CVPR 2024 Papers

Novelty detection is a critical task for deploying machine learning models in the open world. A crucial property of novelty detection methods is universality which can be interpreted as generalization across various distributions of training or test data. More precisely for novelty detection distribution shifts may occur in the training set or the test set. Shifts in the training set refer to cases where we train a novelty detector on a new dataset and expect strong transferability. Conversely distribution shifts in the test set indicate the methods' performance when the trained model encounters a shifted test sample. We experimentally show that existing methods falter in maintaining universality which stems from their rigid inductive biases. Motivated by this we aim for more generalized techniques that have more adaptable inductive biases. In this context we leverage the fact that contrastive learning provides an efficient framework to easily switch and adapt to new inductive biases through the proper choice of augmentations in forming the negative pairs. We propose a novel probabilistic auto-negative pair generation method AutoAugOOD along with contrastive learning to yield a universal novelty detector method. Our experiments demonstrate the superiority of our method under different distribution shifts in various image benchmark datasets. Notably our method emerges universality in the lens of adaptability to different setups of novelty detection including one-class unlabeled multi-class and labeled multi-class settings.

We present UnionFormer a novel framework that integrates tampering clues across three views by unified learning for image manipulation detection and localization. Specifically we construct a BSFI-Net to extract tampering features from RGB and noise views achieving enhanced responsiveness to boundary artifacts while modulating spatial consistency at different scales. Additionally to explore the inconsistency between objects as a new view of clues we combine object consistency modeling with tampering detection and localization into a three-task unified learning process allowing them to promote and improve mutually. Therefore we acquire a unified manipulation discriminative representation under multi-scale supervision that consolidates information from three views. This integration facilitates highly effective concurrent detection and localization of tampering. We perform extensive experiments on diverse datasets and the results show that the proposed approach outperforms state-of-the-art methods in tampering detection and localization.

Most models of visual attention aim at predicting either top-down or bottom-up control as studied using different visual search and free-viewing tasks. In this paper we propose the Human Attention Transformer (HAT) a single model that predicts both forms of attention control. HAT uses a novel transformer-based architecture and a simplified foveated retina that collectively create a spatio-temporal awareness akin to the dynamic visual working memory of humans. HAT not only establishes a new state-of-the-art in predicting the scanpath of fixations made during target-present and target-absent visual search and "taskless" free viewing but also makes human gaze behavior interpretable. Unlike previous methods that rely on a coarse grid of fixation cells and experience information loss due to fixation discretization HAT features a sequential dense prediction architecture and outputs a dense heatmap for each fixation thus avoiding discretizing fixations. HAT sets a new standard in computational attention which emphasizes effectiveness generality and interpretability. HAT's demonstrated scope and applicability will likely inspire the development of new attention models that can better predict human behavior in various attention-demanding scenarios. Code is available at https://github.com/cvlab-stonybrook/HAT.

This work delves into the task of pose-free novel view synthesis from stereo pairs a challenging and pioneering task in 3D vision. Our innovative framework unlike any before seamlessly integrates 2D correspondence matching camera pose estimation and NeRF rendering fostering a synergistic enhancement of these tasks. We achieve this through designing an architecture that utilizes a shared representation which serves as a foundation for enhanced 3D geometry understanding. Capitalizing on the inherent interplay between the tasks our unified framework is trained end-to-end with the proposed training strategy to improve overall model accuracy. Through extensive evaluations across diverse indoor and outdoor scenes from two real-world datasets we demonstrate that our approach achieves substantial improvement over previous methodologies especially in scenarios characterized by extreme viewpoint changes and the absence of accurate camera poses.

Automatic and interactive matting largely improve image matting by respectively alleviating the need for auxiliary input and enabling object selection. Due to different settings on whether prompts exist they either suffer from weakness in instance completeness or region details. Also when dealing with different scenarios directly switching between the two matting models introduces inconvenience and higher workload. Therefore we wonder whether we can alleviate the limitations of both settings while achieving unification to facilitate more convenient use. Our key idea is to offer saliency guidance for automatic mode to enable its attention to detailed regions and also refine the instance completeness in interactive mode by replacing the binary mask guidance with a more probabilistic form. With different guidance for each mode we can achieve unification through adaptable guidance defined as saliency information in automatic mode and user cue for interactive one. It is instantiated as candidate feature in our method an automatic switch for class token in pretrained ViTs and average feature of user prompts controlled by the existence of user prompts. Then we use the candidate feature to generate a probabilistic similarity map as the guidance to alleviate the over-reliance on binary mask. Extensive experiments show that our method can adapt well to both automatic and interactive scenarios with more light-weight framework. Code available at https://github.com/coconuthust/SmartMatting.

