CVPR 2024 论文列表

In this paper we propose an efficient data-driven solution to self-localization within a floorplan. Floorplan data is readily available long-term persistent and inherently robust to changes in the visual appearance. Our method does not require retraining per map and location or demand a large database of images of the area of interest. We propose a novel probabilistic model consisting of an observation and a novel temporal filtering module. Operating internally with an efficient ray-based representation the observation module consists of a single and a multiview module to predict horizontal depth from images and fuses their results to benefit from advantages offered by either methodology. Our method operates on conventional consumer hardware and overcomes a common limitation of competing methods that often demand upright images. Our full system meets real-time requirements while outperforming the state-of-the-art by a significant margin.

Is vision good enough for language? Recent advancements in multimodal models primarily stem from the powerful reasoning abilities of large language models (LLMs). However the visual component typically depends only on the instance-level contrastive language-image pre-training (CLIP). Our research reveals that the visual capabilities in recent MultiModal LLMs (MLLMs) still exhibit systematic shortcomings. To understand the roots of these errors we explore the gap between the visual embedding space of CLIP and vision-only self-supervised learning. We identify "CLIP-blind pairs" - images that CLIP perceives as similar despite their clear visual differences. With these pairs we construct the Multimodal Visual Patterns (MMVP) benchmark. MMVP exposes areas where state-of-the-art systems including GPT-4V struggle with straightforward questions across nine basic visual patterns often providing incorrect answers and hallucinated explanations. We further evaluate various CLIP-based vision-and-language models and found a notable correlation between visual patterns that challenge CLIP models and those problematic for multimodal LLMs. As an initial effort to address these issues we propose a Mixture of Features (MoF) approach demonstrating that integrating vision self-supervised learning features with MLLMs can significantly enhance their visual grounding capabilities. Together our research suggests visual representation learning remains an open challenge and accurate visual grounding is crucial for future successful multimodal systems.

This paper introduces a novel approach to learning instance segmentation using extreme points i.e. the topmost leftmost bottommost and rightmost points of each object. These points are readily available in the modern bounding box annotation process while offering strong clues for precise segmentation and thus allows to improve performance at the same annotation cost with box-supervised methods. Our work considers extreme points as a part of the true instance mask and propagates them to identify potential foreground and background points which are all together used for training a pseudo label generator. Then pseudo labels given by the generator are in turn used for supervised learning of our final model. On three public benchmarks our method significantly outperforms existing box-supervised methods further narrowing the gap with its fully supervised counterpart. In particular our model generates high-quality masks when a target object is separated into multiple parts where previous box-supervised methods often fail.

We propose ExtraNeRF a novel method for extrapolating the range of views handled by a Neural Radiance Field (NeRF). Our main idea is to leverage NeRFs to model scene-specific fine-grained details while capitalizing on diffusion models to extrapolate beyond our observed data. A key ingredient is to track visibility to determine what portions of the scene have not been observed and focus on reconstructing those regions consistently with diffusion models. Our primary contributions include a visibility-aware diffusion-based inpainting module that is fine-tuned on the input imagery yielding an initial NeRF with moderate quality (often blurry) inpainted regions followed by a second diffusion model trained on the input imagery to consistently enhance notably sharpen the inpainted imagery from the first pass. We demonstrate high-quality results extrapolating beyond a small number of (typically six or fewer) input views effectively outpainting the NeRF as well as inpainting newly disoccluded regions inside the original viewing volume. We compare with related work both quantitatively and qualitatively and show significant gains over prior art.

Registration of point clouds collected from a pair of distant vehicles provides a comprehensive and accurate 3D view of the driving scenario which is vital for driving safety related applications yet existing literature suffers from the expensive pose label acquisition and the deficiency to generalize to new data distributions. In this paper we propose EYOC an unsupervised distant point cloud registration method that adapts to new point cloud distributions on the fly requiring no global pose labels. The core idea of EYOC is to train a feature extractor in a progressive fashion where in each round the feature extractor trained with near point cloud pairs can label slightly farther point cloud pairs enabling self-supervision on such far point cloud pairs. This process continues until the derived extractor can be used to register distant point clouds. Particularly to enable high-fidelity correspondence label generation we devise an effective spatial filtering scheme to select the most representative correspondences to register a point cloud pair and then utilize the aligned point clouds to discover more correct correspondences. Experiments show that EYOC can achieve comparable performance with state-of-the-art supervised methods at a lower training cost. Moreover it outwits supervised methods regarding generalization performance on new data distributions.

Video prediction is a challenging task due to its nature of uncertainty especially for forecasting a long period. To model the temporal dynamics advanced methods benefit from the recent success of diffusion models and repeatedly refine the predicted future frames with 3D spatiotemporal U-Net. However there exists a gap between the present and future and the repeated usage of U-Net brings a heavy computation burden. To address this we propose a diffusion-based video prediction method that predicts future frames by extrapolating the present distribution of features namely ExtDM. Specifically our method consists of three components: (i) a motion autoencoder conducts a bijection transformation between video frames and motion cues; (ii) a layered distribution adaptor module extrapolates the present features in the guidance of Gaussian distribution; (iii) a 3D U-Net architecture specialized for jointly fusing guidance and features among the temporal dimension by spatiotemporal-window attention. Extensive experiments on five popular benchmarks covering short- and long-term video prediction verify the effectiveness of ExtDM.

