edge points and their directions. Comprehensive evaluations demonstrate that our method achieves better 3D edge reconstruction on multiple challenging datasets. We further show that our learned UDF field enhances neural surface reconstruction by capturing more details.
DocRes: A Generalist Model Toward Unifying Document Image Restoration Tasks
Authors: Jiaxin Zhang; Dezhi Peng; Chongyu Liu; Peirong Zhang; Lianwen Jin
Venue: CVPR 2024 (main)

Abstract: Document image restoration is a crucial aspect of Document AI systems as the quality of document images significantly influences the overall performance. Prevailing methods address distinct restoration tasks independently leading to intricate systems and the incapability to harness the potential synergies of multi-task learning. To overcome this challenge we propose DocRes a generalist model that unifies five document image restoration tasks including dewarping deshadowing appearance enhancement deblurring and binarization. To instruct DocRes to perform various restoration tasks we propose a novel visual prompt approach called Dynamic Task-Specific Prompt (DTSPrompt). The DTSPrompt for different tasks comprises distinct prior features which are additional characteristics extracted from the input image. Beyond its role as a cue for task-specific execution DTSPrompt can also serve as supplementary information to enhance the model's performance. Moreover DTSPrompt is more flexible than prior visual prompt approaches as it can be seamlessly applied and adapted to inputs with high and variable resolutions. Experimental results demonstrate that DocRes achieves competitive or superior performance compared to existing state-of-the-art task-specific models. This underscores the potential of DocRes across a broader spectrum of document image restoration tasks. The source code is publicly available at https://github.com/ZZZHANG-jx/DocRes.
Honeybee: Locality-enhanced Projector for Multimodal LLM
Authors: Junbum Cha; Wooyoung Kang; Jonghwan Mun; Byungseok Roh
Venue: CVPR 2024 (main)

Abstract: In Multimodal Large Language Models (MLLMs) a visual projector plays a crucial role in bridging pre-trained vision encoders with LLMs enabling profound visual understanding while harnessing the LLMs' robust capabilities. Despite the importance of the visual projector it has been relatively less explored. In this study we first identify two essential projector properties: (i) flexibility in managing the number of visual tokens crucial for MLLMs' overall efficiency and (ii) preservation of local context from visual features vital for spatial understanding. Based on these findings we propose a novel projector design that is both flexible and locality-enhanced effectively satisfying the two desirable properties. Additionally we present comprehensive strategies to effectively utilize multiple and multifaceted instruction datasets. Through extensive experiments we examine the impact of individual design choices. Finally our proposed MLLM Honeybee remarkably outperforms previous state-of-the-art methods across various benchmarks including MME MMBench SEED-Bench and LLaVA-Bench achieving significantly higher efficiency. Code and models are available at https://github.com/kakaobrain/honeybee.
Learned Trajectory Embedding for Subspace Clustering
Authors: Yaroslava Lochman; Carl Olsson; Christopher Zach
Venue: CVPR 2024 (main)

Abstract: Clustering multiple motions from observed point trajectories is a fundamental task in understanding dynamic scenes. Most motion models require multiple tracks to estimate their parameters hence identifying clusters when multiple motions are observed is a very challenging task. This is even aggravated for high-dimensional motion models. The starting point of our work is that this high-dimensionality of motion model can actually be leveraged to our advantage as sufficiently long trajectories identify the underlying motion uniquely in practice. Consequently we propose to learn a mapping from trajectories to embedding vectors that represent the generating motion. The obtained trajectory embeddings are useful for clustering multiple observed motions but are also trained to contain sufficient information to recover the parameters of the underlying motion by utilizing a geometric loss. We therefore are able to use only weak supervision from given motion segmentation to train this mapping. The entire algorithm consisting of trajectory embedding clustering and motion parameter estimation is highly efficient. We conduct experiments on the Hopkins155 Hopkins12 and KT3DMoSeg datasets and show state-of-the-art performance of our proposed method for trajectory-based motion segmentation on full sequences and its competitiveness on the occluded sequences. Project page: https://ylochman.github.io/trajectory-embedding.
Training Vision Transformers for Semi-Supervised Semantic Segmentation
Authors: Xinting Hu; Li Jiang; Bernt Schiele
Venue: CVPR 2024 (main)

