CVPR2024/CVPR2024-papers-abstract-index huggingface dataset:
Computer vision techniques play a central role in the perception stack of autonomous vehicles. Such methods are employed to perceive the vehicle surroundings given sensor data. 3D LiDAR sensors are commonly used to collect sparse 3D point clouds from the scene. However compared to human perception such systems struggle to deduce the unseen parts of the scene given those sparse point clouds. In this matter the scene completion task aims at predicting the gaps in the LiDAR measurements to achieve a more complete scene representation. Given the promising results of recent diffusion models as generative models for images we propose extending them to achieve scene completion from a single 3D LiDAR scan. Previous works used diffusion models over range images extracted from LiDAR data directly applying image-based diffusion methods. Distinctly we propose to directly operate on the points reformulating the noising and denoising diffusion process such that it can efficiently work at scene scale. Together with our approach we propose a regularization loss to stabilize the noise predicted during the denoising process. Our experimental evaluation shows that our method can complete the scene given a single LiDAR scan as input producing a scene with more details compared to state-of-the-art scene completion methods.
Together with our approach we propose a regularization loss to stabilize the noise predicted during the denoising process. Our experimental evaluation shows that our method can complete the scene given a single LiDAR scan as input producing a scene with more details compared to state-of-the-art scene completion methods. We believe that our proposed diffusion process formulation can support further research in diffusion models applied to scene-scale point cloud data.
Source-free domain adaptation (SFDA) assumes that model adaptation only accesses the well-learned source model and unlabeled target instances for knowledge transfer. However cross-domain distribution shift easily triggers invalid discriminative semantics from source model on recognizing the target samples. Hence understanding the specific content of discriminative pattern and adjusting their representation in target domain become the important key to overcome SFDA. To achieve such a vision this paper proposes a novel explanation paradigm "Discriminative Pattern Calibration (DPC)" mechanism on solving SFDA issue. Concretely DPC first utilizes learning network to infer the discriminative regions on the target images and specifically emphasizes them in feature space to enhance their representation. Moreover DPC relies on the attention-reversed mixup mechanism to augment more samples and improve the robustness of the classifier. Considerable experimental results and studies suggest that the effectiveness of our DPC in enhancing the performance of existing SFDA baselines.
In this paper we propose Image Downscaling Assessment by Rate-Distortion (IDA-RD) a novel measure to quantitatively evaluate image downscaling algorithms. In contrast to image-based methods that measure the quality of downscaled images ours is process-based that draws ideas from rate-distortion theory to measure the distortion incurred during downscaling. Our main idea is that downscaling and super-resolution (SR) can be viewed as the encoding and decoding processes in the rate-distortion model respectively and that a downscaling algorithm that preserves more details in the resulting low-resolution (LR) images should lead to less distorted high-resolution (HR) images in SR. In other words the distortion should increase as the downscaling algorithm deteriorates. However it is non-trivial to measure this distortion as it requires the SR algorithm to be blind and stochastic. Our key insight is that such requirements can be met by recent SR algorithms based on deep generative models that can find all matching HR images for a given LR image on their learned image manifolds. Extensive experimental results show the effectiveness of our IDA-RD measure.
Backdoor attacks have been well-studied in visible light object detection (VLOD) in recent years. However VLOD can not effectively work in dark and temperature-sensitive scenarios. Instead thermal infrared object detection (TIOD) is the most accessible and practical in such environments. In this paper our team is the first to investigate the security vulnerabilities associated with TIOD in the context of backdoor attacks spanning both the digital and physical realms. We introduce two novel types of backdoor attacks on TIOD each offering unique capabilities: Object-affecting Attack and Range-affecting Attack. We conduct a comprehensive analysis of key factors influencing trigger design which include temperature size material and concealment. These factors especially temperature significantly impact the efficacy of backdoor attacks on TIOD. A thorough understanding of these factors will serve as a foundation for designing physical triggers and temperature controlling experiments. Our study includes extensive experiments conducted in both digital and physical environments. In the digital realm we evaluate our approach using benchmark datasets for TIOD achieving an Attack Success Rate (ASR) of up to 98.21%. In the physical realm we test our approach in two real-world settings: a traffic intersection and a parking lot using a thermal infrared camera.
In the digital realm we evaluate our approach using benchmark datasets for TIOD achieving an Attack Success Rate (ASR) of up to 98.21%. In the physical realm we test our approach in two real-world settings: a traffic intersection and a parking lot using a thermal infrared camera. Here we attain an ASR of up to 98.38%.
