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CVPR2024

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CVPR2024-papers

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SDPose: Tokenized Pose Estimation via Circulation-Guide Self-Distillation

http://arxiv.org/abs/2404.03518

Sichen Chen, Yingyi Zhang, Siming Huang, Ran Yi, Ke Fan, Ruixin Zhang, Peixian Chen, Jun Wang, Shouhong Ding, Lizhuang Ma

Recently transformer-based methods have achieved state-of-the-art prediction quality on human pose estimation(HPE). Nonetheless most of these top-performing transformer-based models are too computation-consuming and storage-demanding to deploy on edge computing platforms. Those transformer-based models that require fewer resources are prone to under-fitting due to their smaller scale and thus perform notably worse than their larger counterparts. Given this conundrum we introduce SDPose a new self-distillation method for improving the performance of small transformer-based models. To mitigate the problem of under-fitting we design a transformer module named Multi-Cycled Transformer(MCT) based on multiple-cycled forwards to more fully exploit the potential of small model parameters. Further in order to prevent the additional inference compute-consuming brought by MCT we introduce a self-distillation scheme extracting the knowledge from the MCT module to a naive forward model. Specifically on the MSCOCO validation dataset SDPose-T obtains 69.7% mAP with 4.4M parameters and 1.8 GFLOPs. Furthermore SDPose-S-V2 obtains 73.5% mAP on the MSCOCO validation dataset with 6.2M parameters and 4.7 GFLOPs achieving a new state-of-the-art among predominant tiny neural network methods.

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Authentic Hand Avatar from a Phone Scan via Universal Hand Model

http://arxiv.org/abs/2405.07933

Gyeongsik Moon, Weipeng Xu, Rohan Joshi, Chenglei Wu, Takaaki Shiratori

The authentic 3D hand avatar with every identifiable information such as hand shapes and textures is necessary for immersive experiences in AR/VR. In this paper we present a universal hand model (UHM) which 1) can universally represent high-fidelity 3D hand meshes of arbitrary identities (IDs) and 2) can be adapted to each person with a short phone scan for the authentic hand avatar. For effective universal hand modeling we perform tracking and modeling at the same time while previous 3D hand models perform them separately. The conventional separate pipeline suffers from the accumulated errors from the tracking stage which cannot be recovered in the modeling stage. On the other hand ours does not suffer from the accumulated errors while having a much more concise overall pipeline. We additionally introduce a novel image matching loss function to address a skin sliding during the tracking and modeling while existing works have not focused on it much. Finally using learned priors from our UHM we effectively adapt our UHM to each person's short phone scan for the authentic hand avatar.

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VCoder: Versatile Vision Encoders for Multimodal Large Language Models

http://arxiv.org/abs/2312.14233

Jitesh Jain, Jianwei Yang, Humphrey Shi

Humans possess the remarkable skill of Visual Perception the ability to see and understand the seen helping them make sense of the visual world and in turn reason. Multimodal Large Language Models (MLLM) have recently achieved impressive performance on vision-language tasks ranging from visual question-answering and image captioning to visual reasoning and image generation. However when prompted to identify or count (perceive) the entities in a given image existing MLLM systems fail. Working towards developing an accurate MLLM system for perception and reasoning we propose using Versatile vision enCoders (VCoder) as perception eyes for Multimodal LLMs. We feed the VCoder with perception modalities such as segmentation or depth maps improving the MLLM's perception abilities. Secondly we leverage the images from COCO and outputs from off-the-shelf vision perception models to create our COCO Segmentation Text (COST) dataset for training and evaluating MLLMs on the object perception task. Thirdly we introduce metrics to assess the object perception abilities in MLLMs on our COST dataset. Lastly we provide extensive experimental evidence proving the VCoder's improved object-level perception skills over existing Multimodal LLMs including GPT-4V. We open-source our dataset code and models to promote research.

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Event-based Visible and Infrared Fusion via Multi-task Collaboration

Mengyue Geng, Lin Zhu, Lizhi Wang, Wei Zhang, Ruiqin Xiong, Yonghong Tian

Visible and Infrared image Fusion (VIF) offers a comprehensive scene description by combining thermal infrared images with the rich textures from visible cameras. However conventional VIF systems may capture over/under exposure or blurry images in extreme lighting and high dynamic motion scenarios leading to degraded fusion results. To address these problems we propose a novel Event-based Visible and Infrared Fusion (EVIF) system that employs a visible event camera as an alternative to traditional frame-based cameras for the VIF task. With extremely low latency and high dynamic range event cameras can effectively address blurriness and are robust against diverse luminous ranges. To produce high-quality fused images we develop a multi-task collaborative framework that simultaneously performs event-based visible texture reconstruction event-guided infrared image deblurring and visible-infrared fusion. Rather than independently learning these tasks our framework capitalizes on their synergy leveraging cross-task event enhancement for efficient deblurring and bi-level min-max mutual information optimization to achieve higher fusion quality. Experiments on both synthetic and real data show that EVIF achieves remarkable performance in dealing with extreme lighting conditions and high-dynamic scenes ensuring high-quality fused images across a broad range of practical scenarios.

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Open-World Semantic Segmentation Including Class Similarity

http://arxiv.org/abs/2403.07532

Matteo Sodano, Federico Magistri, Lucas Nunes, Jens Behley, Cyrill Stachniss

Interpreting camera data is key for autonomously acting systems such as autonomous vehicles. Vision systems that operate in real-world environments must be able to understand their surroundings and need the ability to deal with novel situations. This paper tackles open-world semantic segmentation i.e. the variant of interpreting image data in which objects occur that have not been seen during training. We propose a novel approach that performs accurate closed-world semantic segmentation and at the same time can identify new categories without requiring any additional training data. Our approach additionally provides a similarity measure for every newly discovered class in an image to a known category which can be useful information in downstream tasks such as planning or mapping. Through extensive experiments we show that our model achieves state-of-the-art results on classes known from training data as well as for anomaly segmentation and can distinguish between different unknown classes.

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RegionPLC: Regional Point-Language Contrastive Learning for Open-World 3D Scene Understanding

http://arxiv.org/abs/2304.00962

Jihan Yang, Runyu Ding, Weipeng Deng, Zhe Wang, Xiaojuan Qi

We propose a lightweight and scalable Regional Point-Language Contrastive learning framework namely RegionPLC for open-world 3D scene understanding aiming to identify and recognize open-set objects and categories. Specifically based on our empirical studies we introduce a 3D-aware SFusion strategy that fuses 3D vision-language pairs derived from multiple 2D foundation models yielding high-quality dense region-level language descriptions without human 3D annotations. Subsequently we devise a region-aware point-discriminative contrastive learning objective to enable robust and effective 3D learning from dense regional language supervision. We carry out extensive experiments on ScanNet ScanNet200 and nuScenes datasets and our model outperforms prior 3D open-world scene understanding approaches by an average of 17.2% and 9.1% for semantic and instance segmentation respectively while maintaining greater scalability and lower resource demands. Furthermore our method has the flexibility to be effortlessly integrated with language models to enable open-ended grounded 3D reasoning without extra task-specific training. Code will be released.

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Adaptive VIO: Deep Visual-Inertial Odometry with Online Continual Learning

http://arxiv.org/abs/2405.16754

Youqi Pan, Wugen Zhou, Yingdian Cao, Hongbin Zha

Visual-inertial odometry (VIO) has demonstrated remarkable success due to its low-cost and complementary sensors. However existing VIO methods lack the generalization ability to adjust to different environments and sensor attributes. In this paper we propose Adaptive VIO a new monocular visual-inertial odometry that combines online continual learning with traditional nonlinear optimization. Adaptive VIO comprises two networks to predict visual correspondence and IMU bias. Unlike end-to-end approaches that use networks to fuse the features from two modalities (camera and IMU) and predict poses directly we combine neural networks with visual-inertial bundle adjustment in our VIO system. The optimized estimates will be fed back to the visual and IMU bias networks refining the networks in a self-supervised manner. Such a learning-optimization-combined framework and feedback mechanism enable the system to perform online continual learning. Experiments demonstrate that our Adaptive VIO manifests adaptive capability on EuRoC and TUM-VI datasets. The overall performance exceeds the currently known learning-based VIO methods and is comparable to the state-of-the-art optimization-based methods.

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Towards Memorization-Free Diffusion Models

http://arxiv.org/abs/2404.00922

Chen Chen, Daochang Liu, Chang Xu

Pretrained diffusion models and their outputs are widely accessible due to their exceptional capacity for synthesizing high-quality images and their open-source nature. The users however may face litigation risks owing to the models' tendency to memorize and regurgitate training data during inference. To address this we introduce Anti-Memorization Guidance (AMG) a novel framework employing three targeted guidance strategies for the main causes of memorization: image and caption duplication and highly specific user prompts. Consequently AMG ensures memorization-free outputs while maintaining high image quality and text alignment leveraging the synergy of its guidance methods each indispensable in its own right. AMG also features an innovative automatic detection system for potential memorization during each step of inference process allows selective application of guidance strategies minimally interfering with the original sampling process to preserve output utility. We applied AMG to pretrained Denoising Diffusion Probabilistic Models (DDPM) and Stable Diffusion across various generation tasks. The results demonstrate that AMG is the first approach to successfully eradicates all instances of memorization with no or marginal impacts on image quality and text-alignment as evidenced by FID and CLIP scores.

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Generalized Large-Scale Data Condensation via Various Backbone and Statistical Matching

http://arxiv.org/abs/2311.17950

Shitong Shao, Zeyuan Yin, Muxin Zhou, Xindong Zhang, Zhiqiang Shen

The lightweight "local-match-global" matching introduced by SRe2L successfully creates a distilled dataset with comprehensive information on the full 224x224 ImageNet-1k. However this one-sided approach is limited to a particular backbone layer and statistics which limits the improvement of the generalization of a distilled dataset. We suggest that sufficient and various "local-match-global" matching are more precise and effective than a single one and has the ability to create a distilled dataset with richer information and better generalization. We call this perspective "generalized matching" and propose Generalized Various Backbone and Statistical Matching (G-VBSM) in this work which aims to create a synthetic dataset with densities ensuring consistency with the complete dataset across various backbones layers and statistics. As experimentally demonstrated G-VBSM is the first algorithm to obtain strong performance across both small-scale and large-scale datasets. Specifically G-VBSM achieves a performance of 38.7% on CIFAR-100 with 128-width ConvNet 47.6% on Tiny-ImageNet with ResNet18 and 31.4% on the full 224x224 ImageNet-1k with ResNet18 under images per class (IPC) 10 50 and 10 respectively. These results surpass all SOTA methods by margins of 3.9% 6.5% and 10.1% respectively.

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Three Pillars Improving Vision Foundation Model Distillation for Lidar

http://arxiv.org/abs/2310.17504

Gilles Puy, Spyros Gidaris, Alexandre Boulch, Oriane Siméoni, Corentin Sautier, Patrick Pérez, Andrei Bursuc, Renaud Marlet

Self-supervised image backbones can be used to address complex 2D tasks (e.g. semantic segmentation object discovery) very efficiently and with little or no downstream supervision. Ideally 3D backbones for lidar should be able to inherit these properties after distillation of these powerful 2D features. The most recent methods for image-to-lidar distillation on autonomous driving data show promising results obtained thanks to distillation methods that keep improving. Yet we still notice a large performance gap when measuring by linear probing the quality of distilled vs fully supervised features. In this work instead of focusing only on the distillation method we study the effect of three pillars for distillation: the 3D backbone the pretrained 2D backbone and the pretraining 2D+3D dataset. In particular thanks to our scalable distillation method named ScaLR we show that scaling the 2D and 3D backbones and pretraining on diverse datasets leads to a substantial improvement of the feature quality. This allows us to significantly reduce the gap between the quality of distilled and fully-supervised 3D features and to improve the robustness of the pretrained backbones to domain gaps and perturbations.

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On Train-Test Class Overlap and Detection for Image Retrieval

http://arxiv.org/abs/2404.01524

Chull Hwan Song, Jooyoung Yoon, Taebaek Hwang, Shunghyun Choi, Yeong Hyeon Gu, Yannis Avrithis

How important is it for training and evaluation sets to not have class overlap in image retrieval? We revisit Google Landmarks v2 clean the most popular training set by identifying and removing class overlap with Revisited Oxford and Paris the most popular training set. By comparing the original and the new RGLDv2-clean on a benchmark of reproduced state-of-the-art methods our findings are striking. Not only is there a dramatic drop in performance but it is inconsistent across methods changing the ranking. What does it take to focus on objects or interest and ignore background clutter when indexing? Do we need to analyze the evaluation set? Do we need to train an object detector and the representation separately? Do we need location supervision? We introduce Single-stage Detect-to-Retrieve (CiDeR) an end-to-end single-stage pipeline to detect objects of interest and extract a global image representation. We outperform previous state-of-the-art on both existing training sets and the new RGLDv2-clean.

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AttriHuman-3D: Editable 3D Human Avatar Generation with Attribute Decomposition and Indexing

Fan Yang, Tianyi Chen, Xiaosheng He, Zhongang Cai, Lei Yang, Si Wu, Guosheng Lin

Editable 3D-aware generation which supports user-interacted editing has witnessed rapid development recently. However existing editable 3D GANs either fail to achieve high-accuracy local editing or suffer from huge computational costs. We propose AttriHuman-3D an editable 3D human generation model which address the aforementioned problems with attribute decomposition and indexing. The core idea of the proposed model is to generate all attributes (e.g. human body hair clothes and so on) in an overall attribute space with six feature planes which are then decomposed and manipulated with different attribute indexes. To precisely extract features of different attributes from the generated feature planes we propose a novel attribute indexing method as well as an orthogonal projection regularization to enhance the disentanglement. We also introduce a hyper-latent training strategy and an attribute-specific sampling strategy to avoid style entanglement and misleading punishment from the discriminator. Our method allows users to interactively edit selected attributes in the generated 3D human avatars while keeping others fixed. Both qualitative and quantitative experiments demonstrate that our model provides a strong disentanglement between different attributes allows fine-grained image editing and generates high-quality 3D human avatars.

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IQ-VFI: Implicit Quadratic Motion Estimation for Video Frame Interpolation

Mengshun Hu, Kui Jiang, Zhihang Zhong, Zheng Wang, Yinqiang Zheng

Advanced video frame interpolation (VFI) algorithms approximate intermediate motions between two input frames to synthesize intermediate frame. However they struggle to handle complex scenarios with curvilinear motions since they overlook the latent acceleration information between the input frames. Moreover the supervision of predicted motions is tricky because ground-truth motions are not available. To this end we propose a novel framework for implicit quadratic video frame interpolation (IQ-VFI) which explores latent acceleration information and accurate intermediate motions via knowledge distillation. Specifically the proposed IQ-VFI consists of an implicit acceleration estimation network (IANet) and a VFI backbone the former fully leverages spatio-temporal information to explore latent acceleration priors between two input frames which is then used to progressively modulate linear motions from the latter into quadratic motions in coarse-to-fine manner. Furthermore to encourage both components to distill more acceleration and motion cues oriented towards VFI we propose a knowledge distillation strategy in which implicit acceleration distillation loss and implicit motion distillation loss are employed to adaptively guide latent acceleration priors and intermediate motions learning respectively. Extensive experiments show that our proposed IQ-VFI can achieve state-of-the-art performances on various benchmark datasets.