Although Multimodal Large Language Models (MLLMs) have demonstrated promising versatile capabilities their performance is still inferior to specialized models on downstream tasks which makes adaptation necessary to enhance their utility. However fine-tuning methods require independent training for every model leading to huge computation and memory overheads. In this paper we propose a novel setting where we aim to improve the performance of diverse MLLMs with a group of shared parameters optimized for a downstream task. To achieve this we propose Transferable Visual Prompting (TVP) a simple and effective approach to generate visual prompts that can transfer to different models and improve their performance on downstream tasks after trained on only one model. We introduce two strategies to address the issue of cross-model feature corruption of existing visual prompting methods and enhance the transferability of the learned prompts including 1) Feature Consistency Alignment: which imposes constraints to the prompted feature changes to maintain task-agnostic knowledge; 2) Task Semantics Enrichment: which encourages the prompted images to contain richer task-specific semantics with language guidance. We validate the effectiveness of TVP through extensive experiments with 6 modern MLLMs on a wide variety of tasks ranging from object recognition and counting to multimodal reasoning and hallucination correction.

Open-vocabulary human-object interaction (HOI) detection which is concerned with the problem of detecting novel HOIs guided by natural language is crucial for understanding human-centric scenes. However prior zero-shot HOI detectors often employ the same levels of feature maps to model HOIs with varying distances leading to suboptimal performance in scenes containing human-object pairs with a wide range of distances. In addition these detectors primarily rely on category names and overlook the rich contextual information that language can provide which is essential for capturing open vocabulary concepts that are typically rare and not well-represented by category names alone. In this paper we introduce a novel end-to-end open vocabulary HOI detection framework with conditional multi-level decoding and fine-grained semantic enhancement (CMD-SE) harnessing the potential of Visual-Language Models (VLMs). Specifically we propose to model human-object pairs with different distances with different levels of feature maps by incorporating a soft constraint during the bipartite matching process. Furthermore by leveraging large language models (LLMs) such as GPT models we exploit their extensive world knowledge to generate descriptions of human body part states for various interactions. Then we integrate the generalizable and fine-grained semantics of human body parts to improve interaction recognition. Experimental results on two datasets SWIG-HOI and HICO-DET demonstrate that our proposed method achieves state-of-the-art results in open vocabulary HOI detection. The code and models are available at https://github.com/ltttpku/CMD-SE-release.

To build a cross-modal latent space between 3D human motion and language acquiring large-scale and high-quality human motion data is crucial. However unlike the abundance of image data the scarcity of motion data has limited the performance of existing motion-language models. To counter this we introduce "motion patches" a new representation of motion sequences and propose using Vision Transformers (ViT) as motion encoders via transfer learning aiming to extract useful knowledge from the image domain and apply it to the motion domain. These motion patches created by dividing and sorting skeleton joints based on body parts in motion sequences are robust to varying skeleton structures and can be regarded as color image patches in ViT. We find that transfer learning with pre-trained weights of ViT obtained through training with 2D image data can boost the performance of motion analysis presenting a promising direction for addressing the issue of limited motion data. Our extensive experiments show that the proposed motion patches used jointly with ViT achieve state-of-the-art performance in the benchmarks of text-to-motion retrieval and other novel challenging tasks such as cross-skeleton recognition zero-shot motion classification and human interaction recognition which are currently impeded by the lack of data.

CLIP has demonstrated marked progress in visual recognition due to its powerful pre-training on large-scale image-text pairs. However it still remains a critical challenge: how to transfer image-level knowledge into pixel-level understanding tasks such as semantic segmentation. In this paper to solve the mentioned challenge we analyze the gap between the capability of the CLIP model and the requirement of the zero-shot semantic segmentation task. Based on our analysis and observations we propose a novel method for zero-shot semantic segmentation dubbed CLIP-RC (CLIP with Regional Clues) bringing two main insights. On the one hand a region-level bridge is necessary to provide fine-grained semantics. On the other hand overfitting should be mitigated during the training stage. Benefiting from the above discoveries CLIP-RC achieves state-of-the-art performance on various zero-shot semantic segmentation benchmarks including PASCAL VOC PASCAL Context and COCO-Stuff 164K. Code will be available at https://github.com/Jittor/JSeg.

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.

Human-Object Interaction (HOI) detection plays a crucial role in visual scene comprehension. In recent advancements two-stage detectors have taken a prominent position. However they are encumbered by two primary challenges. First the misalignment between feature representation and relation reasoning gives rise to a deficiency in discriminative features crucial for interaction detection. Second due to sparse annotation the second-stage interaction head generates numerous candidate <human object> pairs with only a small fraction receiving supervision. Towards these issues we propose a hybrid learning method based on pose-aware HOI feature refinement. Specifically we devise pose-aware feature refinement that encodes spatial features by considering human body pose characteristics. It can direct attention towards key regions ultimately offering a wealth of fine-grained features imperative for HOI detection. Further we introduce a hybrid learning method that combines HOI triplets with probabilistic soft labels supervision which is regenerated from decoupled verb-object pairs. This method explores the implicit connections between the interactions enhancing model generalization without requiring additional data. Our method establishes state-of-the-art performance on HICO-DET benchmark and excels notably in detecting rare HOIs.