We present Unified-IO 2 a multimodal and multi-skill unified model capable of following novel instructions. Unified-IO 2 can use text images audio and/or videos as input and can generate text image or audio outputs which is accomplished in a unified way by tokenizing these different inputs and outputs into a shared semantic space that can then be processed by a single encoder-decoder transformer model. Unified-IO 2 is trained from scratch on a custom-built multimodal pre-training corpus and then learns an expansive set of skills through fine-tuning on over 120 datasets including datasets for segmentation object detection image editing audio localization video tracking embodied AI and 3D detection. To facilitate instruction-following we add prompts and other data augmentations to these tasks to allow Unified-IO 2 to generalize these skills to new tasks zero-shot. Unified-IO 2 is the first model to be trained on such a diverse and wide-reaching set of skills and unify three separate generation capabilities. Unified-IO 2 achieves state-of-the-art performance on the multi-task GRIT benchmark and achieves strong results on 30 diverse datasets including SEED-Bench image and video understanding TIFA image generation VQA 2.0 ScienceQA VIMA robotic manipulation VGG-Sound and Kinetics-Sounds and can perform unseen tasks and generate free-form responses. We release our model and code to facilitate future work.

This paper introduces Unified Language-driven Zero-shot Domain Adaptation (ULDA) a novel task setting that enables a single model to adapt to diverse target domains without explicit domain-ID knowledge. We identify the constraints in the existing language-driven zero-shot domain adaptation task particularly the requirement for domain IDs and domain-specific models which may restrict flexibility and scalability. To overcome these issues we propose a new framework for ULDA consisting of Hierarchical Context Alignment (HCA) Domain Consistent Representation Learning (DCRL) and Text-Driven Rectifier (TDR). These components work synergistically to align simulated features with target text across multiple visual levels retain semantic correlations between different regional representations and rectify biases between simulated and real target visual features respectively. Our extensive empirical evaluations demonstrate that this framework achieves competitive performance in both settings surpassing even the model that requires domain-ID showcasing its superiority and generalization ability. The proposed method is not only effective but also maintains practicality and efficiency as it does not introduce additional computational costs during inference. The code is available on the project website.

Test-time adaptation (TTA) aims at adapting a model pre-trained on the labeled source domain to the unlabeled target domain. Existing methods usually focus on improving TTA performance under covariate shifts while neglecting semantic shifts. In this paper we delve into a realistic open-set TTA setting where the target domain may contain samples from unknown classes. Many state-of-the-art closed-set TTA methods perform poorly when applied to open-set scenarios which can be attributed to the inaccurate estimation of data distribution and model confidence. To address these issues we propose a simple but effective framework called unified entropy optimization (UniEnt) which is capable of simultaneously adapting to covariate-shifted in-distribution (csID) data and detecting covariate-shifted out-of-distribution (csOOD) data. Specifically UniEnt first mines pseudo-csID and pseudo-csOOD samples from test data followed by entropy minimization on the pseudo-csID data and entropy maximization on the pseudo-csOOD data. Furthermore we introduce UniEnt+ to alleviate the noise caused by hard data partition leveraging sample-level confidence. Extensive experiments on CIFAR benchmarks and Tiny-ImageNet-C show the superiority of our framework. The code is available at https://github.com/gaozhengqing/UniEnt.

Despite the recent advances in unified image segmentation (IS) developing a unified video segmentation (VS) model remains a challenge. This is mainly because generic category-specified VS tasks need to detect all objects and track them across consecutive frames while prompt-guided VS tasks require re-identifying the target with visual/text prompts throughout the entire video making it hard to handle the different tasks with the same architecture. We make an attempt to address these issues and present a novel unified VS architecture namely UniVS by using prompts as queries. UniVS averages the prompt features of the target from previous frames as its initial query to explicitly decode masks and introduces a target-wise prompt cross-attention layer in the mask decoder to integrate prompt features in the memory pool. By taking the predicted masks of entities from previous frames as their visual prompts UniVS converts different VS tasks into prompt-guided target segmentation eliminating the heuristic inter-frame matching process. Our framework not only unifies the different VS tasks but also naturally achieves universal training and testing ensuring robust performance across different scenarios. UniVS shows a commendable balance between performance and universality on 10 challenging VS benchmarks covering video instance semantic panoptic object and referring segmentation tasks. Code can be found at https://github.com/MinghanLi/UniVS.

