CVPR 2024 Papers

Vision graph neural networks (ViG) offer a new avenue for exploration in computer vision. A major bottleneck in ViGs is the inefficient k-nearest neighbor (KNN) operation used for graph construction. To solve this issue we propose a new method for designing ViGs Dynamic Axial Graph Construction (DAGC) which is more efficient than KNN as it limits the number of considered graph connections made within an image. Additionally we propose a novel CNN-GNN architecture GreedyViG which uses DAGC. Extensive experiments show that GreedyViG beats existing ViG CNN and ViT architectures in terms of accuracy GMACs and parameters on image classification object detection instance segmentation and semantic segmentation tasks. Our smallest model GreedyViG-S achieves 81.1% top-1 accuracy on ImageNet-1K 2.9% higher than Vision GNN and 2.2% higher than Vision HyperGraph Neural Network (ViHGNN) with less GMACs and a similar number of parameters. Our largest model GreedyViG-B obtains 83.9% top-1 accuracy 0.2% higher than Vision GNN with a 66.6% decrease in parameters and a 69% decrease in GMACs. GreedyViG-B also obtains the same accuracy as ViHGNN with a 67.3% decrease in parameters and a 71.3% decrease in GMACs. Our work shows that hybrid CNN-GNN architectures not only provide a new avenue for designing efficient models but that they can also exceed the performance of current state-of-the-art models.

Prompt learning in pretrained visual-language models has shown remarkable flexibility across various downstream tasks. Leveraging its inherent lightweight nature recent research attempted to integrate the powerful pretrained models into federated learning frameworks to simultaneously reduce communication costs and promote local training on insufficient data. Despite these efforts current federated prompt learning methods lack specialized designs to systematically address severe data heterogeneities e.g. data distribution with both label and feature shifts involved. To address this challenge we present Federated Prompts Cooperation via Optimal Transport (FedOTP) which introduces efficient collaborative prompt learning strategies to capture diverse category traits on a per-client basis. Specifically for each client we learn a global prompt to extract consensus knowledge among clients and a local prompt to capture client-specific category characteristics. Unbalanced Optimal Transport is then employed to align local visual features with these prompts striking a balance between global consensus and local personalization. By relaxing one of the equality constraints FedOTP enables prompts to focus solely on core image patch regions. Extensive experiments on datasets with various types of heterogeneities have demonstrated that our FedOTP outperforms the state-of-the-art methods.

Large multimodal models (LMMs) have evolved from large language models (LLMs) to integrate multiple input modalities such as visual inputs. This integration augments the capacity of LLMs for tasks requiring visual comprehension and reasoning. However the extent and limitations of their enhanced abilities are not fully understood especially when it comes to real-world tasks. To address this gap we introduce GlitchBench a novel benchmark derived from video game quality assurance tasks to test and evaluate the reasoning capabilities of LMMs. Our benchmark is curated from a variety of unusual and glitched scenarios from video games and aims to challenge both the visual and linguistic reasoning powers of LMMs in detecting and interpreting out-of-the-ordinary events. We evaluate multiple state-of-the-art LMMs and we show that GlitchBench presents a new challenge for these models. Code and data are available at: https://glitchbench.github.io/

Zero-shot 3D point cloud understanding can be achieved via 2D Vision-Language Models (VLMs). Existing strategies directly map VLM representations from 2D pixels of rendered or captured views to 3D points overlooking the inherent and expressible point cloud geometric structure. Geometrically similar or close regions can be exploited for bolstering point cloud understanding as they are likely to share semantic information. To this end we introduce the first training-free aggregation technique that leverages the point cloud's 3D geometric structure to improve the quality of the transferred VLM representation. Our approach operates iteratively performing local-to-global aggregation based on geometric and semantic point-level reasoning. We benchmark our approach on three downstream tasks including classification part segmentation and semantic segmentation with a variety of datasets representing both synthetic/real-world and indoor/outdoor scenarios. Our approach achieves new state-of-the-art results in all benchmarks.