Abstract: We present S4Former a novel approach to training Vision Transformers for Semi-Supervised Semantic Segmentation (S4). At its core S4Former employs a Vision Transformer within a classic teacher-student framework and then leverages three novel technical ingredients: PatchShuffle as a parameter-free perturbation technique Patch-Adaptive Self-Attention (PASA) as a fine-grained feature modulation method and the innovative Negative Class Ranking (NCR) regularization loss. Based on these regularization modules aligned with Transformer-specific characteristics across the image input feature and output dimensions S4Former exploits the Transformer's ability to capture and differentiate consistent global contextual information in unlabeled images. Overall S4Former not only defines a new state of the art in S4 but also maintains a streamlined and scalable architecture. Being readily compatible with existing frameworks S4Former achieves strong improvements (up to 4.9%) on benchmarks like Pascal VOC 2012 COCO and Cityscapes with varying numbers of labeled data. The code is at https://github.com/JoyHuYY1412/S4Former.
HarmonyView: Harmonizing Consistency and Diversity in One-Image-to-3D
Authors: Sangmin Woo; Byeongjun Park; Hyojun Go; Jin-Young Kim; Changick Kim
Venue: CVPR 2024 (main)

Abstract: Recent progress in single-image 3D generation highlights the importance of multi-view coherency leveraging 3D priors from large-scale diffusion models pretrained on Internet-scale images. However the aspect of novel-view diversity remains underexplored within the research landscape due to the ambiguity in converting a 2D image into 3D content where numerous potential shapes can emerge. Here we aim to address this research gap by simultaneously addressing both consistency and diversity. Yet striking a balance between these two aspects poses a considerable challenge due to their inherent trade-offs. This work introduces HarmonyView a simple yet effective diffusion sampling technique adept at decomposing two intricate aspects in single-image 3D generation: consistency and diversity. This approach paves the way for a more nuanced exploration of the two critical dimensions within the sampling process. Moreover we propose a new evaluation metric based on CLIP image and text encoders to comprehensively assess the diversity of the generated views which closely aligns with human evaluators' judgments. In experiments HarmonyView achieves a harmonious balance demonstrating a win-win scenario in both consistency and diversity.
DGC-GNN: Leveraging Geometry and Color Cues for Visual Descriptor-Free 2D-3D Matching
Authors: Shuzhe Wang; Juho Kannala; Daniel Barath
Venue: CVPR 2024 (main)

Abstract: Matching 2D keypoints in an image to a sparse 3D point cloud of the scene without requiring visual descriptors has garnered increased interest due to its low memory requirements inherent privacy preservation and reduced need for expensive 3D model maintenance compared to visual descriptor-based methods. However existing algorithms often compromise on performance resulting in a significant deterioration compared to their descriptor-based counterparts. In this paper we introduce DGC-GNN a novel algorithm that employs a global-to-local Graph Neural Network (GNN) that progressively exploits geometric and color cues to rep- resent keypoints thereby improving matching accuracy. Our procedure encodes both Euclidean and angular relations at a coarse level forming the geometric embedding to guide the point matching. We evaluate DGC-GNN on both indoor and outdoor datasets demonstrating that it not only doubles the accuracy of the state-of-the-art visual descriptor-free algorithm but also substantially narrows the performance gap between descriptor-based and descriptor free methods.
CuVLER: Enhanced Unsupervised Object Discoveries through Exhaustive Self-Supervised Transformers
Authors: Shahaf Arica; Or Rubin; Sapir Gershov; Shlomi Laufer
Venue: CVPR 2024 (main)

Abstract: In this paper we introduce VoteCut an innovative method for unsupervised object discovery that leverages feature representations from multiple self-supervised models. VoteCut employs normalized-cut based graph partitioning clustering and a pixel voting approach. Additionally We present CuVLER (Cut-Vote-and-LEaRn) a zero-shot model trained using pseudo-labels generated by VoteCut and a novel soft target loss to refine segmentation accuracy. Through rigorous evaluations across multiple datasets and several unsupervised setups our methods demonstrate significant improvements in comparison to previous state-of-the-art models. Our ablation studies further highlight the contributions of each component revealing the robustness and efficacy of our approach. Collectively VoteCut and CuVLER pave the way for future advancements in image segmentation.
Quantifying Task Priority for Multi-Task Optimization
Authors: Wooseong Jeong; Kuk-Jin Yoon
Venue: CVPR 2024 (main)