Deep Neural Networks (DNNs) are powerful tools for various computer vision tasks yet they often struggle with reliable uncertainty quantification -a critical requirement for real-world applications. Bayesian Neural Networks (BNN) are equipped for uncertainty estimation but cannot scale to large DNNs where they are highly unstable to train. To address this challenge we introduce the Adaptable Bayesian Neural Network (ABNN) a simple and scalable strategy to seamlessly transform DNNs into BNNs in a post-hoc manner with minimal computational and training overheads. ABNN preserves the main predictive properties of DNNs while enhancing their uncertainty quantification abilities through simple BNN adaptation layers (attached to normalization layers) and a few fine-tuning steps on pre-trained models. We conduct extensive experiments across multiple datasets for image classification and semantic segmentation tasks and our results demonstrate that ABNN achieves state-of-the-art performance without the computational budget typically associated with ensemble methods.
Composed image retrieval (CIR) task takes a composed query of image and text aiming to search relative images for both conditions. Conventional CIR approaches need a training dataset composed of triplets of query image query text and target image which is very expensive to collect. Several recent works have worked on the zero-shot (ZS) CIR paradigm to tackle the issue without using pre-collected triplets. However the existing ZS-CIR methods show limited backbone scalability and generalizability due to the lack of diversity of the input texts during training. We propose a novel CIR framework only using language for its training. Our LinCIR (Language-only training for CIR) can be trained only with text datasets by a novel self-supervision named self-masking projection (SMP). We project the text latent embedding to the token embedding space and construct a new text by replacing the keyword tokens of the original text. Then we let the new and original texts have the same latent embedding vector.
We project the text latent embedding to the token embedding space and construct a new text by replacing the keyword tokens of the original text. Then we let the new and original texts have the same latent embedding vector. With this simple strategy LinCIR is surprisingly efficient and highly effective; LinCIR with CLIP ViT-G backbone is trained in 48 minutes and shows the best ZS-CIR performances on four different CIR benchmarks CIRCO GeneCIS FashionIQ and CIRR even outperforming supervised method on FashionIQ. Code is available at https://github.com/navervision/lincir
The existing facial datasets while having plentiful images at near frontal views lack images with extreme head poses leading to the downgraded performance of deep learning models when dealing with profile or pitched faces. This work aims to address this gap by introducing a novel dataset named Extreme Pose Face High-Quality Dataset (EFHQ) which includes a maximum of 450k high-quality images of faces at extreme poses. To produce such a massive dataset we utilize a novel and meticulous dataset processing pipeline to curate two publicly available datasets VFHQ and CelebV-HQ which contain many high-resolution face videos captured in various settings. Our dataset can complement existing datasets on various facial-related tasks such as facial synthesis with 2D/3D-aware GAN diffusion-based text-to-image face generation and face reenactment. Specifically training with EFHQ helps models generalize well across diverse poses significantly improving performance in scenarios involving extreme views confirmed by extensive experiments. Additionally we utilize EFHQ to define a challenging cross-view face verification benchmark in which the performance of SOTA face recognition models drops 5-37% compared to frontal-to-frontal scenarios aiming to stimulate studies on face recognition under severe pose conditions in the wild.
Point Cloud Registration is a critical and challenging task in computer vision. Recent advancements have predominantly embraced a coarse-to-fine matching mechanism with the key to matching the superpoints located in patches with inter-frame consistent structures. However previous methods still face challenges with ambiguous matching because the interference information aggregated from irrelevant regions may disturb the capture of inter-frame consistency relations leading to wrong matches. To address this issue we propose Dynamic Cues-Assisted Transformer (DCATr). Firstly the interference from irrelevant regions is greatly reduced by constraining attention to certain cues i.e. regions with highly correlated structures of potential corresponding superpoints. Secondly cues-assisted attention is designed to mine the inter-frame consistency relations while more attention is assigned to pairs with high consistent confidence in feature aggregation. Finally a dynamic updating fashion is proposed to facilitate mining richer consistency information further improving aggregated features' distinctiveness and relieving matching ambiguity. Extensive evaluations on indoor and outdoor standard benchmarks demonstrate that DCATr outperforms all state-of-the-art methods.
Diffusion MRI (dMRI) non-invasively maps brain white matter yet necessitates denoising due to low signal-to-noise ratios. Patch2Self (P2S) employing self-supervised techniques and regression on a Casorati matrix effectively denoises dMRI images and has become the new de-facto standard in this field. P2S however is resource intensive both in terms of running time and memory usage as it uses all voxels (n) from all-but-one held-in volumes (d-1) to learn a linear mapping Phi : \mathbb R ^ n x(d-1)  \mapsto \mathbb R ^ n  for denoising the held-out volume. The increasing size and dimensionality of higher resolution dMRI acquisitions can make P2S infeasible for large-scale analyses. This work exploits the redundancy imposed by P2S to alleviate its performance issues and inspect regions that influence the noise disproportionately. Specifically this study makes a three-fold contribution: (1) We present Patch2Self2 (P2S2) a method that uses matrix sketching to perform self-supervised denoising.