Recent advancements in Large Vision-Language Models (VLMs) have shown great promise in natural image domains allowing users to hold a dialogue about given visual content. However such general-domain VLMs perform poorly for Remote Sensing (RS) scenarios leading to inaccurate or fabricated information when presented with RS domain-specific queries. Such a behavior emerges due to the unique challenges introduced by RS imagery. For example to handle high-resolution RS imagery with diverse scale changes across categories and many small objects region-level reasoning is necessary alongside holistic scene interpretation. Furthermore the lack of domain-specific multimodal instruction following data as well as strong backbone models for RS make it hard for the models to align their behavior with user queries. To address these limitations we propose GeoChat - the first versatile remote sensing VLM that offers multitask conversational capabilities with high-resolution RS images. Specifically GeoChat can not only answer image-level queries but also accepts region inputs to hold region-specific dialogue. Furthermore it can visually ground objects in its responses by referring to their spatial coordinates. To address the lack of domain-specific datasets we generate a novel RS multimodal instruction-following dataset by extending image-text pairs from existing diverse RS datasets. Leveraging this rich dataset we fine-tune our remote sensing VLM based on the LLaVA-1.5 architecture. We establish a comprehensive benchmark for RS multitask conversations and compare with a number of baseline methods. GeoChat demonstrates robust zero-shot performance on various remote sensing tasks e.g. image and region captioning visual question answering scene classification visually grounded conversations and referring object detection. Our codes will be open-sourced.

Real-world vision tasks frequently suffer from the appearance of unexpected adverse weather conditions including rain haze snow and raindrops. In the last decade convolutional neural networks and vision transformers have yielded outstanding results in single-weather video removal. However due to the absence of appropriate adaptation most of them fail to generalize to other weather conditions. Although ViWS-Net is proposed to remove adverse weather conditions in videos with a single set of pre-trained weights it is seriously blinded by seen weather at train-time and degenerates when coming to unseen weather during test-time. In this work we introduce test-time adaptation into adverse weather removal in videos and propose the first framework that integrates test-time adaptation into the iterative diffusion reverse process. Specifically we devise a diffusion-based network with a novel temporal noise model to efficiently explore frame-correlated information in degraded video clips at training stage. During inference stage we introduce a proxy task named Diffusion Tubelet Self-Calibration to learn the primer distribution of test video stream and optimize the model by approximating the temporal noise model for online adaptation. Experimental results on benchmark datasets demonstrate that our Test-Time Adaptation method with Diffusion-based network(Diff-TTA) outperforms state-of-the-art methods in terms of restoring videos degraded by seen weather conditions. Its generalizable capability is validated with unseen weather conditions in synthesized and real-world videos.

Humans can easily solve multimodal tasks in context with only a few demonstrations or simple instructions which current multimodal systems largely struggle to imitate. In this work we demonstrate that by effectively scaling up generative multimodal models their task-agnostic in-context learning capabilities can be significantly enhanced. We introduce Emu2 a generative multimodal model with 37 billion parameters which serves as a base model and general-purpose interface for a variety of multimodal tasks. Emu2 not only achieves strong performance in few-shot setting but can also be instruct-tuned to follow specific instructions such as visual question answering and object-grounded image generation. Emu2 even emerges to solve tasks that require on-the-fly reasoning such as visual prompting which existing models are unlikely to handle. We identify additional tasks where Emu2's in-context learning can further improve and discuss its broader societal impact. Our code and models will be made publicly available to facilitate future research.

Most existing image compression approaches perform transform coding in the pixel space to reduce its spatial redundancy. However they encounter difficulties in achieving both high-realism and high-fidelity at low bitrate as the pixel-space distortion may not align with human perception. To address this issue we introduce a Generative Latent Coding (GLC) architecture which performs transform coding in the latent space of a generative vector-quantized variational auto-encoder (VQ-VAE) instead of in the pixel space. The generative latent space is characterized by greater sparsity richer semantic and better alignment with human perception rendering it advantageous for achieving high-realism and high-fidelity compression. Additionally we introduce a categorical hyper module to reduce the bit cost of hyper-information and a code-prediction-based supervision to enhance the semantic consistency. Experiments demonstrate that our GLC maintains high visual quality with less than 0.04 bpp on natural images and less than 0.01 bpp on facial images. On the CLIC2020 test set we achieve the same FID as MS-ILLM with 45% fewer bits. Furthermore the powerful generative latent space enables various applications built on our GLC pipeline such as image restoration and style transfer.