Abstract: The goal of multi-task learning is to learn diverse tasks within a single unified network. As each task has its own unique objective function conflicts emerge during training resulting in negative transfer among them. Earlier research identified these conflicting gradients in shared parameters between tasks and attempted to realign them in the same direction. However we prove that such optimization strategies lead to sub-optimal Pareto solutions due to their inability to accurately determine the individual contributions of each parameter across various tasks. In this paper we propose the concept of task priority to evaluate parameter contributions across different tasks. To learn task priority we identify the type of connections related to links between parameters influenced by task-specific losses during backpropagation. The strength of connections is gauged by the magnitude of parameters to determine task priority. Based on these we present a new method named connection strength-based optimization for multi-task learning which consists of two phases. The first phase learns the task priority within the network while the second phase modifies the gradients while upholding this priority. This ultimately leads to finding new Pareto optimal solutions for multiple tasks. Through extensive experiments we show that our approach greatly enhances multi-task performance in comparison to earlier gradient manipulation methods.
UnSAMFlow: Unsupervised Optical Flow Guided by Segment Anything Model
Authors: Shuai Yuan; Lei Luo; Zhuo Hui; Can Pu; Xiaoyu Xiang; Rakesh Ranjan; Denis Demandolx
Venue: CVPR 2024 (main)

Abstract: Traditional unsupervised optical flow methods are vulnerable to occlusions and motion boundaries due to lack of object-level information. Therefore we propose UnSAMFlow an unsupervised flow network that also leverages object information from the latest foundation model Segment Anything Model (SAM). We first include a self-supervised semantic augmentation module tailored to SAM masks. We also analyze the poor gradient landscapes of traditional smoothness losses and propose a new smoothness definition based on homography instead. A simple yet effective mask feature module has also been added to further aggregate features on the object level. With all these adaptations our method produces clear optical flow estimation with sharp boundaries around objects which outperforms state-of-the-art methods on both KITTI and Sintel datasets. Our method also generalizes well across domains and runs very efficiently.
Exploiting Inter-sample and Inter-feature Relations in Dataset Distillation
Authors: Wenxiao Deng; Wenbin Li; Tianyu Ding; Lei Wang; Hongguang Zhang; Kuihua Huang; Jing Huo; Yang Gao
Venue: CVPR 2024 (main)

Abstract: Dataset distillation has emerged as a promising approach in deep learning enabling efficient training with small synthetic datasets derived from larger real ones. Particularly distribution matching-based distillation methods attract attention thanks to its effectiveness and low computational cost. However these methods face two primary limitations: the dispersed feature distribution within the same class in synthetic datasets reducing class discrimination and an exclusive focus on mean feature consistency lacking precision and comprehensiveness. To address these challenges we introduce two novel constraints: a class centralization constraint and a covariance matching constraint. The class centralization constraint aims to enhance class discrimination by more closely clustering samples within classes. The covariance matching constraint seeks to achieve more accurate feature distribution matching between real and synthetic datasets through local feature covariance matrices particularly beneficial when sample sizes are much smaller than the number of features. Experiments demonstrate notable improvements with these constraints yielding performance boosts of up to 6.6% on CIFAR10 2.9% on SVHN 2.5% on CIFAR100 and 2.5% on TinyImageNet compared to the state-of-the-art relevant methods. In addition our method maintains robust performance in cross-architecture settings with a maximum performance drop of 1.7% on four architectures. Code is available at https://github.com/VincenDen/IID.
On the Scalability of Diffusion-based Text-to-Image Generation
Authors: Hao Li; Yang Zou; Ying Wang; Orchid Majumder; Yusheng Xie; R. Manmatha; Ashwin Swaminathan; Zhuowen Tu; Stefano Ermon; Stefano Soatto
Venue: CVPR 2024 (main)

Abstract: Scaling up model and data size has been quite successful for the evolution of LLMs. However the scaling law for the diffusion based text-to-image (T2I) models is not fully explored. It is also unclear how to efficiently scale the model for better performance at reduced cost. The different training settings and expensive training cost make a fair model comparison extremely difficult. In this work we empirically study the scaling properties of diffusion based T2I models by performing extensive and rigours ablations on scaling both denoising backbones and training set including training scaled UNet and Transformer variants ranging from 0.4B to 4B parameters on datasets upto 600M images. For model scaling we find the location and amount of cross attention distinguishes the performance of existing UNet designs. And increasing the transformer blocks is more parameter-efficient for improving text-image alignment than increasing channel numbers. We then identify an efficient UNet variant which is 45% smaller and 28% faster than SDXL's UNet. On the data scaling side we show the quality and diversity of the training set matters more than simply dataset size. Increasing caption density and diversity improves text-image alignment performance and the learning efficiency. Finally we provide scaling functions to predict the text-image alignment performance as functions of the scale of model size compute and dataset size.
Entity-NeRF: Detecting and Removing Moving Entities in Urban Scenes
Authors: Takashi Otonari; Satoshi Ikehata; Kiyoharu Aizawa
Venue: CVPR 2024 (main)