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KeyPoint Relative Position Encoding for Face Recognition

http://arxiv.org/abs/2403.14852

Minchul Kim, Yiyang Su, Feng Liu, Anil Jain, Xiaoming Liu

In this paper we address the challenge of making ViT models more robust to unseen affine transformations. Such robustness becomes useful in various recognition tasks such as face recognition when image alignment failures occur. We propose a novel method called KP-RPE which leverages key points (e.g.facial landmarks) to make ViT more resilient to scale translation and pose variations. We begin with the observation that Relative Position Encoding (RPE) is a good way to bring affine transform generalization to ViTs. RPE however can only inject the model with prior knowledge that nearby pixels are more important than far pixels. Keypoint RPE (KP-RPE) is an extension of this principle where the significance of pixels is not solely dictated by their proximity but also by their relative positions to specific keypoints within the image. By anchoring the significance of pixels around keypoints the model can more effectively retain spatial relationships even when those relationships are disrupted by affine transformations. We show the merit of KP-RPE in face and gait recognition. The experimental results demonstrate the effectiveness in improving face recognition performance from low-quality images particularly where alignment is prone to failure. Code and pre-trained models are available.

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Hyper-MD: Mesh Denoising with Customized Parameters Aware of Noise Intensity and Geometric Characteristics

Xingtao Wang, Hongliang Wei, Xiaopeng Fan, Debin Zhao

Mesh denoising (MD) is a critical task in geometry processing as meshes from scanning or AIGC techniques are susceptible to noise contamination. The challenge of MD lies in the diverse nature of mesh facets in terms of geometric characteristics and noise distributions. Despite recent advancements in deep learning-based MD methods existing MD networks typically neglect the consideration of geometric characteristics and noise distributions. In this paper we propose Hyper-MD a hyper-network-based approach that addresses this limitation by dynamically customizing denoising parameters for each facet based on its noise intensity and geometric characteristics. Specifically Hyper-MD is composed of a hyper-network and an MD network. For each noisy facet the hyper-network takes two angles as input to customize parameters for the MD network. These two angles are specially defined to reveal the noise intensity and geometric characteristics of the current facet respectively. The MD network receives a facet patch as input and outputs the denoised normal using the customized parameters. Experimental results on synthetic and real-scanned meshes demonstrate that Hyper-MD outperforms state-of-the-art mesh denoising methods.

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Learning Object State Changes in Videos: An Open-World Perspective

http://arxiv.org/abs/2312.11782

Zihui Xue, Kumar Ashutosh, Kristen Grauman

Object State Changes (OSCs) are pivotal for video understanding. While humans can effortlessly generalize OSC understanding from familiar to unknown objects current approaches are confined to a closed vocabulary. Addressing this gap we introduce a novel open-world formulation for the video OSC problem. The goal is to temporally localize the three stages of an OSC---the object's initial state its transitioning state and its end state---whether or not the object has been observed during training. Towards this end we develop VidOSC a holistic learning approach that: (1) leverages text and vision-language models for supervisory signals to obviate manually labeling OSC training data and (2) abstracts fine-grained shared state representations from objects to enhance generalization. Furthermore we present HowToChange the first open-world benchmark for video OSC localization which offers an order of magnitude increase in the label space and annotation volume compared to the best existing benchmark. Experimental results demonstrate the efficacy of our approach in both traditional closed-world and open-world scenarios.

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Beyond First-Order Tweedie: Solving Inverse Problems using Latent Diffusion

http://arxiv.org/abs/2312.00852

Litu Rout, Yujia Chen, Abhishek Kumar, Constantine Caramanis, Sanjay Shakkottai, Wen-Sheng Chu

Sampling from the posterior distribution in latent diffusion models for inverse problems is computationally challenging. Existing methods often rely on Tweedie's first-order moments that tend to induce biased results. Second-order approximations are computationally prohibitive making standard reverse diffusion processes intractable for posterior sampling. This paper presents Second-order Tweedie sampler from Surrogate Loss (STSL) a novel sampler offering efficiency comparable to first-order Tweedie while enabling tractable reverse processes using second-order approximation. Theoretical results reveal that our approach utilizing for the trace of the Hessian with only O(1) compute establishes a lower bound through a surrogate loss and enables a tractable reverse process. We show STSL outperforms SoTA solvers PSLD and P2L by reducing neural function evaluations by 4X and 8X respectively while enhancing sampling quality on FFHQ ImageNet and COCO benchmarks. Moreover STSL extends to text guided image editing and mitigates residual distortions in corrupted images. To our best knowledge this is the first work to offer an efficient second order approximation for solving inverse problems using latent diffusion and editing real world images with corruptions.

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Rethinking the Objectives of Vector-Quantized Tokenizers for Image Synthesis

http://arxiv.org/abs/2212.03185

Yuchao Gu, Xintao Wang, Yixiao Ge, Ying Shan, Mike Zheng Shou

Vector-Quantized (VQ-based) generative models usually consist of two basic components i.e. VQ tokenizers and generative transformers. Prior research focuses on improving the reconstruction fidelity of VQ tokenizers but rarely examines how the improvement in reconstruction affects the generation ability of generative transformers. In this paper we find that improving the reconstruction fidelity of VQ tokenizers does not necessarily improve the generation. Instead learning to compress semantic features within VQ tokenizers significantly improves generative transformers' ability to capture textures and structures. We thus highlight two competing objectives of VQ tokenizers for image synthesis: semantic compression and details preservation. Different from previous work that prioritizes better details preservation we propose Semantic-Quantized GAN (SeQ-GAN) with two learning phases to balance the two objectives. In the first phase we propose a semantic-enhanced perceptual loss for better semantic compression. In the second phase we fix the encoder and codebook but finetune the decoder to achieve better details preservation. Our proposed SeQ-GAN significantly improves VQ-based generative models for both unconditional and conditional image generation. Specifically SeQ-GAN achieves a Frechet Inception Distance (FID) of 6.25 and Inception Score (IS) of 140.9 on 256x256 ImageNet generation a remarkable improvement over VIT-VQGAN which obtains 11.2 FID and 97.2 IS.

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ShapeWalk: Compositional Shape Editing Through Language-Guided Chains

Habib Slim, Mohamed Elhoseiny

Editing 3D shapes through natural language instructions is a challenging task that requires the comprehension of both language semantics and fine-grained geometric details. To bridge this gap we introduce ShapeWalk a carefully designed synthetic dataset designed to advance the field of language-guided shape editing. The dataset consists of 158K unique shapes connected through 26K edit chains with an average length of 14 chained shapes. Each consecutive pair of shapes is associated with precise language instructions describing the applied edits. We synthesize edit chains by reconstructing and interpolating shapes sampled from a realistic CAD-designed 3D dataset in the parameter space of the GeoCode shape program. We leverage rule-based methods and language models to generate accurate and realistic natural language prompts corresponding to each edit. To illustrate the practicality of our contribution we train neural editor modules in the latent space of shape autoencoders and demonstrate the ability of our dataset to enable a variety of language-guided shape edits. Finally we introduce multi-step editing metrics to benchmark the capacity of our models to perform recursive shape edits. We hope that our work will enable further study of compositional language-guided shape editing and finds application in 3D CAD design and interactive modeling.

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MESA: Matching Everything by Segmenting Anything

http://arxiv.org/abs/2401.16741

Yesheng Zhang, Xu Zhao

Feature matching is a crucial task in the field of computer vision which involves finding correspondences between images. Previous studies achieve remarkable performance using learning-based feature comparison. However the pervasive presence of matching redundancy between images gives rise to unnecessary and error-prone computations in these methods imposing limitations on their accuracy. To address this issue we propose MESA a novel approach to establish precise area (or region) matches for efficient matching redundancy reduction. MESA first leverages the advanced image understanding capability of SAM a state-of-the-art foundation model for image segmentation to obtain image areas with implicit semantic. Then a multi-relational graph is proposed to model the spatial structure of these areas and construct their scale hierarchy. Based on graphical models derived from the graph the area matching is reformulated as an energy minimization task and effectively resolved. Extensive experiments demonstrate that MESA yields substantial precision improvement for multiple point matchers in indoor and outdoor downstream tasks e.g. +13.61% for DKM in indoor pose estimation.

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Learning Degradation-Independent Representations for Camera ISP Pipelines

http://arxiv.org/abs/2307.00761

Yanhui Guo, Fangzhou Luo, Xiaolin Wu

Image signal processing (ISP) pipeline plays a fundamental role in digital cameras which converts raw Bayer sensor data to RGB images. However ISP-generated images usually suffer from imperfections due to the compounded degradations that stem from sensor noises demosaicing noises compression artifacts and possibly adverse effects of erroneous ISP hyperparameter settings such as ISO and gamma values. In a general sense these ISP imperfections can be considered as degradations. The highly complex mechanisms of ISP degradations some of which are even unknown pose great challenges to the generalization capability of deep neural networks (DNN) for image restoration and to their adaptability to downstream tasks. To tackle the issues we propose a novel DNN approach to learn degradation-independent representations (DiR) through the refinement of a self-supervised learned baseline representation. The proposed DiR learning technique has remarkable domain generalization capability and consequently it outperforms state-of-the-art methods across various downstream tasks including blind image restoration object detection and instance segmentation as verified in our experiments.

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SCoFT: Self-Contrastive Fine-Tuning for Equitable Image Generation

http://arxiv.org/abs/2401.08053

Zhixuan Liu, Peter Schaldenbrand, Beverley-Claire Okogwu, Wenxuan Peng, Youngsik Yun, Andrew Hundt, Jihie Kim, Jean Oh

Accurate representation in media is known to improve the well-being of the people who consume it. Generative image models trained on large web-crawled datasets such as LAION are known to produce images with harmful stereotypes and misrepresentations of cultures. We improve inclusive representation in generated images by (1) engaging with communities to collect a culturally representative dataset that we call the Cross-Cultural Understanding Benchmark (CCUB) and (2) proposing a novel Self-Contrastive Fine-Tuning (SCoFT pronounced /soft/) method that leverages the model's known biases to self-improve. SCoFT is designed to prevent overfitting on small datasets encode only high-level information from the data and shift the generated distribution away from misrepresentations encoded in a pretrained model. Our user study conducted on 51 participants from 5 different countries based on their self-selected national cultural affiliation shows that fine-tuning on CCUB consistently generates images with higher cultural relevance and fewer stereotypes when compared to the Stable Diffusion baseline which is further improved with our SCoFT technique.

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Continuous Pose for Monocular Cameras in Neural Implicit Representation

http://arxiv.org/abs/2311.17119

Qi Ma, Danda Pani Paudel, Ajad Chhatkuli, Luc Van Gool

In this paper we showcase the effectiveness of optimizing monocular camera poses as a continuous function of time. The camera poses are represented using an implicit neural function which maps the given time to the corresponding camera pose. The mapped camera poses are then used for the downstream tasks where joint camera pose optimization is also required. While doing so the network parameters - that implicitly represent camera poses - are optimized. We exploit the proposed method in four diverse experimental settings namely (1) NeRF from noisy poses; (2) NeRF from asynchronous Events; (3) Visual Simultaneous Localization and Mapping (vSLAM); and (4) vSLAM with IMUs. In all four settings the proposed method performs significantly better than the compared baselines and the state-of-the-art methods. Additionally using the assumption of continuous motion changes in pose may actually live in a manifold that has lower than 6 degrees of freedom (DOF) is also realized. We call this low DOF motion representation as the intrinsic motion and use the approach in vSLAM settings show ing impressive camera tracking performance.

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OmniGlue: Generalizable Feature Matching with Foundation Model Guidance

http://arxiv.org/abs/2405.12979

Hanwen Jiang, Arjun Karpur, Bingyi Cao, Qixing Huang, André Araujo

The image matching field has been witnessing a continuous emergence of novel learnable feature matching techniques with ever-improving performance on conventional benchmarks. However our investigation shows that despite these gains their potential for real-world applications is restricted by their limited generalization capabilities to novel image domains. In this paper we introduce OmniGlue the first learnable image matcher that is designed with generalization as a core principle. OmniGlue leverages broad knowledge from a vision foundation model to guide the feature matching process boosting generalization to domains not seen at training time. Additionally we propose a novel keypoint position-guided attention mechanism which disentangles spatial and appearance information leading to enhanced matching descriptors. We perform comprehensive experiments on a suite of 6 datasets with varied image domains including scene-level object-centric and aerial images. OmniGlue's novel components lead to relative gains on unseen domains of 20.9% with respect to a directly comparable reference model while also outperforming the recent LightGlue method by 9.5% relatively. Code and model can be found at https://hwjiang1510.github.io/OmniGlue.

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D^4: Dataset Distillation via Disentangled Diffusion Model

Duo Su, Junjie Hou, Weizhi Gao, Yingjie Tian, Bowen Tang

Dataset distillation offers a lightweight synthetic dataset for fast network training with promising test accuracy. To imitate the performance of the original dataset most approaches employ bi-level optimization and the distillation space relies on the matching architecture. Nevertheless these approaches either suffer significant computational costs on large-scale datasets or experience performance decline on cross-architectures. We advocate for designing an economical dataset distillation framework that is independent of the matching architectures.With empirical observations we argue that constraining the consistency of the real and synthetic image spaces will enhance the cross-architecture generalization. Motivated by this we introduce Dataset Distillation via Disentangled Diffusion Model (D^4M) an efficient framework for dataset distillation. Compared to architecture-dependent methods D^4M employs latent diffusion model to guarantee consistency and incorporates label information into category prototypes. The distilled datasets are versatile eliminating the need for repeated generation of distinct datasets for various architectures. Through comprehensive experiments D^4M demonstrates superior performance and robust generalization surpassing the SOTA methods across most aspects.

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OmniSDF: Scene Reconstruction using Omnidirectional Signed Distance Functions and Adaptive Binoctrees

http://arxiv.org/abs/2404.00678

Hakyeong Kim, Andreas Meuleman, Hyeonjoong Jang, James Tompkin, Min H. Kim

We present a method to reconstruct indoor and outdoor static scene geometry and appearance from an omnidirectional video moving in a small circular sweep. This setting is challenging because of the small baseline and large depth ranges making it difficult to find ray crossings. To better constrain the optimization we estimate geometry as a signed distance field within a spherical binoctree data structure and use a complementary efficient tree traversal strategy based on a breadth-first search for sampling. Unlike regular grids or trees the shape of this structure well-matches the camera setting creating a better memory-quality trade-off. From an initial depth estimate the binoctree is adaptively subdivided throughout the optimization; previous methods use a fixed depth that leaves the scene undersampled. In comparison with three neural optimization methods and two non-neural methods ours shows decreased geometry error on average especially in a detailed scene while significantly reducing the required number of voxels to represent such details.