Robotics agents often struggle to understand and follow the multi-modal prompts in complex manipulation scenes which are challenging to be sufficiently and accurately described by text alone. Moreover for long-horizon manipulation tasks the deviation from general instruction tends to accumulate if lack of intermediate guidance from high-level subgoals. For this we consider can we generate subgoal images before act to enhance the instruction following in long-horizon manipulation with multi-modal prompts? Inspired by the great success of diffusion model in image generation tasks we propose a novel hierarchical framework named as CoTDiffusion that incorporates diffusion model as a high-level planner to convert the general and multi-modal prompts into coherent visual subgoal plans which further guide the low-level policy model before action execution. We design a semantic alignment module that can anchor the progress of generated keyframes along a coherent generation chain unlocking the chain-of-thought reasoning ability of diffusion model. Additionally we propose bi-directional generation and frame concat mechanism to further enhance the fidelity of generated subgoal images and the accuracy of instruction following. The experiments cover various robotics manipulation scenarios including visual reasoning visual rearrange and visual constraints. CoTDiffusion achieves outstanding performance gain compared to the baselines without explicit subgoal generation which proves that a subgoal image is worth a thousand words of instruction.

Whole Slide Image (WSI) classification is often formulated as a Multiple Instance Learning (MIL) problem. Recently Vision-Language Models (VLMs) have demonstrated remarkable performance in WSI classification. However existing methods leverage coarse-grained pathogenetic descriptions for visual representation supervision which are insufficient to capture the complex visual appearance of pathogenetic images hindering the generalizability of models on diverse downstream tasks. Additionally processing high-resolution WSIs can be computationally expensive. In this paper we propose a novel "Fine-grained Visual-Semantic Interaction" (FiVE) framework for WSI classification. It is designed to enhance the model's generalizability by leveraging the interaction between localized visual patterns and fine-grained pathological semantics. Specifically with meticulously designed queries we start by utilizing a large language model to extract fine-grained pathological descriptions from various non-standardized raw reports. The output descriptions are then reconstructed into fine-grained labels used for training. By introducing a Task-specific Fine-grained Semantics (TFS) module we enable prompts to capture crucial visual information in WSIs which enhances representation learning and augments generalization capabilities significantly. Furthermore given that pathological visual patterns are redundantly distributed across tissue slices we sample a subset of visual instances during training. Our method demonstrates robust generalizability and strong transferability dominantly outperforming the counterparts on the TCGA Lung Cancer dataset with at least 9.19% higher accuracy in few-shot experiments. The code is available at: https://github.com/ls1rius/WSI_FiVE.

Can we synthesize 3D humans interacting with scenes without learning from any 3D human-scene interaction data? We propose GenZI the first zero-shot approach to generating 3D human-scene interactions. Key to GenZI is our distillation of interaction priors from large vision-language models (VLMs) which have learned a rich semantic space of 2D human-scene compositions. Given a natural language description and a coarse point location of the desired interaction in a 3D scene we first leverage VLMs to imagine plausible 2D human interactions inpainted into multiple rendered views of the scene. We then formulate a robust iterative optimization to synthesize the pose and shape of a 3D human model in the scene guided by consistency with the 2D interaction hypotheses. In contrast to existing learning-based approaches GenZI circumvents the conventional need for captured 3D interaction data and allows for flexible control of the 3D interaction synthesis with easy-to-use text prompts. Extensive experiments show that our zero-shot approach has high flexibility and generality making it applicable to diverse scene types including both indoor and outdoor environments.