Large-kernel convolutional neural networks (ConvNets) have recently received extensive research attention but two unresolved and critical issues demand further investigation. 1) The architectures of existing large-kernel ConvNets largely follow the design principles of conventional ConvNets or transformers while the architectural design for large-kernel ConvNets remains under-addressed. 2) As transformers have dominated multiple modalities it remains to be investigated whether ConvNets also have a strong universal perception ability in domains beyond vision. In this paper we contribute from two aspects. 1) We propose four architectural guidelines for designing large-kernel ConvNets the core of which is to exploit the essential characteristics of large kernels that distinguish them from small kernels - they can see wide without going deep. Following such guidelines our proposed large-kernel ConvNet shows leading performance in image recognition (ImageNet accuracy of 88.0% ADE20K mIoU of 55.6% and COCO box AP of 56.4%) demonstrating better performance and higher speed than the recent powerful competitors. 2) We discover large kernels are the key to unlocking the exceptional performance of ConvNets in domains where they were originally not proficient. With certain modality-related preprocessing approaches the proposed model achieves state-of-the-art performance on time-series forecasting and audio recognition tasks even without modality-specific customization to the architecture. All the code and models are publicly available on GitHub and Huggingface.

Parameter-efficient transfer learning (PETL) i.e. fine-tuning a small portion of parameters is an effective strategy for adapting pre-trained models to downstream domains. To further reduce the memory demand recent PETL works focus on the more valuable memory-efficient characteristic. In this paper we argue that the scalability adaptability and generalizability of state-of-the-art methods are hindered by structural dependency and pertinency on specific pre-trained backbones. To this end we propose a new memory-efficient PETL strategy Universal Parallel Tuning (UniPT) to mitigate these weaknesses. Specifically we facilitate the transfer process via a lightweight and learnable parallel network which consists of: 1) A parallel interaction module that decouples the sequential connections and processes the intermediate activations detachedly from the pre-trained network. 2) A confidence aggregation module that learns optimal strategies adaptively for integrating cross-layer features. We evaluate UniPT with different backbones (e.g. T5 VSEinfinity CLIP4Clip Clip-ViL and MDETR) on various vision-and-language and pure NLP tasks. Extensive ablations on 18 datasets have validated that UniPT can not only dramatically reduce memory consumption and outperform the best competitor but also achieve competitive performance over other plain PETL methods with lower training memory overhead. Our code is publicly available at: https://github.com/Paranioar/UniPT.

In the context of autonomous driving the significance of effective feature learning is widely acknowledged. While conventional 3D self-supervised pre-training methods have shown widespread success most methods follow the ideas originally designed for 2D images. In this paper we present UniPAD a novel self-supervised learning paradigm applying 3D volumetric differentiable rendering. UniPAD implicitly encodes 3D space facilitating the reconstruction of continuous 3D shape structures and the intricate appearance characteristics of their 2D projections. The flexibility of our method enables seamless integration into both 2D and 3D frameworks enabling a more holistic comprehension of the scenes. We manifest the feasibility and effectiveness of UniPAD by conducting extensive experiments on various 3D perception tasks. Our method significantly improves lidar- camera- and lidar-camera-based baseline by 9.1 7.7 and 6.9 NDS respectively. Notably our pre-training pipeline achieves 73.2 NDS for 3D object detection and 79.4 mIoU for 3D semantic segmentation on the nuScenes validation set achieving state-of-the-art results in comparison with previous methods.