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Generating Content for HDR Deghosting from Frequency View

http://arxiv.org/abs/2404.00849

Tao Hu, Qingsen Yan, Yuankai Qi, Yanning Zhang

Recovering ghost-free High Dynamic Range (HDR) images from multiple Low Dynamic Range (LDR) images becomes challenging when the LDR images exhibit saturation and significant motion. Recent Diffusion Models (DMs) have been introduced in HDR imaging field demonstrating promising performance particularly in achieving visually perceptible results compared to previous DNN-based methods. However DMs require extensive iterations with large models to estimate entire images resulting in inefficiency that hinders their practical application. To address this challenge we propose the Low-Frequency aware Diffusion (LF-Diff) model for ghost-free HDR imaging. The key idea of LF-Diff is implementing the DMs in a highly compacted latent space and integrating it into a regression-based model to enhance the details of reconstructed images. Specifically as low-frequency information is closely related to human visual perception we propose to utilize DMs to create compact low-frequency priors for the reconstruction process. In addition to take full advantage of the above low-frequency priors the Dynamic HDR Reconstruction Network (DHRNet) is carried out in a regression-based manner to obtain final HDR images. Extensive experiments conducted on synthetic and real-world benchmark datasets demonstrate that our LF-Diff performs favorably against several state-of-the-art methods and is 10x faster than previous DM-based methods.

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Iterated Learning Improves Compositionality in Large Vision-Language Models

http://arxiv.org/abs/2404.02145

Chenhao Zheng, Jieyu Zhang, Aniruddha Kembhavi, Ranjay Krishna

A fundamental characteristic common to both human vision and natural language is their compositional nature. Yet despite the performance gains contributed by large vision and language pretraining recent investigations find that most--if not all--our state-of-the-art vision-language models struggle at compositionality. They are unable to distinguish between images of "a girl in white facing a man in black" and "a girl in black facing a man in white". Moreover prior work suggests that compositionality doesn't arise with scale: larger model sizes or training data don't help. This paper develops a new iterated training algorithm that incentivizes compositionality. We draw on decades of cognitive science research that identifies cultural transmission--the need to teach a new generation--as a necessary inductive prior that incentivizes humans to develop compositional languages. Specifically we reframe vision-language contrastive learning as the Lewis Signaling Game between a vision agent and a language agent and operationalize cultural transmission by iteratively resetting one of the agent's weights during training. After every iteration this training paradigm induces representations that become "easier to learn" a property of compositional languages: e.g. our model trained on CC3M and CC12M improves standard CLIP by 4.7% 4.0% respectfully in the SugarCrepe benchmark.

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Event Stream-based Visual Object Tracking: A High-Resolution Benchmark Dataset and A Novel Baseline

http://arxiv.org/abs/2309.14611

Xiao Wang, Shiao Wang, Chuanming Tang, Lin Zhu, Bo Jiang, Yonghong Tian, Jin Tang

Tracking with bio-inspired event cameras has garnered increasing interest in recent years. Existing works either utilize aligned RGB and event data for accurate tracking or directly learn an event-based tracker. The former incurs higher inference costs while the latter may be susceptible to the impact of noisy events or sparse spatial resolution. In this paper we propose a novel hierarchical knowledge distillation framework that can fully utilize multi-modal / multi-view information during training to facilitate knowledge transfer enabling us to achieve high-speed and low-latency visual tracking during testing by using only event signals. Specifically a teacher Transformer-based multi-modal tracking framework is first trained by feeding the RGB frame and event stream simultaneously. Then we design a new hierarchical knowledge distillation strategy which includes pairwise similarity feature representation and response maps-based knowledge distillation to guide the learning of the student Transformer network. In particular since existing event-based tracking datasets are all low-resolution (346 * 260) we propose the first large-scale high-resolution (1280 * 720) dataset named EventVOT. It contains 1141 videos and covers a wide range of categories such as pedestrians vehicles UAVs ping pong etc. Extensive experiments on both low-resolution (FE240hz VisEvent COESOT) and our newly proposed high-resolution EventVOT dataset fully validated the effectiveness of our proposed method. The dataset evaluation toolkit and source code will be released.

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LiDAR-Net: A Real-scanned 3D Point Cloud Dataset for Indoor Scenes

Yanwen Guo, Yuanqi Li, Dayong Ren, Xiaohong Zhang, Jiawei Li, Liang Pu, Changfeng Ma, Xiaoyu Zhan, Jie Guo, Mingqiang Wei, Yan Zhang, Piaopiao Yu, Shuangyu Yang, Donghao Ji, Huisheng Ye, Hao Sun, Yansong Liu, Yinuo Chen, Jiaqi Zhu, Hongyu Liu

In this paper we present LiDAR-Net a new real-scanned indoor point cloud dataset containing nearly 3.6 billion precisely point-level annotated points covering an expansive area of 30000m^2. It encompasses three prevalent daily environments including learning scenes working scenes and living scenes. LiDAR-Net is characterized by its non-uniform point distribution e.g. scanning holes and scanning lines. Additionally it meticulously records and annotates scanning anomalies including reflection noise and ghost. These anomalies stem from specular reflections on glass or metal as well as distortions due to moving persons. LiDAR-Net's realistic representation of non-uniform distribution and anomalies significantly enhances the training of deep learning models leading to improved generalization in practical applications. We thoroughly evaluate the performance of state-of-the-art algorithms on LiDAR-Net and provide a detailed analysis of the results. Crucially our research identifies several fundamental challenges in understanding indoor point clouds contributing essential insights to future explorations in this field. Our dataset can be found online: http://lidar-net.njumeta.com

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Dual DETRs for Multi-Label Temporal Action Detection

http://arxiv.org/abs/2404.00653

Yuhan Zhu, Guozhen Zhang, Jing Tan, Gangshan Wu, Limin Wang

Temporal Action Detection (TAD) aims to identify the action boundaries and the corresponding category within untrimmed videos. Inspired by the success of DETR in object detection several methods have adapted the query-based framework to the TAD task. However these approaches primarily followed DETR to predict actions at the instance level (i.e. identify each action by its center point) leading to sub-optimal boundary localization. To address this issue we propose a new Dual-level query-based TAD framework namely DualDETR to detect actions from both instance-level and boundary-level. Decoding at different levels requires semantics of different granularity therefore we introduce a two-branch decoding structure. This structure builds distinctive decoding processes for different levels facilitating explicit capture of temporal cues and semantics at each level. On top of the two-branch design we present a joint query initialization strategy to align queries from both levels. Specifically we leverage encoder proposals to match queries from each level in a one-to-one manner. Then the matched queries are initialized using position and content prior from the matched action proposal. The aligned dual-level queries can refine the matched proposal with complementary cues during subsequent decoding. We evaluate DualDETR on three challenging multi-label TAD benchmarks. The experimental results demonstrate the superior performance of DualDETR to the existing state-of-the-art methods achieving a substantial improvement under det-mAP and delivering impressive results under seg-mAP.

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Rich Human Feedback for Text-to-Image Generation

http://arxiv.org/abs/2312.10240

Youwei Liang, Junfeng He, Gang Li, Peizhao Li, Arseniy Klimovskiy, Nicholas Carolan, Jiao Sun, Jordi Pont-Tuset, Sarah Young, Feng Yang, Junjie Ke, Krishnamurthy Dj Dvijotham, Katherine M. Collins, Yiwen Luo, Yang Li, Kai J Kohlhoff, Deepak Ramachandran, Vidhya Navalpakkam

Recent Text-to-Image (T2I) generation models such as Stable Diffusion and Imagen have made significant progress in generating high-resolution images based on text descriptions. However many generated images still suffer from issues such as artifacts/implausibility misalignment with text descriptions and low aesthetic quality. Inspired by the success of Reinforcement Learning with Human Feedback (RLHF) for large language models prior works collected human-provided scores as feedback on generated images and trained a reward model to improve the T2I generation. In this paper we enrich the feedback signal by (i) marking image regions that are implausible or misaligned with the text and (ii) annotating which words in the text prompt are misrepresented or missing on the image. We collect such rich human feedback on 18K generated images (RichHF-18K) and train a multimodal transformer to predict the rich feedback automatically. We show that the predicted rich human feedback can be leveraged to improve image generation for example by selecting high-quality training data to finetune and improve the generative models or by creating masks with predicted heatmaps to inpaint the problematic regions. Notably the improvements generalize to models (Muse) beyond those used to generate the images on which human feedback data were collected (Stable Diffusion variants). The RichHF-18K data set will be released in our GitHub repository: https://github.com/google-research/google-research/tree/master/richhf_18k.

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360DVD: Controllable Panorama Video Generation with 360-Degree Video Diffusion Model

http://arxiv.org/abs/2401.06578

Qian Wang, Weiqi Li, Chong Mou, Xinhua Cheng, Jian Zhang

Panorama video recently attracts more interest in both study and application courtesy of its immersive experience. Due to the expensive cost of capturing 360-degree panoramic videos generating desirable panorama videos by prompts is urgently required. Lately the emerging text-to-video (T2V) diffusion methods demonstrate notable effectiveness in standard video generation. However due to the significant gap in content and motion patterns between panoramic and standard videos these methods encounter challenges in yielding satisfactory 360-degree panoramic videos. In this paper we propose a pipeline named 360-Degree Video Diffusion model (360DVD) for generating 360-degree panoramic videos based on the given prompts and motion conditions. Specifically we introduce a lightweight 360-Adapter accompanied by 360 Enhancement Techniques to transform pre-trained T2V models for panorama video generation. We further propose a new panorama dataset named WEB360 consisting of panoramic video-text pairs for training 360DVD addressing the absence of captioned panoramic video datasets. Extensive experiments demonstrate the superiority and effectiveness of 360DVD for panorama video generation.

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Map-Relative Pose Regression for Visual Re-Localization

http://arxiv.org/abs/2404.09884

Shuai Chen, Tommaso Cavallari, Victor Adrian Prisacariu, Eric Brachmann

Pose regression networks predict the camera pose of a query image relative to a known environment. Within this family of methods absolute pose regression (APR) has recently shown promising accuracy in the range of a few centimeters in position error. APR networks encode the scene geometry implicitly in their weights. To achieve high accuracy they require vast amounts of training data that realistically can only be created using novel view synthesis in a days-long process. This process has to be repeated for each new scene again and again. We present a new approach to pose regression map-relative pose regression (marepo) that satisfies the data hunger of the pose regression network in a scene-agnostic fashion. We condition the pose regressor on a scene-specific map representation such that its pose predictions are relative to the scene map. This allows us to train the pose regressor across hundreds of scenes to learn the generic relation between a scene-specific map representation and the camera pose. Our map-relative pose regressor can be applied to new map representations immediately or after mere minutes of fine-tuning for the highest accuracy. Our approach outperforms previous pose regression methods by far on two public datasets indoor and outdoor. Code is available: https://nianticlabs.github.io/marepo.

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Implicit Event-RGBD Neural SLAM

http://arxiv.org/abs/2311.11013

Delin Qu, Chi Yan, Dong Wang, Jie Yin, Qizhi Chen, Dan Xu, Yiting Zhang, Bin Zhao, Xuelong Li

Implicit neural SLAM has achieved remarkable progress recently. Nevertheless existing methods face significant challenges in non-ideal scenarios such as motion blur or lighting variation which often leads to issues like convergence failures localization drifts and distorted mapping. To address these challenges we propose EN-SLAM the first event-RGBD implicit neural SLAM framework which effectively leverages the high rate and high dynamic range advantages of event data for tracking and mapping. Specifically EN-SLAM proposes a differentiable CRF (Camera Response Function) rendering technique to generate distinct RGB and event camera data via a shared radiance field which is optimized by learning a unified implicit representation with the captured event and RGBD supervision. Moreover based on the temporal difference property of events we propose a temporal aggregating optimization strategy for the event joint tracking and global bundle adjustment capitalizing on the consecutive difference constraints of events significantly enhancing tracking accuracy and robustness. Finally we construct the simulated dataset DEV-Indoors and real captured dataset DEV-Reals containing 6 scenes 17 sequences with practical motion blur and lighting changes for evaluations. Experimental results show that our method outperforms the SOTA methods in both tracking ATE and mapping ACC with a real-time 17 FPS in various challenging environments. Project page: https://delinqu.github.io/EN-SLAM.

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Virtual Immunohistochemistry Staining for Histological Images Assisted by Weakly-supervised Learning

Jiahan Li, Jiuyang Dong, Shenjin Huang, Xi Li, Junjun Jiang, Xiaopeng Fan, Yongbing Zhang

Recently virtual staining technology has greatly promoted the advancement of histopathology. Despite the practical successes achieved the outstanding performance of most virtual staining methods relies on hard-to-obtain paired images in training. In this paper we propose a method for virtual immunohistochemistry (IHC) staining named confusion-GAN which does not require paired images and can achieve comparable performance to supervised algorithms. Specifically we propose a multi-branch discriminator which judges if the features of generated images can be embedded into the feature pool of target domain images to improve the visual quality of generated images. Meanwhile we also propose a novel patch-level pathology information extractor which is assisted by multiple instance learning to ensure pathological consistency during virtual staining. Extensive experiments were conducted on three types of IHC images including a high-resolution hepatocellular carcinoma immunohistochemical dataset proposed by us. The results demonstrated that our proposed confusion-GAN can generate highly realistic images that are capable of deceiving even experienced pathologists. Furthermore compared to using H&E images directly the downstream diagnosis achieved higher accuracy when using images generated by confusion-GAN. Our dataset and codes will be available at https://github.com/jiahanli2022/confusion-GAN.

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DeCoTR: Enhancing Depth Completion with 2D and 3D Attentions

http://arxiv.org/abs/2403.12202

Yunxiao Shi, Manish Kumar Singh, Hong Cai, Fatih Porikli

In this paper we introduce a novel approach that harnesses both 2D and 3D attentions to enable highly accurate depth completion without requiring iterative spatial propagations. Specifically we first enhance a baseline convolutional depth completion model by applying attention to 2D features in the bottleneck and skip connections. This effectively improves the performance of this simple network and sets it on par with the latest complex transformer-based models. Leveraging the initial depths and features from this network we uplift the 2D features to form a 3D point cloud and construct a 3D point transformer to process it allowing the model to explicitly learn and exploit 3D geometric features. In addition we propose normalization techniques to process the point cloud which improves learning and leads to better accuracy than directly using point transformers off the shelf. Furthermore we incorporate global attention on downsampled point cloud features which enables long-range context while still being computationally feasible. We evaluate our method DeCoTR on established depth completion benchmarks including NYU Depth V2 and KITTI showcasing that it sets new state-of-the-art performance. We further conduct zero-shot evaluations on ScanNet and DDAD benchmarks and demonstrate that DeCoTR has superior generalizability compared to existing approaches.