Open world object detection aims to identify objects of unseen categories and incrementally recognize them once their annotations are provided. In distinction to the traditional paradigm that is limited to predefined categories this setting promises a continual and generalizable way of estimating objectness using class-agnostic information. However achieving such decorrelation between objectness and class information proves challenging. Without explicit consideration existing methods usually exhibit low recall on unknown objects and can misclassify them into known classes. To address this problem we exploit three levels of orthogonality in the detection process: First the objectness and classification heads are disentangled by operating on separate sets of features that are orthogonal to each other in a devised polar coordinate system. Secondly a prediction decorrelation loss is introduced to guide the detector towards more general and class-independent prediction. Furthermore we propose a calibration scheme that helps maintain orthogonality throughout the training process to mitigate catastrophic interference and facilitate incremental learning of previously unseen objects. Our method is comprehensively evaluated on open world and incremental object detection benchmarks demonstrating its effectiveness in detecting both known and unknown objects. Code and models are available at https://github.com/feifeiobama/OrthogonalDet.

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.

This paper presents a new approach for the detection of fake videos based on the analysis of style latent vectors and their abnormal behavior in temporal changes in the generated videos. We discovered that the generated facial videos suffer from the temporal distinctiveness in the temporal changes of style latent vectors which are inevitable during the generation of temporally stable videos with various facial expressions and geometric transformations. Our framework utilizes the StyleGRU module trained by contrastive learning to represent the dynamic properties of style latent vectors. Additionally we introduce a style attention module that integrates StyleGRU-generated features with content-based features enabling the detection of visual and temporal artifacts. We demonstrate our approach across various benchmark scenarios in deepfake detection showing its superiority in cross-dataset and cross-manipulation scenarios. Through further analysis we also validate the importance of using temporal changes of style latent vectors to improve the generality of deepfake video detection.

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

Contents generated by recent advanced Text-to-Image (T2I) diffusion models are sometimes too imaginative for existing off-the-shelf dense predictors to estimate due to the immitigable domain gap. We introduce DMP a pipeline utilizing pre-trained T2I models as a prior for dense prediction tasks. To address the misalignment between deterministic prediction tasks and stochastic T2I models we reformulate the diffusion process through a sequence of interpolations establishing a deterministic mapping between input RGB images and output prediction distributions. To preserve generalizability we use low-rank adaptation to fine-tune pre-trained models. Extensive experiments across five tasks including 3D property estimation semantic segmentation and intrinsic image decomposition showcase the efficacy of the proposed method. Despite limited-domain training data the approach yields faithful estimations for arbitrary images surpassing existing state-of-the-art algorithms.

The many variations of Implicit Neural Representations (INRs) where a neural network is trained as a continuous representation of a signal have tremendous practical utility for downstream tasks including novel view synthesis video compression and image super-resolution. Unfortunately the inner workings of these networks are seriously understudied. Our work eXplaining the Implicit Neural Canvas (XINC) is a unified framework for explaining properties of INRs by examining the strength of each neuron's contribution to each output pixel. We call the aggregate of these contribution maps the Implicit Neural Canvas and we use this concept to demonstrate that the INRs we study learn to "see" the frames they represent in surprising ways. For example INRs tend to have highly distributed representations. While lacking high-level object semantics they have a significant bias for color and edges and are almost entirely space-agnostic. We arrive at our conclusions by examining how objects are represented across time in video INRs using clustering to visualize similar neurons across layers and architectures and show that this is dominated by motion. These insights demonstrate the general usefulness of our analysis framework.

Large multi-modal models (LMMs) hold the potential to usher in a new era of automated visual assistance for people who are blind or low vision (BLV). Yet these models have not been systematically evaluated on data captured by BLV users. We address this by empirically assessing CLIP a widely-used LMM likely to underpin many assistive technologies. Testing 25 CLIP variants in a zero-shot classification task we find that their accuracy is 15 percentage points lower on average for images captured by BLV users than web-crawled images. This disparity stems from CLIP's sensitivities to 1) image content (e.g. not recognizing disability objects as well as other objects); 2) image quality (e.g. not being robust to lighting variation); and 3) text content (e.g. not recognizing objects described by tactile adjectives as well as visual ones). We delve deeper with a textual analysis of three common pre-training datasets: LAION-400M LAION-2B and DataComp-1B showing that disability content is rarely mentioned. We then provide three examples that illustrate how the performance disparities extend to three downstream models underpinned by CLIP: OWL-ViT CLIPSeg and DALL-E2. We find that few-shot learning with as few as 5 images can mitigate CLIP's quality-of-service disparities for BLV users in some scenarios which we discuss alongside a set of other possible mitigations.