LiDAR semantic segmentation (LSS) is a critical task in autonomous driving and has achieved promising progress. However prior LSS methods are conventionally investigated and evaluated on datasets within the same domain in clear weather. The robustness of LSS models in unseen scenes and all weather conditions is crucial for ensuring safety and reliability in real applications. To this end we propose UniMix a universal method that enhances the adaptability and generalizability of LSS models. UniMix first leverages physically valid adverse weather simulation to construct a Bridge Domain which serves to bridge the domain gap between the clear weather scenes and the adverse weather scenes. Then a Universal Mixing operator is defined regarding spatial intensity and semantic distributions to create the intermediate domain with mixed samples from given domains. Integrating the proposed two techniques into a teacher-student framework UniMix efficiently mitigates the domain gap and enables LSS models to learn weather-robust and domain-invariant representations. We devote UniMix to two main setups: 1) unsupervised domain adaption adapting the model from the clear weather source domain to the adverse weather target domain; 2) domain generalization learning a model that generalizes well to unseen scenes in adverse weather. Extensive experiments validate the effectiveness of UniMix across different tasks and datasets all achieving superior performance over state-of-the-art methods. The code will be released.

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.

Human image editing includes tasks like changing a person's pose their clothing or editing the image according to a text prompt. However prior work often tackles these tasks separately overlooking the benefit of mutual reinforcement from learning them jointly. In this paper we propose UniHuman a unified model that addresses multiple facets of human image editing in real-world settings. To enhance the model's generation quality and generalization capacity we leverage guidance from human visual encoders and introduce a lightweight pose-warping module that can exploit different pose representations accommodating unseen textures and patterns. Furthermore to bridge the disparity between existing human editing benchmarks with real-world data we curated 400K high-quality human image-text pairs for training and collected 2K human images for out-of-domain testing both encompassing diverse clothing styles backgrounds and age groups. Experiments on both in-domain and out-of-domain test sets demonstrate that UniHuman outperforms task-specific models by a significant margin. In user studies UniHuman is preferred by the users in an average of 77% of cases. Our project is available at https://github.com/NannanLi999/UniHuman.

Garment manipulation (e.g. unfolding folding and hanging clothes) is essential for future robots to accomplish home-assistant tasks while highly challenging due to the diversity of garment configurations geometries and deformations. Although able to manipulate similar shaped garments in a certain task previous works mostly have to design different policies for different tasks could not generalize to garments with diverse geometries and often rely heavily on human-annotated data. In this paper we leverage the property that garments in a certain category have similar structures and then learn the topological dense (point-level) visual correspondence among garments in the category level with different deformations in the self-supervised manner. The topological correspondence can be easily adapted to the functional correspondence to guide the manipulation policies for various downstream tasks within only one or few-shot demonstrations. Experiments over garments in 3 different categories on 3 representative tasks in diverse scenarios using one or two arms taking one or more steps inputting flat or messy garments demonstrate the effectiveness of our proposed method. Project page: https://warshallrho.github.io/unigarmentmanip.

This paper introduces a novel unified representation of diffusion models for image generation and segmentation. Specifically we use a colormap to represent entity-level masks addressing the challenge of varying entity numbers while aligning the representation closely with the image RGB domain. Two novel modules including the location-aware color palette and progressive dichotomy module are proposed to support our mask representation. On the one hand a location-aware palette guarantees the colors' consistency to entities' locations. On the other hand the progressive dichotomy module can efficiently decode the synthesized colormap to high-quality entity-level masks in a depth-first binary search without knowing the cluster numbers. To tackle the issue of lacking large-scale segmentation training data we employ an inpainting pipeline and then improve the flexibility of diffusion models across various tasks including inpainting image synthesis referring segmentation and entity segmentation. Comprehensive experiments validate the efficiency of our approach demonstrating comparable segmentation mask quality to state-of-the-art and adaptability to multiple tasks.

Accurate monocular metric depth estimation (MMDE) is crucial to solving downstream tasks in 3D perception and modeling. However the remarkable accuracy of recent MMDE methods is confined to their training domains. These methods fail to generalize to unseen domains even in the presence of moderate domain gaps which hinders their practical applicability. We propose a new model UniDepth capable of reconstructing metric 3D scenes from solely single images across domains. Departing from the existing MMDE methods UniDepth directly predicts metric 3D points from the input image at inference time without any additional information striving for a universal and flexible MMDE solution. In particular UniDepth implements a self-promptable camera module predicting dense camera representation to condition depth features. Our model exploits a pseudo-spherical output representation which disentangles camera and depth representations. In addition we propose a geometric invariance loss that promotes the invariance of camera-prompted depth features. Thorough evaluations on ten datasets in a zero-shot regime consistently demonstrate the superior performance of UniDepth even when compared with methods directly trained on the testing domains. Code and models are available at: github.com/lpiccinelli-eth/unidepth