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Utility-Fairness Trade-Offs and How to Find Them

http://arxiv.org/abs/2404.09454

Sepehr Dehdashtian, Bashir Sadeghi, Vishnu Naresh Boddeti

When building classification systems with demographic fairness considerations there are two objectives to satisfy: 1) maximizing utility for the specific task and 2) ensuring fairness w.r.t. a known demographic attribute. These objectives often compete so optimizing both can lead to a trade-off between utility and fairness. While existing works acknowledge the trade-offs and study their limits two questions remain unanswered: 1) What are the optimal tradeoffs between utility and fairness? and 2) How can we numerically quantify these trade-offs from data for a desired prediction task and demographic attribute of interest? This paper addresses these questions. We introduce two utility-fairness trade-offs: the Data-Space and Label-Space Trade-off. The trade-offs reveal three regions within the utility-fairness plane delineating what is fully and partially possible and impossible. We propose U-FaTE a method to numerically quantify the trade-offs for a given prediction task and group fairness definition from data samples. Based on the trade-offs we introduce a new scheme for evaluating representations. An extensive evaluation of fair representation learning methods and representations from over 1000 pre-trained models revealed that most current approaches are far from the estimated and achievable fairness-utility trade-offs across multiple datasets and prediction tasks.

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Domain-Specific Block Selection and Paired-View Pseudo-Labeling for Online Test-Time Adaptation

http://arxiv.org/abs/2404.10966

Yeonguk Yu, Sungho Shin, Seunghyeok Back, Mihwan Ko, Sangjun Noh, Kyoobin Lee

Test-time adaptation (TTA) aims to adapt a pre-trained model to a new test domain without access to source data after deployment. Existing approaches typically rely on self-training with pseudo-labels since ground-truth cannot be obtained from test data. Although the quality of pseudo labels is important for stable and accurate long-term adaptation it has not been previously addressed. In this work we propose DPLOT a simple yet effective TTA framework that consists of two components: (1) domain-specific block selection and (2) pseudo-label generation using paired-view images. Specifically we select blocks that involve domain-specific feature extraction and train these blocks by entropy minimization. After blocks are adjusted for current test domain we generate pseudo-labels by averaging given test images and corresponding flipped counterparts. By simply using flip augmentation we prevent a decrease in the quality of the pseudo-labels which can be caused by the domain gap resulting from strong augmentation. Our experimental results demonstrate that DPLOT outperforms previous TTA methods in CIFAR10-C CIFAR100-C and ImageNet-C benchmarks reducing error by up to 5.4% 9.1% and 2.9% respectively. Also we provide an extensive analysis to demonstrate effectiveness of our framework. Code is available at https://github.com/gist-ailab/domain-specific-block-selection-and-paired-view-pseudo-labeling-for-online-TTA.

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Aerial Lifting: Neural Urban Semantic and Building Instance Lifting from Aerial Imagery

http://arxiv.org/abs/2403.11812

Yuqi Zhang, Guanying Chen, Jiaxing Chen, Shuguang Cui

We present a neural radiance field method for urban-scale semantic and building-level instance segmentation from aerial images by lifting noisy 2D labels to 3D. This is a challenging problem due to two primary reasons. Firstly objects in urban aerial images exhibit substantial variations in size including buildings cars and roads which pose a significant challenge for accurate 2D segmentation. Secondly the 2D labels generated by existing segmentation methods suffer from the multi-view inconsistency problem especially in the case of aerial images where each image captures only a small portion of the entire scene. To overcome these limitations we first introduce a scale-adaptive semantic label fusion strategy that enhances the segmentation of objects of varying sizes by combining labels predicted from different altitudes harnessing the novel-view synthesis capabilities of NeRF. We then introduce a novel cross-view instance label grouping strategy based on the 3D scene representation to mitigate the multi-view inconsistency problem in the 2D instance labels. Furthermore we exploit multi-view reconstructed depth priors to improve the geometric quality of the reconstructed radiance field resulting in enhanced segmentation results. Experiments on multiple real-world urban-scale datasets demonstrate that our approach outperforms existing methods highlighting its effectiveness. The source code is available at https://github.com/zyqz97/Aerial_lifting.

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SAOR: Single-View Articulated Object Reconstruction

http://arxiv.org/abs/2303.13514

Mehmet Aygun, Oisin Mac Aodha

We introduce SAOR a novel approach for estimating the 3D shape texture and viewpoint of an articulated object from a single image captured in the wild. Unlike prior approaches that rely on pre-defined category-specific 3D templates or tailored 3D skeletons SAOR learns to articulate shapes from single-view image collections with a skeleton-free part-based model without requiring any 3D object shape priors. To prevent ill-posed solutions we propose a cross-instance consistency loss that exploits disentangled object shape deformation and articulation. This is helped by a new silhouette-based sampling mechanism to enhance viewpoint diversity during training. Our method only requires estimated object silhouettes and relative depth maps from off-the-shelf pre-trained networks during training. At inference time given a single-view image it efficiently outputs an explicit mesh representation. We obtain improved qualitative and quantitative results on challenging quadruped animals compared to relevant existing work.

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A Theory of Joint Light and Heat Transport for Lambertian Scenes

Mani Ramanagopal, Sriram Narayanan, Aswin C. Sankaranarayanan, Srinivasa G. Narasimhan

We present a novel theory that establishes the relationship between light transport in visible and thermal infrared and heat transport in solids. We show that heat generated due to light absorption can be estimated by modeling heat transport using a thermal camera. For situations where heat conduction is negligible we analytically solve the heat transport equation to derive a simple expression relating the change in thermal image intensity to the absorbed light intensity and heat capacity of the material. Next we prove that intrinsic image decomposition for Lambertian scenes becomes a well-posed problem if one has access to the absorbed light. Our theory generalizes to arbitrary shapes and unstructured illumination. Our theory is based on applying energy conservation principle at each pixel independently. We validate our theory using real-world experiments on diffuse objects made of different materials that exhibit both direct and global components (inter-reflections) of light transport under unknown complex lighting.

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iKUN: Speak to Trackers without Retraining

http://arxiv.org/abs/2312.16245

Yunhao Du, Cheng Lei, Zhicheng Zhao, Fei Su

Referring multi-object tracking (RMOT) aims to track multiple objects based on input textual descriptions. Previous works realize it by simply integrating an extra textual module into the multi-object tracker. However they typically need to retrain the entire framework and have difficulties in optimization. In this work we propose an insertable Knowledge Unification Network termed iKUN to enable communication with off-the-shelf trackers in a plug-and-play manner. Concretely a knowledge unification module (KUM) is designed to adaptively extract visual features based on textual guidance. Meanwhile to improve the localization accuracy we present a neural version of Kalman filter (NKF) to dynamically adjust process noise and observation noise based on the current motion status. Moreover to address the problem of open-set long-tail distribution of textual descriptions a test-time similarity calibration method is proposed to refine the confidence score with pseudo frequency. Extensive experiments on Refer-KITTI dataset verify the effectiveness of our framework. Finally to speed up the development of RMOT we also contribute a more challenging dataset Refer-Dance by extending public DanceTrack dataset with motion and dressing descriptions. The codes and dataset are available at https://github.com/dyhBUPT/iKUN.

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RankMatch: Exploring the Better Consistency Regularization for Semi-supervised Semantic Segmentation

Huayu Mai, Rui Sun, Tianzhu Zhang, Feng Wu

The key lie in semi-supervised semantic segmentation is how to fully exploit substantial unlabeled data to improve the model's generalization performance by resorting to constructing effective supervision signals. Most methods tend to directly apply contrastive learning to seek additional supervision to complement independent regular pixel-wise consistency regularization. However these methods tend not to be preferred ascribed to their complicated designs heavy memory footprints and susceptibility to confirmation bias. In this paper we analyze the bottlenecks exist in contrastive learning-based methods and offer a fresh perspective on inter-pixel correlations to construct more safe and effective supervision signals which is in line with the nature of semantic segmentation. To this end we develop a coherent RankMatch network including the construction of representative agents to model inter-pixel correlation beyond regular individual pixel-wise consistency and further unlock the potential of agents by modeling inter-agent relationships in pursuit of rank-aware correlation consistency. Extensive experimental results on multiple benchmarks including mitochondria segmentation demonstrate that RankMatch performs favorably against state-of-the-art methods. Particularly in the low-data regimes RankMatch achieves significant improvements.

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Facial Identity Anonymization via Intrinsic and Extrinsic Attention Distraction

Zhenzhong Kuang, Xiaochen Yang, Yingjie Shen, Chao Hu, Jun Yu

The unprecedented capture and application of face images raise increasing concerns on anonymization to fight against privacy disclosure. Most existing methods may suffer from the problem of excessive change of the identity-independent information or insufficient identity protection. In this paper we present a new face anonymization approach by distracting the intrinsic and extrinsic identity attentions. On the one hand we anonymize the identity information in the feature space by distracting the intrinsic identity attention. On the other we anonymize the visual clues (i.e. appearance and geometry structure) by distracting the extrinsic identity attention. Our approach allows for flexible and intuitive manipulation of face appearance and geometry structure to produce diverse results and it can also be used to instruct users to perform personalized anonymization. We conduct extensive experiments on multiple datasets and demonstrate that our approach outperforms state-of-the-art methods.

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3D-SceneDreamer: Text-Driven 3D-Consistent Scene Generation

Songchun Zhang, Yibo Zhang, Quan Zheng, Rui Ma, Wei Hua, Hujun Bao, Weiwei Xu, Changqing Zou

Text-driven 3D scene generation techniques have made rapid progress in recent years. Their success is mainly attributed to using existing generative models to iteratively perform image warping and inpainting to generate 3D scenes. However these methods heavily rely on the outputs of existing models leading to error accumulation in geometry and appearance that prevent the models from being used in various scenarios (e.g. outdoor and unreal scenarios). To address this limitation we generatively refine the newly generated local views by querying and aggregating global 3D information and then progressively generate the 3D scene. Specifically we employ a tri-plane features-based NeRF as a unified representation of the 3D scene to constrain global 3D consistency and propose a generative refinement network to synthesize new contents with higher quality by exploiting the natural image prior from 2D diffusion model as well as the global 3D information of the current scene. Our extensive experiments demonstrate that in comparison to previous methods our approach supports wide variety of scene generation and arbitrary camera trajectories with improved visual quality and 3D consistency.

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VMINer: Versatile Multi-view Inverse Rendering with Near- and Far-field Light Sources

Fan Fei, Jiajun Tang, Ping Tan, Boxin Shi

This paper introduces a versatile multi-view inverse rendering framework with near- and far-field light sources. Tackling the fundamental challenge of inherent ambiguity in inverse rendering our framework adopts a lightweight yet inclusive lighting model for different near- and far-field lights thus is able to make use of input images under varied lighting conditions available during capture. It leverages observations under each lighting to disentangle the intrinsic geometry and material from the external lighting using both neural radiance field rendering and physically-based surface rendering on the 3D implicit fields. After training the reconstructed scene is extracted to a textured triangle mesh for seamless integration into industrial rendering software for various applications. Quantitatively and qualitatively tested on synthetic and real-world scenes our method shows superiority to state-of-the-art multi-view inverse rendering methods in both speed and quality.

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RoHM: Robust Human Motion Reconstruction via Diffusion

http://arxiv.org/abs/2401.08570

Siwei Zhang, Bharat Lal Bhatnagar, Yuanlu Xu, Alexander Winkler, Petr Kadlecek, Siyu Tang, Federica Bogo

We propose RoHM an approach for robust 3D human motion reconstruction from monocular RGB(-D) videos in the presence of noise and occlusions. Most previous approaches either train neural networks to directly regress motion in 3D or learn data-driven motion priors and combine them with optimization at test time. RoHM is a novel diffusion-based motion model that conditioned on noisy and occluded input data reconstructs complete plausible motions in consistent global coordinates. Given the complexity of the problem -- requiring one to address different tasks (denoising and infilling) in different solution spaces (local and global motion) -- we decompose it into two sub-tasks and learn two models one for global trajectory and one for local motion. To capture the correlations between the two we then introduce a novel conditioning module combining it with an iterative inference scheme. We apply RoHM to a variety of tasks -- from motion reconstruction and denoising to spatial and temporal infilling. Extensive experiments on three popular datasets show that our method outperforms state-of-the-art approaches qualitatively and quantitatively while being faster at test time. The code is available at https://sanweiliti.github.io/ROHM/ROHM.html.

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Do You Remember? Dense Video Captioning with Cross-Modal Memory Retrieval

http://arxiv.org/abs/2404.07610

Minkuk Kim, Hyeon Bae Kim, Jinyoung Moon, Jinwoo Choi, Seong Tae Kim

There has been significant attention to the research on dense video captioning which aims to automatically localize and caption all events within untrimmed video. Several studies introduce methods by designing dense video captioning as a multitasking problem of event localization and event captioning to consider inter-task relations. However addressing both tasks using only visual input is challenging due to the lack of semantic content. In this study we address this by proposing a novel framework inspired by the cognitive information processing of humans. Our model utilizes external memory to incorporate prior knowledge. The memory retrieval method is proposed with cross-modal video-to-text matching. To effectively incorporate retrieved text features the versatile encoder and the decoder with visual and textual cross-attention modules are designed. Comparative experiments have been conducted to show the effectiveness of the proposed method on ActivityNet Captions and YouCook2 datasets. Experimental results show promising performance of our model without extensive pretraining from a large video dataset. Our code is available at https://github.com/ailab-kyunghee/CM2_DVC.

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DuPL: Dual Student with Trustworthy Progressive Learning for Robust Weakly Supervised Semantic Segmentation

http://arxiv.org/abs/2403.11184

Yuanchen Wu, Xichen Ye, Kequan Yang, Jide Li, Xiaoqiang Li

Recently One-stage Weakly Supervised Semantic Segmentation (WSSS) with image-level labels has gained increasing interest due to simplification over its cumbersome multi-stage counterpart. Limited by the inherent ambiguity of Class Activation Map (CAM) we observe that one-stage pipelines often encounter confirmation bias caused by incorrect CAM pseudo-labels impairing their final segmentation performance. Although recent works discard many unreliable pseudo-labels to implicitly alleviate this issue they fail to exploit sufficient supervision for their models. To this end we propose a dual student framework with trustworthy progressive learning (DuPL). Specifically we propose a dual student network with a discrepancy loss to yield diverse CAMs for each sub-net. The two sub-nets generate supervision for each other mitigating the confirmation bias caused by learning their own incorrect pseudo-labels. In this process we progressively introduce more trustworthy pseudo-labels to be involved in the supervision through dynamic threshold adjustment with an adaptive noise filtering strategy. Moreover we believe that every pixel even discarded from supervision due to its unreliability is important for WSSS. Thus we develop consistency regularization on these discarded regions providing supervision of every pixel. Experiment results demonstrate the superiority of the proposed DuPL over the recent state-of-the-art alternatives on PASCAL VOC 2012 and MS COCO datasets. Code is available at https://github.com/Wu0409/DuPL.

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Learning with Structural Labels for Learning with Noisy Labels

Noo-ri Kim, Jin-Seop Lee, Jee-Hyong Lee

Deep Neural Networks (DNNs) have demonstrated remarkable performance across diverse domains and tasks with large-scale datasets. To reduce labeling costs for large-scale datasets semi-automated and crowdsourcing labeling methods are developed but their labels are inevitably noisy. Learning with Noisy Labels (LNL) approaches aim to train DNNs despite the presence of noisy labels. These approaches utilize the memorization effect to select correct labels and refine noisy ones which are then used for subsequent training. However these methods encounter a significant decrease in the model's generalization performance due to the inevitably existing noise labels. To overcome this limitation we propose a new approach to enhance learning with noisy labels by incorporating additional distribution information--structural labels. In order to leverage additional distribution information for generalization we employ a reverse k-NN which helps the model in achieving a better feature manifold and mitigating overfitting to noisy labels. The proposed method shows outperformed performance in multiple benchmark datasets with IDN and real-world noisy datasets.