Abstract: Recent advancements in the study of Neural Radiance Fields (NeRF) for dynamic scenes often involve explicit modeling of scene dynamics. However this approach faces challenges in modeling scene dynamics in urban environments where moving objects of various categories and scales are present. In such settings it becomes crucial to effectively eliminate moving objects to accurately reconstruct static backgrounds. Our research introduces an innovative method termed here as Entity-NeRF which combines the strengths of knowledge-based and statistical strategies. This approach utilizes entity-wise statistics leveraging entity segmentation and stationary entity classification through thing/stuff segmentation. To assess our methodology we created an urban scene dataset masked with moving objects. Our comprehensive experiments demonstrate that Entity-NeRF notably outperforms existing techniques in removing moving objects and reconstructing static urban backgrounds both quantitatively and qualitatively.
TAMM: TriAdapter Multi-Modal Learning for 3D Shape Understanding
Authors: Zhihao Zhang; Shengcao Cao; Yu-Xiong Wang
Venue: CVPR 2024 (main)

Abstract: The limited scale of current 3D shape datasets hinders the advancements in 3D shape understanding and motivates multi-modal learning approaches which transfer learned knowledge from data-abundant 2D image and language modalities to 3D shapes. However even though the image and language representations have been aligned by cross-modal models like CLIP we find that the image modality fails to contribute as much as the language in existing multi-modal 3D representation learning methods. This is attributed to the domain shift in the 2D images and the distinct focus of each modality. To more effectively leverage both modalities in the pre-training we introduce TriAdapter Multi-Modal Learning (TAMM) - a novel two-stage learning approach based on three synergistic adapters. First our CLIP Image Adapter mitigates the domain gap between 3D-rendered images and natural images by adapting the visual representations of CLIP for synthetic image-text pairs. Subsequently our Dual Adapters decouple the 3D shape representation space into two complementary sub-spaces: one focusing on visual attributes and the other for semantic understanding which ensure a more comprehensive and effective multi-modal pre-training. Extensive experiments demonstrate that TAMM consistently enhances 3D representations for a wide range of 3D encoder architectures pre-training datasets and downstream tasks. Notably we boost the zero-shot classification accuracy on Objaverse-LVIS from 46.8% to 50.7% and improve the 5-way 10-shot linear probing classification accuracy on ModelNet40 from 96.1% to 99.0%. Project page: https://alanzhangcs.github.io/tamm-page.
GauHuman: Articulated Gaussian Splatting from Monocular Human Videos
Authors: Shoukang Hu; Tao Hu; Ziwei Liu
Venue: CVPR 2024 (main)

Abstract: We present GauHuman a 3D human model with Gaussian Splatting for both fast training (1 2 minutes) and real-time rendering (up to 189 FPS) compared with existing NeRF-based implicit representation modelling frameworks demanding hours of training and seconds of rendering per frame. Specifically GauHuman encodes Gaussian Splatting in the canonical space and transforms 3D Gaussians from canonical space to posed space with linear blend skinning (LBS) in which effective pose and LBS refinement modules are designed to learn fine details of 3D humans under negligible computational cost. Moreover to enable fast optimization of GauHuman we initialize and prune 3D Gaussians with 3D human prior while splitting/cloning via KL divergence guidance along with a novel merge operation for further speeding up. Extensive experiments on ZJU_Mocap and MonoCap datasets demonstrate that GauHuman achieves state-of-the-art performance quantitatively and qualitatively with fast training and real-time rendering speed. Notably without sacrificing rendering quality GauHuman can fast model the 3D human performer with  13k 3D Gaussians. Our code is available at https://github.com/skhu101/GauHuman.
AnySkill: Learning Open-Vocabulary Physical Skill for Interactive Agents
Authors: Jieming Cui; Tengyu Liu; Nian Liu; Yaodong Yang; Yixin Zhu; Siyuan Huang
Venue: CVPR 2024 (main)

Abstract: Traditional approaches in physics-based motion generation centered around imitation learning and reward shaping often struggle to adapt to new scenarios. To tackle this limitation we propose AnySkill a novel hierarchical method that learns physically plausible interactions following open-vocabulary instructions. Our approach begins by developing a set of atomic actions via a low-level controller trained via imitation learning. Upon receiving an open-vocabulary textual instruction AnySkill employs a high-level policy that selects and integrates these atomic actions to maximize the CLIP similarity between the agent's rendered images and the text. An important feature of our method is the use of image-based rewards for the high-level policy which allows the agent to learn interactions with objects without manual reward engineering. We demonstrate AnySkill's capability to generate realistic and natural motion sequences in response to unseen instructions of varying lengths marking it the first method capable of open-vocabulary physical skill learning for interactive humanoid agents.