Grounding referred objects in 3D scenes is a burgeoning vision-language task pivotal for propelling Embodied AI as it endeavors to connect the 3D physical world with free-form descriptions. Compared to the 2D counterparts challenges posed by the variability of 3D visual grounding remain relatively unsolved in existing studies: 1) the underlying geometric and complex spatial relationships in 3D scene. 2) the inherent complexity of 3D grounded language. 3) the inconsistencies between text and geometric features. To tackle these issues we propose G^3-LQ a DEtection TRansformer-based model tailored for 3D visual grounding task. G^3-LQ explicitly models Geometric-aware visual representations and Generates fine-Grained Language-guided object Queries in an overarching framework which comprises two dedicated modules. Specifically the Position Adaptive Geometric Exploring (PAGE) unearths underlying information of 3D objects in the geometric details and spatial relationships perspectives. The Fine-grained Language-guided Query Selection (Flan-QS) delves into syntactic structure of texts and generates object queries that exhibit higher relevance towards fine-grained text features. Finally a pioneering Poincare Semantic Alignment (PSA) loss establishes semantic-geometry consistencies by modeling non-linear vision-text feature mappings and aligning them on a hyperbolic prototype--Poincare ball. Extensive experiments verify the superiority of our G^3-LQ method trumping the state-of-the-arts by a considerable margin.

Generalized Referring Expression Segmentation (GRES) extends the scope of classic RES to refer to multiple objects in one expression or identify the empty targets absent in the image. GRES poses challenges in modeling the complex spatial relationships of the instances in the image and identifying non-existing referents. Multimodal Large Language Models (MLLMs) have recently shown tremendous progress in these complicated vision-language tasks. Connecting Large Language Models (LLMs) and vision models MLLMs are proficient in understanding contexts with visual inputs. Among them LISA as a representative adopts a special [SEG] token to prompt a segmentation mask decoder e.g. SAM to enable MLLMs in the RES task. However existing solutions to GRES remain unsatisfactory since current segmentation MLLMs cannot correctly handle the cases where users might reference multiple subjects in a singular prompt or provide descriptions incongruent with any image target. In this paper we propose Generalized Segmentation Vision Assistant (GSVA) to address this gap. Specifically GSVA reuses the [SEG] token to prompt the segmentation model towards supporting multiple mask references simultaneously and innovatively learns to generate a [REJ] token to reject the targets explicitly. Experiments validate GSVA's efficacy in resolving the GRES issue marking a notable enhancement and setting a new record on the GRES benchmark gRefCOCO dataset. GSVA also proves effective across various classic referring segmentation and comprehension tasks.

The increasing use of transformer-based large language models brings forward the challenge of processing long sequences. In document visual question answering (DocVQA) leading methods focus on the single-page setting while documents can span hundreds of pages. We present GRAM a method that seamlessly extends pre-trained single-page models to the multi-page setting without requiring computationally-heavy pretraining. To do so we leverage a single-page encoder for local page-level understanding and enhance it with document-level designated layers and learnable tokens facilitating the flow of information across pages for global reasoning. To enforce our model to utilize the newly introduced document tokens we propose a tailored bias adaptation method. For additional computational savings during decoding we introduce an optional compression stage using our compression-transformer (CFormer)reducing the encoded sequence length thereby allowing a tradeoff between quality and latency. Extensive experiments showcase GRAM's state-of-the-art performance on the benchmarks for multi-page DocVQA demonstrating the effectiveness of our approach.

Multimodal Large Language Models (MLLMs) have excelled in 2D image-text comprehension and image generation but their understanding of the 3D world is notably deficient limiting progress in 3D language understanding and generation. To solve this problem we introduce GPT4Point an innovative groundbreaking point-language multimodal model designed specifically for unified 3D object understanding and generation within the MLLM framework. GPT4Point as a powerful 3D MLLM seamlessly can execute a variety of point-text reference tasks such as point-cloud captioning and Q&A. Additionally GPT4Point is equipped with advanced capabilities for controllable 3D generation it can get high-quality results through a low-quality point-text feature maintaining the geometric shapes and colors. To support the expansive needs of 3D object-text pairs we develop Pyramid-XL a point-language dataset annotation engine. It constructs a large-scale database over 1M objects of varied text granularity levels from the Objaverse-XL dataset essential for training GPT4Point. A comprehensive benchmark has been proposed to evaluate 3D point-language understanding capabilities. In extensive evaluations GPT4Point has demonstrated superior performance in understanding and generation.