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SurMo: Surface-based 4D Motion Modeling for Dynamic Human Rendering

http://arxiv.org/abs/2404.01225

Tao Hu, Fangzhou Hong, Ziwei Liu

Dynamic human rendering from video sequences has achieved remarkable progress by formulating the rendering as a mapping from static poses to human images. However existing methods focus on the human appearance reconstruction of every single frame while the temporal motion relations are not fully explored. In this paper we propose a new 4D motion modeling paradigm SurMo that jointly models the temporal dynamics and human appearances in a unified framework with three key designs: 1) Surface-based motion encoding that models 4D human motions with an efficient compact surface-based triplane. It encodes both spatial and temporal motion relations on the dense surface manifold of a statistical body template which inherits body topology priors for generalizable novel view synthesis with sparse training observations. 2) Physical motion decoding that is designed to encourage physical motion learning by decoding the motion triplane features at timestep t to predict both spatial derivatives and temporal derivatives at the next timestep t+1 in the training stage. 3) 4D appearance decoding that renders the motion triplanes into images by an efficient volumetric surface-conditioned renderer that focuses on the rendering of body surfaces with motion learning conditioning. Extensive experiments validate the state-of-the-art performance of our new paradigm and illustrate the expressiveness of surface-based motion triplanes for rendering high-fidelity view-consistent humans with fast motions and even motion-dependent shadows. Our project page is at: https://taohuumd.github.io/projects/SurMo.

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SPAD: Spatially Aware Multi-View Diffusers

Yash Kant, Aliaksandr Siarohin, Ziyi Wu, Michael Vasilkovsky, Guocheng Qian, Jian Ren, Riza Alp Guler, Bernard Ghanem, Sergey Tulyakov, Igor Gilitschenski

We present SPAD a novel approach for creating consistent multi-view images from text prompts or single images. To enable multi-view generation we repurpose a pretrained 2D diffusion model by extending its self-attention layers with cross-view interactions and fine-tune it on a high quality subset of Objaverse. We find that a naive extension of the self-attention proposed in prior work (e.g. MVDream) leads to content copying between views. Therefore we explicitly constrain the cross-view attention based on epipolar geometry. To further enhance 3D consistency we utilize Pl ?ucker coordinates derived from camera rays and inject them as positional encoding. This enables SPAD to reason over spatial proximity in 3D well. Compared to concurrent works that can only generate views at fixed azimuth and elevation (e.g. MVDream SyncDreamer) SPAD offers full camera control and achieves state-of-the-art results in novel view synthesis on unseen objects from the Objaverse and Google Scanned Objects datasets. Finally we demonstrate that text-to-3D generation using SPAD prevents the multi-face Janus issue.

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Gradient Reweighting: Towards Imbalanced Class-Incremental Learning

http://arxiv.org/abs/2402.18528

Jiangpeng He

Class-Incremental Learning (CIL) trains a model to continually recognize new classes from non-stationary data while retaining learned knowledge. A major challenge of CIL arises when applying to real-world data characterized by non-uniform distribution which introduces a dual imbalance problem involving (i) disparities between stored exemplars of old tasks and new class data (inter-phase imbalance) and (ii) severe class imbalances within each individual task (intra-phase imbalance). We show that this dual imbalance issue causes skewed gradient updates with biased weights in FC layers thus inducing over/under-fitting and catastrophic forgetting in CIL. Our method addresses it by reweighting the gradients towards balanced optimization and unbiased classifier learning. Additionally we observe imbalanced forgetting where paradoxically the instance-rich classes suffer higher performance degradation during CIL due to a larger amount of training data becoming unavailable in subsequent learning phases. To tackle this we further introduce a distribution-aware knowledge distillation loss to mitigate forgetting by aligning output logits proportionally with the distribution of lost training data. We validate our method on CIFAR-100 ImageNetSubset and Food101 across various evaluation protocols and demonstrate consistent improvements compared to existing works showing great potential to apply CIL in real-world scenarios with enhanced robustness and effectiveness.

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Hierarchical Spatio-temporal Decoupling for Text-to-Video Generation

http://arxiv.org/abs/2312.04483

Zhiwu Qing, Shiwei Zhang, Jiayu Wang, Xiang Wang, Yujie Wei, Yingya Zhang, Changxin Gao, Nong Sang

Despite diffusion models having shown powerful abilities to generate photorealistic images generating videos that are realistic and diverse still remains in its infancy. One of the key reasons is that current methods intertwine spatial content and temporal dynamics together leading to a notably increased complexity of text-to-video generation (T2V). In this work we propose HiGen a diffusion model-based method that improves performance by decoupling the spatial and temporal factors of videos from two perspectives i.e. structure level and content level. At the structure level we decompose the T2V task into two steps including spatial reasoning and temporal reasoning using a unified denoiser. Specifically we generate spatially coherent priors using text during spatial reasoning and then generate temporally coherent motions from these priors during temporal reasoning. At the content level we extract two subtle cues from the content of the input video that can express motion and appearance changes respectively. These two cues then guide the model's training for generating videos enabling flexible content variations and enhancing temporal stability. Through the decoupled paradigm HiGen can effectively reduce the complexity of this task and generate realistic videos with semantics accuracy and motion stability. Extensive experiments demonstrate the superior performance of HiGen over the state-of-the-art T2V methods. We have released our source code and models.

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PLACE: Adaptive Layout-Semantic Fusion for Semantic Image Synthesis

http://arxiv.org/abs/2403.01852

Zhengyao Lv, Yuxiang Wei, Wangmeng Zuo, Kwan-Yee K. Wong

Recent advancements in large-scale pre-trained text-to-image models have led to remarkable progress in semantic image synthesis. Nevertheless synthesizing high-quality images with consistent semantics and layout remains a challenge. In this paper we propose the adaPtive LAyout-semantiC fusion modulE (PLACE) that harnesses pre-trained models to alleviate the aforementioned issues. Specifically we first employ the layout control map to faithfully represent layouts in the feature space. Subsequently we combine the layout and semantic features in a timestep-adaptive manner to synthesize images with realistic details. During fine-tuning we propose the Semantic Alignment (SA) loss to further enhance layout alignment. Additionally we introduce the Layout-Free Prior Preservation (LFP) loss which leverages unlabeled data to maintain the priors of pre-trained models thereby improving the visual quality and semantic consistency of synthesized images. Extensive experiments demonstrate that our approach performs favorably in terms of visual quality semantic consistency and layout alignment. The source code and model are available at \href https://github.com/cszy98/PLACE/tree/main PLACE .

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Exploring Efficient Asymmetric Blind-Spots for Self-Supervised Denoising in Real-World Scenarios

http://arxiv.org/abs/2303.16783

Shiyan Chen, Jiyuan Zhang, Zhaofei Yu, Tiejun Huang

Self-supervised denoising has attracted widespread attention due to its ability to train without clean images. However noise in real-world scenarios is often spatially correlated which causes many self-supervised algorithms that assume pixel-wise independent noise to perform poorly. Recent works have attempted to break noise correlation with downsampling or neighborhood masking. However denoising on downsampled subgraphs can lead to aliasing effects and loss of details due to a lower sampling rate. Furthermore the neighborhood masking methods either come with high computational complexity or do not consider local spatial preservation during inference. Through the analysis of existing methods we point out that the key to obtaining high-quality and texture-rich results in real-world self-supervised denoising tasks is to train at the original input resolution structure and use asymmetric operations during training and inference. Based on this we propose Asymmetric Tunable Blind-Spot Network (AT-BSN) where the blind-spot size can be freely adjusted thus better balancing noise correlation suppression and image local spatial destruction during training and inference. In addition we regard the pre-trained AT-BSN as a meta-teacher network capable of generating various teacher networks by sampling different blind-spots. We propose a blind-spot based multi-teacher distillation strategy to distill a lightweight network significantly improving performance. Experimental results on multiple datasets prove that our method achieves state-of-the-art and is superior to other self-supervised algorithms in terms of computational overhead and visual effects.

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Gaussian Splatting SLAM

http://arxiv.org/abs/2312.06741

Hidenobu Matsuki, Riku Murai, Paul H.J. Kelly, Andrew J. Davison

We present the first application of 3D Gaussian Splatting in monocular SLAM the most fundamental but the hardest setup for Visual SLAM. Our method which runs live at 3fps utilises Gaussians as the only 3D representation unifying the required representation for accurate efficient tracking mapping and high-quality rendering. Designed for challenging monocular settings our approach is seamlessly extendable to RGB-D SLAM when an external depth sensor is available. Several innovations are required to continuously reconstruct 3D scenes with high fidelity from a live camera. First to move beyond the original 3DGS algorithm which requires accurate poses from an offline Structure from Motion (SfM) system we formulate camera tracking for 3DGS using direct optimisation against the 3D Gaussians and show that this enables fast and robust tracking with a wide basin of convergence. Second by utilising the explicit nature of the Gaussians we introduce geometric verification and regularisation to handle the ambiguities occurring in incremental 3D dense reconstruction. Finally we introduce a full SLAM system which not only achieves state-of-the-art results in novel view synthesis and trajectory estimation but also reconstruction of tiny and even transparent objects.

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Not All Classes Stand on Same Embeddings: Calibrating a Semantic Distance with Metric Tensor

Jae Hyeon Park, Gyoomin Lee, Seunggi Park, Sung In Cho

The consistency training (CT)-based semi-supervised learning (SSL) bites state-of-the-art performance on SSL-based image classification. However the existing CT-based SSL methods do not highlight the non-Euclidean characteristics and class-wise varieties of embedding spaces in an SSL model thus they cannot fully utilize the effectiveness of CT. Thus we propose a metric tensor-based consistency regularization exploiting the class-variant geometrical structure of embeddings on the high-dimensional feature space. The proposed method not only minimizes the prediction discrepancy between different views of a given image but also estimates the intrinsic geometric curvature of embedding spaces by employing the global and local metric tensors. The global metric tensor is used to globally estimate the class-invariant embeddings from the whole data distribution while the local metric tensor is exploited to estimate the class-variant embeddings of each cluster. The two metric tensors are optimized by the consistency regularization based on the weak and strong augmentation strategy. The proposed method provides the highest classification accuracy on average compared to the existing state-of-the-art SSL methods on conventional datasets.

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A Simple Recipe for Contrastively Pre-training Video-First Encoders Beyond 16 Frames

http://arxiv.org/abs/2312.07395

Pinelopi Papalampidi, Skanda Koppula, Shreya Pathak, Justin Chiu, Joe Heyward, Viorica Patraucean, Jiajun Shen, Antoine Miech, Andrew Zisserman, Aida Nematzdeh

Understanding long real-world videos requires modeling of long-range visual dependencies. To this end we explore video-first architectures building on the common paradigm of transferring large-scale image--text models to video via shallow temporal fusion. However we expose two limitations to the approach: (1) decreased spatial capabilities likely due to poor video--language alignment in standard video datasets and (2) higher memory consumption bottlenecking the number of frames that can be processed. To mitigate the memory bottleneck we systematically analyze the memory/accuracy trade-off of various efficient methods: factorized attention parameter-efficient image-to-video adaptation input masking and multi-resolution patchification. Surprisingly simply masking large portions of the video (up to 75%) during contrastive pre-training proves to be one of the most robust ways to scale encoders to videos up to 4.3 minutes at 1 FPS. Our simple approach for training long video-to-text models which scales to 1B parameters does not add new architectural complexity and is able to outperform the popular paradigm of using much larger LLMs as an information aggregator over segment-based information on benchmarks with long-range temporal dependencies (YouCook2 EgoSchema).

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DeMatch: Deep Decomposition of Motion Field for Two-View Correspondence Learning

Shihua Zhang, Zizhuo Li, Yuan Gao, Jiayi Ma

Two-view correspondence learning has recently focused on considering the coherence and smoothness of the motion field between an image pair. Dominant schemes include controlling the complexity of the field function with regularization or smoothing the field with local filters but the former suffers from heavy computational burden and the latter fails to accommodate discontinuities in the case of large scene disparities. In this paper inspired by Fourier expansion we propose a novel network called DeMatch which decomposes the motion field to retain its main "low-frequency" and smooth part. This achieves implicit regularization with lower computational cost and generates piecewise smoothness naturally. Specifically we first decompose the rough motion field that is contaminated by false matches into several different sub-fields which are highly smooth and contain the main energy of the original field. Then with these smooth sub-fields we recover a cleaner motion field from which correct motion vectors are subsequently derived. We also design a special masked decomposition strategy to further mitigate the negative influence of false matches. All the mentioned processes are finally implemented in a discrete and learnable manner avoiding the difficulty of calculating real dense fields. Extensive experiments reveal that DeMatch outperforms state-of-the-art methods in multiple tasks and shows promising low computational usage and piecewise smoothness property. The code and trained models are publicly available at https://github.com/SuhZhang/DeMatch.

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Hierarchical Diffusion Policy for Kinematics-Aware Multi-Task Robotic Manipulation

http://arxiv.org/abs/2403.03890

Xiao Ma, Sumit Patidar, Iain Haughton, Stephen James

This paper introduces Hierarchical Diffusion Policy (HDP) a hierarchical agent for multi-task robotic manipulation. HDP factorises a manipulation policy into a hierarchical structure: a high-level task-planning agent which predicts a distant next-best end-effector pose (NBP) and a low-level goal-conditioned diffusion policy which generates optimal motion trajectories. The factorised policy representation allows HDP to tackle both long-horizon task planning while generating fine-grained low-level actions. To generate context-aware motion trajectories while satisfying robot kinematics constraints we present a novel kinematics-aware goal-conditioned control agent Robot Kinematics Diffuser (RK-Diffuser). Specifically RK-Diffuser learns to generate both the end-effector pose and joint position trajectories and distill the accurate but kinematics-unaware end-effector pose diffuser to the kinematics-aware but less accurate joint position diffuser via differentiable kinematics. Empirically we show that HDP achieves a significantly higher success rate than the state-of-the-art methods in both simulation and real-world.

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Efficient Multi-scale Network with Learnable Discrete Wavelet Transform for Blind Motion Deblurring

http://arxiv.org/abs/2401.00027

Xin Gao, Tianheng Qiu, Xinyu Zhang, Hanlin Bai, Kang Liu, Xuan Huang, Hu Wei, Guoying Zhang, Huaping Liu

Coarse-to-fine schemes are widely used in traditional single-image motion deblur; however in the context of deep learning existing multi-scale algorithms not only require the use of complex modules for feature fusion of low-scale RGB images and deep semantics but also manually generate low-resolution pairs of images that do not have sufficient confidence. In this work we propose a multi-scale network based on single-input and multiple-outputs(SIMO) for motion deblurring. This simplifies the complexity of algorithms based on a coarse-to-fine scheme. To alleviate restoration defects impacting detail information brought about by using a multi-scale architecture we combine the characteristics of real-world blurring trajectories with a learnable wavelet transform module to focus on the directional continuity and frequency features of the step-by-step transitions between blurred images to sharp images. In conclusion we propose a multi-scale network with a learnable discrete wavelet transform (MLWNet) which exhibits state-of-the-art performance on multiple real-world deblurred datasets in terms of both subjective and objective quality as well as computational efficiency.

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MaskPLAN: Masked Generative Layout Planning from Partial Input

Hang Zhang, Anton Savov, Benjamin Dillenburger

Layout planning spanning from architecture to interior design is a slow iterative exploration of ill-defined problems adopting a "I'll know it when I see it" approach to potential solutions. Recent advances in generative models promise automating layout generation yet often overlook the crucial role of user-guided iteration cannot generate full solutions from incomplete design ideas and do not learn for the inter-dependency of layout attributes. To address these limitations we propose MaskPLAN a novel generative model based on Graph-structured Dynamic Masked Autoencoders (GDMAE) featuring five transformers generating a blend of graph-based and image-based layout attributes. MaskPLAN lets users generate and adjust layouts with partial attribute definitions create alternatives for preferences and practice new composition-driven or functionality-driven workflows. Through cross-attribute learning and the user input as a global conditional prior we ensure that design synthesis is calibrated at every intermediate stage maintaining its feasibility and practicality. Extensive evaluations show MaskPLAN's superior performance over existing methods across multiple metrics.

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Benchmarking the Robustness of Temporal Action Detection Models Against Temporal Corruptions

http://arxiv.org/abs/2403.20254

Runhao Zeng, Xiaoyong Chen, Jiaming Liang, Huisi Wu, Guangzhong Cao, Yong Guo

Temporal action detection (TAD) aims to locate action positions and recognize action categories in long-term untrimmed videos. Although many methods have achieved promising results their robustness has not been thoroughly studied. In practice we observe that temporal information in videos can be occasionally corrupted such as missing or blurred frames. Interestingly existing methods often incur a significant performance drop even if only one frame is affected. To formally evaluate the robustness we establish two temporal corruption robustness benchmarks namely THUMOS14-C and ActivityNet-v1.3-C. In this paper we extensively analyze the robustness of seven leading TAD methods and obtain some interesting findings: 1) Existing methods are particularly vulnerable to temporal corruptions and end-to-end methods are often more susceptible than those with a pre-trained feature extractor; 2) Vulnerability mainly comes from localization error rather than classification error; 3) When corruptions occur in the middle of an action instance TAD models tend to yield the largest performance drop. Besides building a benchmark we further develop a simple but effective robust training method to defend against temporal corruptions through the FrameDrop augmentation and Temporal-Robust Consistency loss. Remarkably our approach not only improves robustness but also yields promising improvements on clean data. We believe that this study will serve as a benchmark for future research in robust video analysis. Source code and models are available at https://github.com/Alvin-Zeng/temporal-robustness-benchmark.

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Open-World Human-Object Interaction Detection via Multi-modal Prompts

Jie Yang, Bingliang Li, Ailing Zeng, Lei Zhang, Ruimao Zhang

In this paper we develop MP-HOI a powerful Multi-modal Prompt-based HOI detector designed to leverage both textual descriptions for open-set generalization and visual exemplars for handling high ambiguity in descriptions realizing HOI detection in the open world. Specifically it integrates visual prompts into existing language-guided-only HOI detectors to handle situations where textual descriptions face difficulties in generalization and to address complex scenarios with high interaction ambiguity. To facilitate MP-HOI training we build a large-scale HOI dataset named Magic-HOI which gathers six existing datasets into a unified label space forming over 186K images with 2.4K objects 1.2K actions and 20K HOI interactions. Furthermore to tackle the long-tail issue within the Magic-HOI dataset we introduce an automated pipeline for generating realistically annotated HOI images and present SynHOI a high-quality synthetic HOI dataset containing 100K images. Leveraging these two datasets MP-HOI optimizes the HOI task as a similarity learning process between multi-modal prompts and objects/interactions via a unified contrastive loss to learn generalizable and transferable objects/interactions representations from large-scale data. MP-HOI could serve as a generalist HOI detector surpassing the HOI vocabulary of existing expert models by more than 30 times. Concurrently our results demonstrate that MP-HOI exhibits remarkable zero-shot capability in real-world scenarios and consistently achieves a new state-of-the-art performance across various benchmarks. Our project homepage is available at https://MP-HOI.github.io/.

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HMD-Poser: On-Device Real-time Human Motion Tracking from Scalable Sparse Observations

Peng Dai, Yang Zhang, Tao Liu, Zhen Fan, Tianyuan Du, Zhuo Su, Xiaozheng Zheng, Zeming Li

It is especially challenging to achieve real-time human motion tracking on a standalone VR Head-Mounted Display (HMD) such as Meta Quest and PICO. In this paper we propose HMD-Poser the first unified approach to recover full-body motions using scalable sparse observations from HMD and body-worn IMUs. In particular it can support a variety of input scenarios such as HMD HMD+2IMUs HMD+3IMUs etc. The scalability of inputs may accommodate users' choices for both high tracking accuracy and easy-to-wear. A lightweight temporal-spatial feature learning network is proposed in HMD-Poser to guarantee that the model runs in real-time on HMDs. Furthermore HMD-Poser presents online body shape estimation to improve the position accuracy of body joints. Extensive experimental results on the challenging AMASS dataset show that HMD-Poser achieves new state-of-the-art results in both accuracy and real-time performance. We also build a new free-dancing motion dataset to evaluate HMD-Poser's on-device performance and investigate the performance gap between synthetic data and real-captured sensor data. Finally we demonstrate our HMD-Poser with a real-time Avatar-driving application on a commercial HMD. Our code and free-dancing motion dataset are available \href https://pico-ai-team.github.io/hmd-poser here .

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UniMODE: Unified Monocular 3D Object Detection

http://arxiv.org/abs/2402.18573

Zhuoling Li, Xiaogang Xu, SerNam Lim, Hengshuang Zhao

Realizing unified monocular 3D object detection including both indoor and outdoor scenes holds great importance in applications like robot navigation. However involving various scenarios of data to train models poses challenges due to their significantly different characteristics e.g. diverse geometry properties and heterogeneous domain distributions. To address these challenges we build a detector based on the bird's-eye-view (BEV) detection paradigm where the explicit feature projection is beneficial to addressing the geometry learning ambiguity when employing multiple scenarios of data to train detectors. Then we split the classical BEV detection architecture into two stages and propose an uneven BEV grid design to handle the convergence instability caused by the aforementioned challenges. Moreover we develop a sparse BEV feature projection strategy to reduce computational cost and a unified domain alignment method to handle heterogeneous domains. Combining these techniques a unified detector UniMODE is derived which surpasses the previous state-of-the-art on the challenging Omni3D dataset (a large-scale dataset including both indoor and outdoor scenes) by 4.9% \rm AP_ 3D revealing the first successful generalization of a BEV detector to unified 3D object detection.

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Sherpa3D: Boosting High-Fidelity Text-to-3D Generation via Coarse 3D Prior

http://arxiv.org/abs/2312.06655

Fangfu Liu, Diankun Wu, Yi Wei, Yongming Rao, Yueqi Duan

Recently 3D content creation from text prompts has demonstrated remarkable progress by utilizing 2D and 3D diffusion models. While 3D diffusion models ensure great multi-view consistency their ability to generate high-quality and diverse 3D assets is hindered by the limited 3D data. In contrast 2D diffusion models find a distillation approach that achieves excellent generalization and rich details without any 3D data. However 2D lifting methods suffer from inherent view-agnostic ambiguity thereby leading to serious multi-face Janus issues where text prompts fail to provide sufficient guidance to learn coherent 3D results. Instead of retraining a costly viewpoint-aware model we study how to fully exploit easily accessible coarse 3D knowledge to enhance the prompts and guide 2D lifting optimization for refinement. In this paper we propose Sherpa3D a new text-to-3D framework that achieves high-fidelity generalizability and geometric consistency simultaneously. Specifically we design a pair of guiding strategies derived from the coarse 3D prior generated by the 3D diffusion model: a structural guidance for geometric fidelity and a semantic guidance for 3D coherence. Employing the two types of guidance the 2D diffusion model enriches the 3D content with diversified and high-quality results. Extensive experiments show the superiority of our Sherpa3D over the state-of-the-art text-to-3D methods in terms of quality and 3D consistency.

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Flexible Biometrics Recognition: Bridging the Multimodality Gap through Attention Alignment and Prompt Tuning

Leslie Ching Ow Tiong, Dick Sigmund, Chen-Hui Chan, Andrew Beng Jin Teoh

Periocular and face are complementary biometrics for identity management albeit with inherent limitations notably in scenarios involving occlusion due to sunglasses or masks. In response to these challenges we introduce Flexible Biometric Recognition (FBR) a novel framework designed to advance conventional face periocular and multimodal face-periocular biometrics across both intra- and cross-modality recognition tasks. FBR strategically utilizes the Multimodal Fusion Attention (MFA) and Multimodal Prompt Tuning (MPT) mechanisms within the Vision Transformer architecture. MFA facilitates the fusion of modalities ensuring cohesive alignment between facial and periocular embeddings while incorporating soft-biometrics to enhance the model's ability to discriminate between individuals. The fusion of three modalities is pivotal in exploring interrelationships between different modalities. Additionally MPT serves as a unifying bridge intertwining inputs and promoting cross-modality interactions while preserving their distinctive characteristics. The collaborative synergy of MFA and MPT enhances the shared features of the face and periocular with a specific emphasis on the ocular region yielding exceptional performance in both intra- and cross-modality recognition tasks. Rigorous experimentation across four benchmark datasets validates the noteworthy performance of the FBR model. The source code is available at https://github.com/MIS-DevWorks/FBR.

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Multi-agent Collaborative Perception via Motion-aware Robust Communication Network

Shixin Hong, Yu Liu, Zhi Li, Shaohui Li, You He

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.

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The Manga Whisperer: Automatically Generating Transcriptions for Comics

http://arxiv.org/abs/2401.10224

Ragav Sachdeva, Andrew Zisserman

In the past few decades Japanese comics commonly referred to as Manga have transcended both cultural and linguistic boundaries to become a true worldwide sensation. Yet the inherent reliance on visual cues and illustration within manga renders it largely inaccessible to individuals with visual impairments. In this work we seek to address this substantial barrier with the aim of ensuring that manga can be appreciated and actively engaged by everyone. Specifically we tackle the problem of diarisation i.e. generating a transcription of who said what and when in a fully automatic way. To this end we make the following contributions: (1) we present a unified model Magi that is able to (a) detect panels text boxes and character boxes (b) cluster characters by identity (without knowing the number of clusters apriori) and (c) associate dialogues to their speakers; (2) we propose a novel approach that is able to sort the detected text boxes in their reading order and generate a dialogue transcript; (3) we annotate an evaluation benchmark for this task using publicly available [English] manga pages.

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Exploring Region-Word Alignment in Built-in Detector for Open-Vocabulary Object Detection

Heng Zhang, Qiuyu Zhao, Linyu Zheng, Hao Zeng, Zhiwei Ge, Tianhao Li, Sulong Xu

Open-vocabulary object detection aims to detect novel categories that are independent from the base categories used during training. Most modern methods adhere to the paradigm of learning vision-language space from a large-scale multi-modal corpus and subsequently transferring the acquired knowledge to off-the-shelf detectors like Faster-RCNN. However information attenuation or destruction may occur during the process of knowledge transfer due to the domain gap hampering the generalization ability on novel categories. To mitigate this predicament in this paper we present a novel framework named BIND standing for Bulit-IN Detector to eliminate the need for module replacement or knowledge transfer to off-the-shelf detectors. Specifically we design a two-stage training framework with an Encoder-Decoder structure. In the first stage an image-text dual encoder is trained to learn region-word alignment from a corpus of image-text pairs. In the second stage a DETR-style decoder is trained to perform detection on annotated object detection datasets. In contrast to conventional manually designed non-adaptive anchors which generate numerous redundant proposals we develop an anchor proposal network that generates anchor proposals with high likelihood based on candidates adaptively thereby substantially improving detection efficiency. Experimental results on two public benchmarks COCO and LVIS demonstrate that our method stands as a state-of-the-art approach for open-vocabulary object detection.

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MovieChat: From Dense Token to Sparse Memory for Long Video Understanding

http://arxiv.org/abs/2307.16449

Enxin Song, Wenhao Chai, Guanhong Wang, Yucheng Zhang, Haoyang Zhou, Feiyang Wu, Haozhe Chi, Xun Guo, Tian Ye, Yanting Zhang, Yan Lu, Jenq-Neng Hwang, Gaoang Wang

Recently integrating video foundation models and large language models to build a video understanding system can overcome the limitations of specific pre-defined vision tasks. Yet existing systems can only handle videos with very few frames. For long videos the computation complexity memory cost and long-term temporal connection impose additional challenges. Taking advantage of the Atkinson-Shiffrin memory model with tokens in Transformers being employed as the carriers of memory in combination with our specially designed memory mechanism we propose the MovieChat to overcome these challenges. MovieChat achieves state-of-the-art performance in long video understanding along with the released MovieChat-1K benchmark with 1K long video and 14K manual annotations for validation of the effectiveness of our method. The code models and data can be found in https://rese1f.github.io/MovieChat.

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Comparing the Decision-Making Mechanisms by Transformers and CNNs via Explanation Methods

http://arxiv.org/abs/2212.06872

Mingqi Jiang, Saeed Khorram, Li Fuxin

In order to gain insights about the decision-making of different visual recognition backbones we propose two methodologies sub-explanation counting and cross-testing that systematically applies deep explanation algorithms on a dataset-wide basis and compares the statistics generated from the amount and nature of the explanations. These methodologies reveal the difference among networks in terms of two properties called compositionality and disjunctivism. Transformers and ConvNeXt are found to be more compositional in the sense that they jointly consider multiple parts of the image in building their decisions whereas traditional CNNs and distilled transformers are less compositional and more disjunctive which means that they use multiple diverse but smaller set of parts to achieve a confident prediction. Through further experiments we pinpointed the choice of normalization to be especially important in the compositionality of a model in that batch normalization leads to less compositionality while group and layer normalization lead to more. Finally we also analyze the features shared by different backbones and plot a landscape of different models based on their feature-use similarity.