Recent advancements in vision-language foundation models have significantly enhanced open-vocabulary 3D scene understanding. However the generalizability of existing methods is constrained due to their framework designs and their reliance on 3D data. We address this limitation by introducing Generalizable Open-Vocabulary Neural Semantic Fields (GOV-NeSF) a novel approach offering a generalizable implicit representation of 3D scenes with open-vocabulary semantics. We aggregate the geometry-aware features using a cost volume and propose a Multi-view Joint Fusion module to aggregate multi-view features through a cross-view attention mechanism which effectively predicts view-specific blending weights for both colors and open-vocabulary features. Remarkably our GOV-NeSF exhibits state-of-the-art performance in both 2D and 3D open-vocabulary semantic segmentation eliminating the need for ground truth semantic labels or depth priors and effectively generalize across scenes and datasets without fine-tuning.

Large Multimodal Models (LMMs) extend Large Language Models to the vision domain. Initial LMMs used holistic images and text prompts to generate ungrounded textual responses. Recently region-level LMMs have been used to generate visually grounded responses. However they are limited to only referring to a single object category at a time require users to specify the regions or cannot offer dense pixel-wise object grounding. In this work we present Grounding LMM (GLaMM) the first model that can generate natural language responses seamlessly intertwined with corresponding object segmentation masks. GLaMM not only grounds objects appearing in the conversations but is flexible enough to accept both textual and optional visual prompts (region of interest) as input. This empowers users to interact with the model at various levels of granularity both in textual and visual domains. Due to the lack of standard benchmarks for the novel setting of visually Grounded Conversation Generation (GCG) we introduce a comprehensive evaluation protocol with our curated grounded conversations. Our proposed GCG task requires densely grounded concepts in natural scenes at a large-scale. To this end we propose a densely annotated Grounding-anything Dataset (GranD) using our proposed automated annotation pipeline that encompasses 7.5M unique concepts grounded in a total of 810M regions available with segmentation masks. Besides GCG GLaMM also performs effectively on several downstream tasks e.g. referring expression segmentation image and region-level captioning and vision-language conversations.

This paper proposes a GeneraLIst encoder-Decoder (GLID) pre-training method for better handling various downstream computer vision tasks. While self-supervised pre-training approaches e.g. Masked Autoencoder have shown success in transfer learning task-specific sub-architectures are still required to be appended for different downstream tasks which cannot enjoy the benefits of large-scale pre-training. GLID overcomes this challenge by allowing the pre-trained generalist encoder-decoder to be fine-tuned on various vision tasks with minimal task-specific architecture modifications. In the GLID training scheme pre-training pretext task and other downstream tasks are modeled as "query-to-answer" problems including the pre-training pretext task and other downstream tasks. We pre-train a task-agnostic encoder-decoder with query-mask pairs. During fine-tuning GLID maintains the pre-trained encoder-decoder and queries only replacing the topmost linear transformation layer with task-specific linear heads. This minimizes the pretrain-finetune architecture inconsistency and enables the pre-trained model to better adapt to downstream tasks. GLID achieves competitive performance on various vision tasks including object detection image segmentation pose estimation and depth estimation outperforming or matching specialist models such as Mask2Former DETR ViTPose and BinsFormer.

Training a linear classifier or lightweight model on top of pretrained vision model outputs so-called 'frozen features' leads to impressive performance on a number of downstream few-shot tasks. Currently frozen features are not modified during training. On the other hand when networks are trained directly on images data augmentation is a standard recipe that improves performance with no substantial overhead. In this paper we conduct an extensive pilot study on few-shot image classification that explores applying data augmentations in the frozen feature space dubbed 'frozen feature augmentation (FroFA)' covering twenty augmentations in total. Our study demonstrates that adopting a deceptively simple pointwise FroFA such as brightness can improve few-shot performance consistently across three network architectures three large pretraining datasets and eight transfer datasets.