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A Unified Diffusion Framework for Scene-aware Human Motion Estimation from Sparse Signals

http://arxiv.org/abs/2404.04890

Jiangnan Tang, Jingya Wang, Kaiyang Ji, Lan Xu, Jingyi Yu, Ye Shi

Estimating full-body human motion via sparse tracking signals from head-mounted displays and hand controllers in 3D scenes is crucial to applications in AR/VR. One of the biggest challenges to this task is the one-to-many mapping from sparse observations to dense full-body motions which endowed inherent ambiguities. To help resolve this ambiguous problem we introduce a new framework to combine rich contextual information provided by scenes to benefit full-body motion tracking from sparse observations. To estimate plausible human motions given sparse tracking signals and 3D scenes we develop \text S ^2Fusion a unified framework fusing \underline S cene and sparse \underline S ignals with a conditional dif\underline Fusion model. \text S ^2Fusion first extracts the spatial-temporal relations residing in the sparse signals via a periodic autoencoder and then produces time-alignment feature embedding as additional inputs. Subsequently by drawing initial noisy motion from a pre-trained prior \text S ^2Fusion utilizes conditional diffusion to fuse scene geometry and sparse tracking signals to generate full-body scene-aware motions. The sampling procedure of \text S ^2Fusion is further guided by a specially designed scene-penetration loss and phase-matching loss which effectively regularizes the motion of the lower body even in the absence of any tracking signals making the generated motion much more plausible and coherent. Extensive experimental results have demonstrated that our \text S ^2Fusion outperforms the state-of-the-art in terms of estimation quality and smoothness.

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Single Domain Generalization for Crowd Counting

http://arxiv.org/abs/2403.09124

Zhuoxuan Peng, S.-H. Gary Chan

Due to its promising results density map regression has been widely employed for image-based crowd counting. The approach however often suffers from severe performance degradation when tested on data from unseen scenarios the so-called "domain shift" problem. To address the problem we investigate in this work single domain generalization (SDG) for crowd counting. The existing SDG approaches are mainly for image classification and segmentation and can hardly be extended to our case due to its regression nature and label ambiguity (i.e. ambiguous pixel-level ground truths). We propose MPCount a novel effective SDG approach even for narrow source distribution. MPCount stores diverse density values for density map regression and reconstructs domain-invariant features by means of only one memory bank a content error mask and attention consistency loss. By partitioning the image into grids it employs patch-wise classification as an auxiliary task to mitigate label ambiguity. Through extensive experiments on different datasets MPCount is shown to significantly improve counting accuracy compared to the state of the art under diverse scenarios unobserved in the training data characterized by narrow source distribution. Code is available at https://github.com/Shimmer93/MPCount.

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Atlantis: Enabling Underwater Depth Estimation with Stable Diffusion

http://arxiv.org/abs/2312.12471

Fan Zhang, Shaodi You, Yu Li, Ying Fu

Monocular depth estimation has experienced significant progress on terrestrial images in recent years thanks to deep learning advancements. But it remains inadequate for underwater scenes primarily due to data scarcity. Given the inherent challenges of light attenuation and backscatter in water acquiring clear underwater images or precise depth is notably difficult and costly. To mitigate this issue learning-based approaches often rely on synthetic data or turn to self- or unsupervised manners. Nonetheless their performance is often hindered by domain gap and looser constraints. In this paper we propose a novel pipeline for generating photorealistic underwater images using accurate terrestrial depth. This approach facilitates the supervised training of models for underwater depth estimation effectively reducing the performance disparity between terrestrial and underwater environments. Contrary to previous synthetic datasets that merely apply style transfer to terrestrial images without scene content change our approach uniquely creates vivid non-existent underwater scenes by leveraging terrestrial depth data through the innovative Stable Diffusion model. Specifically we introduce a specialized Depth2Underwater ControlNet trained on prepared \ Underwater Depth Text\ data triplets for this generation task. Our newly developed dataset Atlantis enables terrestrial depth estimation models to achieve considerable improvements on unseen underwater scenes surpassing their terrestrial pretrained counterparts both quantitatively and qualitatively. Moreover we further show its practical utility by applying the improved depth in underwater image enhancement and its smaller domain gap from the LLVM perspective. Code and dataset are publicly available at https://github.com/zkawfanx/Atlantis.

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Matching Anything by Segmenting Anything

Siyuan Li, Lei Ke, Martin Danelljan, Luigi Piccinelli, Mattia Segu, Luc Van Gool, Fisher Yu

The robust association of the same objects across video frames in complex scenes is crucial for many applications especially object tracking. Current methods predominantly rely on labeled domain-specific video datasets which limits cross-domain generalization of learned similarity embeddings. We propose MASA a novel method for robust instance association learning capable of matching any objects within videos across diverse domains without tracking labels. Leveraging the rich object segmentation from the Segment Anything Model (SAM) MASA learns instance-level correspondence through exhausive data transformations. We treat the SAM outputs as dense object region proposals and learn to match those regions from a vast image collection. We further design a universal MASA adapter which can work in tandem with foundational segmentation or detection models and enable them to track any detected objects. Those combinations present strong zero-shot tracking ability in complex domains. Extensive tests on multiple challenging MOT and MOTS benchmarks indicate that the proposed method using only unlabelled static images achieves even better performance than state-of-the-art methods trained with fully annotated in-domain video sequences in zero-shot association. Our code is available at https://github.com/siyuanliii/masa.

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Task-Aware Encoder Control for Deep Video Compression

http://arxiv.org/abs/2404.04848

Xingtong Ge, Jixiang Luo, Xinjie Zhang, Tongda Xu, Guo Lu, Dailan He, Jing Geng, Yan Wang, Jun Zhang, Hongwei Qin

Prior research on deep video compression (DVC) for machine tasks typically necessitates training a unique codec for each specific task mandating a dedicated decoder per task. In contrast traditional video codecs employ a flexible encoder controller enabling the adaptation of a single codec to different tasks through mechanisms like mode prediction. Drawing inspiration from this we introduce an innovative encoder controller for deep video compression for machines. This controller features a mode prediction and a Group of Pictures (GoP) selection module. Our approach centralizes control at the encoding stage allowing for adaptable encoder adjustments across different tasks such as detection and tracking while maintaining compatibility with a standard pre-trained DVC decoder. Empirical evidence demonstrates that our method is applicable across multiple tasks with various existing pre-trained DVCs. Moreover extensive experiments demonstrate that our method outperforms previous DVC by about 25% bitrate for different tasks with only one pre-trained decoder.

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Multi-scale Dynamic and Hierarchical Relationship Modeling for Facial Action Units Recognition

http://arxiv.org/abs/2404.06443

Zihan Wang, Siyang Song, Cheng Luo, Songhe Deng, Weicheng Xie, Linlin Shen

Human facial action units (AUs) are mutually related in a hierarchical manner as not only they are associated with each other in both spatial and temporal domains but also AUs located in the same/close facial regions show stronger relationships than those of different facial regions. While none of existing approach thoroughly model such hierarchical inter-dependencies among AUs this paper proposes to comprehensively model multi-scale AU-related dynamic and hierarchical spatio-temporal relationship among AUs for their occurrences recognition. Specifically we first propose a novel multi-scale temporal differencing network with an adaptive weighting block to explicitly capture facial dynamics across frames at different spatial scales which specifically considers the heterogeneity of range and magnitude in different AUs' activation. Then a two-stage strategy is introduced to hierarchically model the relationship among AUs based on their spatial distribution (i.e. local and cross-region AU relationship modelling). Experimental results achieved on BP4D and DISFA show that our approach is the new state-of-the-art in the field of AU occurrence recognition. Our code is publicly available at https://github.com/CVI-SZU/MDHR.

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Decoupled Pseudo-labeling for Semi-Supervised Monocular 3D Object Detection

http://arxiv.org/abs/2403.17387

Jiacheng Zhang, Jiaming Li, Xiangru Lin, Wei Zhang, Xiao Tan, Junyu Han, Errui Ding, Jingdong Wang, Guanbin Li

We delve into pseudo-labeling for semi-supervised monocular 3D object detection (SSM3OD) and discover two primary issues: a misalignment between the prediction quality of 3D and 2D attributes and the tendency of depth supervision derived from pseudo-labels to be noisy leading to significant optimization conflicts with other reliable forms of supervision. To tackle these issues we introduce a novel decoupled pseudo-labeling (DPL) approach for SSM3OD. Our approach features a Decoupled Pseudo-label Generation (DPG) module designed to efficiently generate pseudo-labels by separately processing 2D and 3D attributes. This module incorporates a unique homography-based method for identifying dependable pseudo-labels in Bird's Eye View (BEV) space specifically for 3D attributes. Additionally we present a Depth Gradient Projection (DGP) module to mitigate optimization conflicts caused by noisy depth supervision of pseudo-labels effectively decoupling the depth gradient and removing conflicting gradients. This dual decoupling strategy--at both the pseudo-label generation and gradient levels--significantly improves the utilization of pseudo-labels in SSM3OD. Our comprehensive experiments on the KITTI benchmark demonstrate the superiority of our method over existing approaches.

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Temporally Consistent Unbalanced Optimal Transport for Unsupervised Action Segmentation

http://arxiv.org/abs/2404.01518

Ming Xu, Stephen Gould

We propose a novel approach to the action segmentation task for long untrimmed videos based on solving an optimal transport problem. By encoding a temporal consistency prior into a Gromov-Wasserstein problem we are able to decode a temporally consistent segmentation from a noisy affinity/matching cost matrix between video frames and action classes. Unlike previous approaches our method does not require knowing the action order for a video to attain temporal consistency. Furthermore our resulting (fused) Gromov-Wasserstein problem can be efficiently solved on GPUs using a few iterations of projected mirror descent. We demonstrate the effectiveness of our method in an unsupervised learning setting where our method is used to generate pseudo-labels for self-training. We evaluate our segmentation approach and unsupervised learning pipeline on the Breakfast 50-Salads YouTube Instructions and Desktop Assembly datasets yielding state-of-the-art results for the unsupervised video action segmentation task.

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Learning Transferable Negative Prompts for Out-of-Distribution Detection

http://arxiv.org/abs/2404.03248

Tianqi Li, Guansong Pang, Xiao Bai, Wenjun Miao, Jin Zheng

Existing prompt learning methods have shown certain capabilities in Out-of-Distribution (OOD) detection but the lack of OOD images in the target dataset in their training can lead to mismatches between OOD images and In-Distribution (ID) categories resulting in a high false positive rate. To address this issue we introduce a novel OOD detection method named 'NegPrompt' to learn a set of negative prompts each representing a negative connotation of a given class label for delineating the boundaries between ID and OOD images. It learns such negative prompts with ID data only without any reliance on external outlier data. Further current methods assume the availability of samples of all ID classes rendering them ineffective in open-vocabulary learning scenarios where the inference stage can contain novel ID classes not present during training. In contrast our learned negative prompts are transferable to novel class labels. Experiments on various ImageNet benchmarks show that NegPrompt surpasses state-of-the-art prompt-learning-based OOD detection methods and maintains a consistent lead in hard OOD detection in closed- and open-vocabulary classification scenarios. Code is available at https://github.com/mala-lab/negprompt.

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Long-Tail Class Incremental Learning via Independent Sub-prototype Construction

Xi Wang, Xu Yang, Jie Yin, Kun Wei, Cheng Deng

Long-tail class incremental learning (LT-CIL) is designed to perpetually acquire novel knowledge from an imbalanced and perpetually evolving data stream while ensuring the retention of previously acquired knowledge. The existing method only re-balances data distribution and ignores exploring the potential relationship between different samples causing non-robust representations and even severe forgetting in classes with few samples. In this paper we constructed two parallel spaces simultaneously: 1) Sub-prototype space and 2) Reminiscence space to learn robust representations while alleviating forgetfulness. Concretely we advance the concept of the sub-prototype space which amalgamates insights from diverse classes. This integration facilitates the mutual complementarity of varied knowledge thereby augmenting the attainment of more robust representations. Furthermore we introduce the reminiscence space which encapsulates each class distribution aiming to constraint model optimization and mitigate the phenomenon of forgetting. The tandem utilization of the two parallel spaces effectively alleviates the adverse consequences associated with imbalanced data distribution preventing forgetting without needing replay examples. Extensive experiments demonstrate that our method achieves state-of-the-art performance on various benchmarks.

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Learning with Unreliability: Fast Few-shot Voxel Radiance Fields with Relative Geometric Consistency

http://arxiv.org/abs/2403.17638

Yingjie Xu, Bangzhen Liu, Hao Tang, Bailin Deng, Shengfeng He

We propose a voxel-based optimization framework ReVoRF for few-shot radiance fields that strategically addresses the unreliability in pseudo novel view synthesis. Our method pivots on the insight that relative depth relationships within neighboring regions are more reliable than the absolute color values in disoccluded areas. Consequently we devise a bilateral geometric consistency loss that carefully navigates the trade-off between color fidelity and geometric accuracy in the context of depth consistency for uncertain regions. Moreover we present a reliability-guided learning strategy to discern and utilize the variable quality across synthesized views complemented by a reliability-aware voxel smoothing algorithm that smoothens the transition between reliable and unreliable data patches. Our approach allows for a more nuanced use of all available data promoting enhanced learning from regions previously considered unsuitable for high-quality reconstruction. Extensive experiments across diverse datasets reveal that our approach attains significant gains in efficiency and accuracy delivering rendering speeds of 3 FPS 7 mins to train a 360deg scene and a 5% improvement in PSNR over existing few-shot methods. Code is available at https://github.com/HKCLynn/ReVoRF

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Towards Understanding and Improving Adversarial Robustness of Vision Transformers

Samyak Jain, Tanima Dutta

Recent literature has demonstrated that vision transformers (VITs) exhibit superior performance compared to convolutional neural networks (CNNs). The majority of recent research on adversarial robustness however has predominantly focused on CNNs. In this work we bridge this gap by analyzing the effectiveness of existing attacks on VITs. We demonstrate that due to the softmax computations in every attention block in VITs they are inherently vulnerable to floating point underflow errors. This can lead to a gradient masking effect resulting in suboptimal attack strength of well-known attacks like PGD Carlini and Wagner (CW) GAMA and Patch attacks. Motivated by this we propose Adaptive Attention Scaling (AAS) attack that can automatically find the optimal scaling factors of pre-softmax outputs using gradient-based optimization. We show that the proposed simple strategy can be incorporated with any existing adversarial attacks as well as adversarial training methods and achieved improved performance. On VIT-B16 we demonstrate an improved attack strength of upto 2.2% on CIFAR10 and upto 2.9% on CIFAR100 by incorporating the proposed AAS attack with state-of-the-art single attack methods like GAMA attack. Further we utilise the proposed AAS attack for every few epochs in existing adversarial training methods which is termed as Adaptive Attention Scaling Adversarial Training (AAS-AT). On incorporating AAS-AT with existing methods we outperform them on VITs over 1.3-3.5% on CIFAR10. We observe improved performance on ImageNet-100 as well.

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EventEgo3D: 3D Human Motion Capture from Egocentric Event Streams

http://arxiv.org/abs/2404.08640

Christen Millerdurai, Hiroyasu Akada, Jian Wang, Diogo Luvizon, Christian Theobalt, Vladislav Golyanik

Monocular egocentric 3D human motion capture is a challenging and actively researched problem. Existing methods use synchronously operating visual sensors (e.g. RGB cameras) and often fail under low lighting and fast motions which can be restricting in many applications involving head-mounted devices. In response to the existing limitations this paper 1) introduces a new problem i.e. 3D human motion capture from an egocentric monocular event camera with a fisheye lens and 2) proposes the first approach to it called EventEgo3D (EE3D). Event streams have high temporal resolution and provide reliable cues for 3D human motion capture under high-speed human motions and rapidly changing illumination. The proposed EE3D framework is specifically tailored for learning with event streams in the LNES representation enabling high 3D reconstruction accuracy. We also design a prototype of a mobile head-mounted device with an event camera and record a real dataset with event observations and the ground-truth 3D human poses (in addition to the synthetic dataset). Our EE3D demonstrates robustness and superior 3D accuracy compared to existing solutions across various challenging experiments while supporting real-time 3D pose update rates of 140Hz.

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Holistic Features are almost Sufficient for Text-to-Video Retrieval

Kaibin Tian, Ruixiang Zhao, Zijie Xin, Bangxiang Lan, Xirong Li

For text-to-video retrieval (T2VR) which aims to retrieve unlabeled videos by ad-hoc textual queries CLIP-based methods currently lead the way. Compared to CLIP4Clip which is efficient and compact state-of-the-art models tend to compute video-text similarity through fine-grained cross-modal feature interaction and matching putting their scalability for large-scale T2VR applications into doubt. We propose TeachCLIP enabling a CLIP4Clip based student network to learn from more advanced yet computationally intensive models. In order to create a learning channel to convey fine-grained cross-modal knowledge from a heavy model to the student we add to CLIP4Clip a simple Attentional frame-Feature Aggregation (AFA) block which by design adds no extra storage / computation overhead at the retrieval stage. Frame-text relevance scores calculated by the teacher network are used as soft labels to supervise the attentive weights produced by AFA. Extensive experiments on multiple public datasets justify the viability of the proposed method. TeachCLIP has the same efficiency and compactness as CLIP4Clip yet has near-SOTA effectiveness.

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A Call to Reflect on Evaluation Practices for Age Estimation: Comparative Analysis of the State-of-the-Art and a Unified Benchmark

Jakub Paplhám, Vojt?ch Franc

Comparing different age estimation methods poses a challenge due to the unreliability of published results stemming from inconsistencies in the benchmarking process. Previous studies have reported continuous performance improvements over the past decade using specialized methods; however our findings challenge these claims. This paper identifies two trivial yet persistent issues with the currently used evaluation protocol and describes how to resolve them. We offer an extensive comparative analysis for state-of-the-art facial age estimation methods. Surprisingly we find that the performance differences between the methods are negligible compared to the effect of other factors such as facial alignment facial coverage image resolution model architecture or the amount of data used for pretraining. We use the gained insights to propose using FaRL as the backbone model and demonstrate its effectiveness on all public datasets. We make the source code and exact data splits public on GitHub and in the supplementary material.

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CosalPure: Learning Concept from Group Images for Robust Co-Saliency Detection

http://arxiv.org/abs/2403.18554

Jiayi Zhu, Qing Guo, Felix Juefei-Xu, Yihao Huang, Yang Liu, Geguang Pu

Co-salient object detection (CoSOD) aims to identify the common and salient (usually in the foreground) regions across a given group of images. Although achieving significant progress state-of-the-art CoSODs could be easily affected by some adversarial perturbations leading to substantial accuracy reduction. The adversarial perturbations can mislead CoSODs but do not change the high-level semantic information (e.g. concept) of the co-salient objects. In this paper we propose a novel robustness enhancement framework by first learning the concept of the co-salient objects based on the input group images and then leveraging this concept to purify adversarial perturbations which are subsequently fed to CoSODs for robustness enhancement. Specifically we propose CosalPure containing two modules i.e. group-image concept learning and concept-guided diffusion purification. For the first module we adopt a pre-trained text-to-image diffusion model to learn the concept of co-salient objects within group images where the learned concept is robust to adversarial examples. For the second module we map the adversarial image to the latent space and then perform diffusion generation by embedding the learned concept into the noise prediction function as an extra condition. Our method can effectively alleviate the influence of the SOTA adversarial attack containing different adversarial patterns including exposure and noise. The extensive results demonstrate that our method could enhance the robustness of CoSODs significantly.

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Uncertainty-aware Action Decoupling Transformer for Action Anticipation

Hongji Guo, Nakul Agarwal, Shao-Yuan Lo, Kwonjoon Lee, Qiang Ji

Human action anticipation aims at predicting what people will do in the future based on past observations. In this paper we introduce Uncertainty-aware Action Decoupling Transformer (UADT) for action anticipation. Unlike existing methods that directly predict action in a verb-noun pair format we decouple the action anticipation task into verb and noun anticipations separately. The objective is to make the two decoupled tasks assist each other and eventually improve the action anticipation task. Specifically we propose a two-stream Transformer-based architecture which is composed of a verb-to-noun model and a noun-to-verb model. The verb-to-noun model leverages the verb information to improve the noun prediction and the other way around. We extend the model in a probabilistic manner and quantify the predictive uncertainty of each decoupled task to select features. In this way the noun prediction leverages the most informative and redundancy-free verb features and verb prediction works similarly. Finally the two streams are combined dynamically based on their uncertainties to make the joint action anticipation. We demonstrate the efficacy of our method by achieving state-of-the-art performance on action anticipation benchmarks including EPIC-KITCHENS EGTEA Gaze+ and 50-Salads.

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MRFP: Learning Generalizable Semantic Segmentation from Sim-2-Real with Multi-Resolution Feature Perturbation

Sumanth Udupa, Prajwal Gurunath, Aniruddh Sikdar, Suresh Sundaram

Deep neural networks have shown exemplary performance on semantic scene understanding tasks on source domains but due to the absence of style diversity during training enhancing performance on unseen target domains using only single source domain data remains a challenging task. Generation of simulated data is a feasible alternative to retrieving large style-diverse real-world datasets as it is a cumbersome and budget-intensive process. However the large domain-specific inconsistencies between simulated and real-world data pose a significant generalization challenge in semantic segmentation. In this work to alleviate this problem we propose a novel Multi-Resolution Feature Perturbation (MRFP) technique to randomize domain-specific fine-grained features and perturb style of coarse features. Our experimental results on various urban-scene segmentation datasets clearly indicate that along with the perturbation of style-information perturbation of fine-feature components is paramount to learn domain invariant robust feature maps for semantic segmentation models. MRFP is a simple and computationally efficient transferable module with no additional learnable parameters or objective functions that helps state-of-the-art deep neural networks to learn robust domain invariant features for simulation-to-real semantic segmentation. Code is available at https://github.com/airl-iisc/MRFP.

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S-DyRF: Reference-Based Stylized Radiance Fields for Dynamic Scenes

Xingyi Li, Zhiguo Cao, Yizheng Wu, Kewei Wang, Ke Xian, Zhe Wang, Guosheng Lin

Current 3D stylization methods often assume static scenes which violates the dynamic nature of our real world. To address this limitation we present S-DyRF a reference-based spatio-temporal stylization method for dynamic neural radiance fields. However stylizing dynamic 3D scenes is inherently challenging due to the limited availability of stylized reference images along the temporal axis. Our key insight lies in introducing additional temporal cues besides the provided reference. To this end we generate temporal pseudo-references from the given stylized reference. These pseudo-references facilitate the propagation of style information from the reference to the entire dynamic 3D scene. For coarse style transfer we enforce novel views and times to mimic the style details present in pseudo-references at the feature level. To preserve high-frequency details we create a collection of stylized temporal pseudo-rays from temporal pseudo-references. These pseudo-rays serve as detailed and explicit stylization guidance for achieving fine style transfer. Experiments on both synthetic and real-world datasets demonstrate that our method yields plausible stylized results of space-time view synthesis on dynamic 3D scenes.

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MotionEditor: Editing Video Motion via Content-Aware Diffusion

http://arxiv.org/abs/2311.18830

Shuyuan Tu, Qi Dai, Zhi-Qi Cheng, Han Hu, Xintong Han, Zuxuan Wu, Yu-Gang Jiang

Existing diffusion-based video editing models have made gorgeous advances for editing attributes of a source video over time but struggle to manipulate the motion information while preserving the original protagonist's appearance and background. To address this we propose MotionEditor the first diffusion model for video motion editing. MotionEditor incorporates a novel content-aware motion adapter into ControlNet to capture temporal motion correspondence. While ControlNet enables direct generation based on skeleton poses it encounters challenges when modifying the source motion in the inverted noise due to contradictory signals between the noise (source) and the condition (reference). Our adapter complements ControlNet by involving source content to transfer adapted control signals seamlessly. Further we build up a two-branch architecture (a reconstruction branch and an editing branch) with a high-fidelity attention injection mechanism facilitating branch interaction. This mechanism enables the editing branch to query the key and value from the reconstruction branch in a decoupled manner making the editing branch retain the original background and protagonist appearance. We also propose a skeleton alignment algorithm to address the discrepancies in pose size and position. Experiments demonstrate the promising motion editing ability of MotionEditor both qualitatively and quantitatively. To the best of our knowledge MotionEditor is the first to use diffusion models specifically for video motion editing considering the origin dynamic background and camera movement.

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What How and When Should Object Detectors Update in Continually Changing Test Domains?

http://arxiv.org/abs/2312.08875

Jayeon Yoo, Dongkwan Lee, Inseop Chung, Donghyun Kim, Nojun Kwak

It is a well-known fact that the performance of deep learning models deteriorates when they encounter a distribution shift at test time. Test-time adaptation (TTA) algorithms have been proposed to adapt the model online while inferring test data. However existing research predominantly focuses on classification tasks through the optimization of batch normalization layers or classification heads but this approach limits its applicability to various model architectures like Transformers and makes it challenging to apply to other tasks such as object detection. In this paper we propose a novel online adaption approach for object detection in continually changing test domains considering which part of the model to update how to update it and when to perform the update. By introducing architecture-agnostic and lightweight adaptor modules and only updating these while leaving the pre-trained backbone unchanged we can rapidly adapt to new test domains in an efficient way and prevent catastrophic forgetting. Furthermore we present a practical and straightforward class-wise feature aligning method for object detection to resolve domain shifts. Additionally we enhance efficiency by determining when the model is sufficiently adapted or when additional adaptation is needed due to changes in the test distribution. Our approach surpasses baselines on widely used benchmarks achieving improvements of up to 4.9%p and 7.9%p in mAP for COCO ? COCO-corrupted and SHIFT respectively while maintaining about 20 FPS or higher. The implementation code is available at https://github.com/natureyoo/ContinualTTA_ObjectDetection.

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One-Prompt to Segment All Medical Images

http://arxiv.org/abs/2305.10300

Junde Wu, Min Xu

Large foundation models known for their strong zero-shot generalization have excelled in visual and language applications. However applying them to medical image segmentation a domain with diverse imaging types and target labels remains an open challenge. Current approaches such as adapting interactive segmentation models like Segment Anything Model (SAM) require user prompts for each sample during inference. Alternatively transfer learning methods like few/one-shot models demand labeled samples leading to high costs. This paper introduces a new paradigm toward the universal medical image segmentation termed 'One-Prompt Segmentation.' One-Prompt Segmentation combines the strengths of one-shot and interactive methods. In the inference stage with just one prompted sample it can adeptly handle the unseen task in a single forward pass. We train One-Prompt Model on 64 open-source medical datasets accompanied by the collection of over 3000 clinician-labeled prompts. Tested on 14 previously unseen datasets the One-Prompt Model showcases superior zero-shot segmentation capabilities outperforming a wide range of related methods. The code and data is released as https://github.com/KidsWithTokens/one-prompt.

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Bayesian Exploration of Pre-trained Models for Low-shot Image Classification

http://arxiv.org/abs/2404.00312

Yibo Miao, Yu Lei, Feng Zhou, Zhijie Deng

Low-shot image classification is a fundamental task in computer vision and the emergence of large-scale vision-language models such as CLIP has greatly advanced the forefront of research in this field. However most existing CLIP-based methods lack the flexibility to effectively incorporate other pre-trained models that encompass knowledge distinct from CLIP. To bridge the gap this work proposes a simple and effective probabilistic model ensemble framework based on Gaussian processes which have previously demonstrated remarkable efficacy in processing small data. We achieve the integration of prior knowledge by specifying the mean function with CLIP and the kernel function with an ensemble of deep kernels built upon various pre-trained models. By regressing the classification label directly our framework enables analytical inference straightforward uncertainty quantification and principled hyper-parameter tuning. Through extensive experiments on standard benchmarks we demonstrate that our method consistently outperforms competitive ensemble baselines regarding predictive performance. Additionally we assess the robustness of our method and the quality of the yielded uncertainty estimates on out-of-distribution datasets. We also illustrate that our method despite relying on label regression still enjoys superior model calibration compared to most deterministic baselines.

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GROUNDHOG: Grounding Large Language Models to Holistic Segmentation

http://arxiv.org/abs/2402.16846

Yichi Zhang, Ziqiao Ma, Xiaofeng Gao, Suhaila Shakiah, Qiaozi Gao, Joyce Chai

Most multimodal large language models (MLLMs) learn language-to-object grounding through causal language modeling where grounded objects are captured by bounding boxes as sequences of location tokens. This paradigm lacks pixel-level representations that are important for fine-grained visual understanding and diagnosis. In this work we introduce GROUNDHOG an MLLM developed by grounding Large Language Models to holistic segmentation. GROUNDHOG incorporates a masked feature extractor and converts extracted features into visual entity tokens for the MLLM backbone which then connects groundable phrases to unified grounding masks by retrieving and merging the entity masks. To train GROUNDHOG we carefully curated M3G2 a grounded visual instruction tuning dataset with Multi-Modal Multi-Grained Grounding by harvesting a collection of segmentation-grounded datasets with rich annotations. Our experimental results show that GROUNDHOG achieves superior performance on various language grounding tasks without task-specific fine-tuning and significantly reduces object hallucination. GROUNDHOG also demonstrates better grounding towards complex forms of visual input and provides easy-to-understand diagnosis in failure cases.

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Doubly Abductive Counterfactual Inference for Text-based Image Editing

http://arxiv.org/abs/2403.02981

Xue Song, Jiequan Cui, Hanwang Zhang, Jingjing Chen, Richang Hong, Yu-Gang Jiang

We study text-based image editing (TBIE) of a single image by counterfactual inference because it is an elegant formulation to precisely address the requirement: the edited image should retain the fidelity of the original one. Through the lens of the formulation we find that the crux of TBIE is that existing techniques hardly achieve a good trade-off between editability and fidelity mainly due to the overfitting of the single-image fine-tuning. To this end we propose a Doubly Abductive Counterfactual inference framework (DAC). We first parameterize an exogenous variable as a UNet LoRA whose abduction can encode all the image details. Second we abduct another exogenous variable parameterized by a text encoder LoRA which recovers the lost editability caused by the overfitted first abduction. Thanks to the second abduction which exclusively encodes the visual transition from post-edit to pre-edit its inversion---subtracting the LoRA---effectively reverts pre-edit back to post-edit thereby accomplishing the edit. Through extensive experiments our DAC achieves a good trade-off between editability and fidelity. Thus we can support a wide spectrum of user editing intents including addition removal manipulation replacement style transfer and facial change which are extensively validated in both qualitative and quantitative evaluations. Codes are in https://github.com/xuesong39/DAC.

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