Specifically this study makes a three-fold contribution: (1) We present Patch2Self2 (P2S2) a method that uses matrix sketching to perform self-supervised denoising. By solving a sub-problem on a smaller sub-space so called coreset we show how P2S2 can yield a significant speedup in training time while using less memory. (2) We present a theoretical analysis of P2S2 focusing on determining the optimal sketch size through rank estimation a key step in achieving a balance between denoising accuracy and computational efficiency. (3) We show how the so-called statistical leverage scores can be used to interpret the denoising of dMRI data a process that was traditionally treated as a black-box. Experimental results on both simulated and real data affirm that P2S2 maintains denoising quality while significantly enhancing speed and memory efficiency achieved by training on a reduced data subset.
Current subject-driven image generation methods encounter significant challenges in person-centric image generation. The reason is that they learn the semantic scene and person generation by fine-tuning a common pre-trained diffusion which involves an irreconcilable training imbalance. Precisely to generate realistic persons they need to sufficiently tune the pre-trained model which inevitably causes the model to forget the rich semantic scene prior and makes scene generation over-fit to the training data. Moreover even with sufficient fine-tuning these methods can still not generate high-fidelity persons since joint learning of the scene and person generation also lead to quality compromise. In this paper we propose Face-diffuser an effective collaborative generation pipeline to eliminate the above training imbalance and quality compromise. Specifically we first develop two specialized pre-trained diffusion models i.e. Text-driven Diffusion Model (TDM) and Subject-augmented Diffusion Model (SDM) for scene and person generation respectively. The sampling process is divided into three sequential stages i.e. semantic scene construction subject-scene fusion and subject enhancement. The first and last stages are performed by TDM and SDM respectively.
The sampling process is divided into three sequential stages i.e. semantic scene construction subject-scene fusion and subject enhancement. The first and last stages are performed by TDM and SDM respectively. The subject-scene fusion stage that is the collaboration achieved through a novel and highly effective mechanism Saliency-adaptive Noise Fusion (SNF). Specifically it is based on our key observation that there exists a robust link between classifier-free guidance responses and the saliency of generated images. In each time step SNF leverages the unique strengths of each model and allows for the spatial blending of predicted noises from both models automatically in a saliency-aware manner all of which can be seamlessly integrated into the DDIM sampling process. Extensive experiments confirm the impressive effectiveness and robustness of the Face-diffuser in generating high-fidelity person images depicting multiple unseen persons with varying contexts. Code is available at https://github.com/CodeGoat24/Face-diffuser.
Recent advancements in large vision-language models enabled visual object detection in open-vocabulary scenarios where object classes are defined in free-text formats during inference. In this paper we aim to probe the state-of-the-art methods for open-vocabulary object detection to determine to what extent they understand fine-grained properties of objects and their parts. To this end we introduce an evaluation protocol based on dynamic vocabulary generation to test whether models detect discern and assign the correct fine-grained description to objects in the presence of hard-negative classes. We contribute with a benchmark suite of increasing difficulty and probing different properties like color pattern and material. We further enhance our investigation by evaluating several state-of-the-art open-vocabulary object detectors using the proposed protocol and find that most existing solutions which shine in standard open-vocabulary benchmarks struggle to accurately capture and distinguish finer object details. We conclude the paper by highlighting the limitations of current methodologies and exploring promising research directions to overcome the discovered drawbacks. Data and code are available at https://lorebianchi98.github.io/FG-OVD .
Weakly-supervised action segmentation is a task of learning to partition a long video into several action segments where training videos are only accompanied by transcripts (ordered list of actions). Most of existing methods need to infer pseudo segmentation for training by serial alignment between all frames and the transcript which is time-consuming and hard to be parallelized while training. In this work we aim to escape from this inefficient alignment with massive but redundant frames and instead to directly localize a few action transitions for pseudo segmentation generation where a transition refers to the change from an action segment to its next adjacent one in the transcript. As the true transitions are submerged in noisy boundaries due to intra-segment visual variation we propose a novel Action-Transition-Aware Boundary Alignment (ATBA) framework to efficiently and effectively filter out noisy boundaries and detect transitions. In addition to boost the semantic learning in the case that noise is inevitably present in the pseudo segmentation we also introduce video-level losses to utilize the trusted video-level supervision. Extensive experiments show the effectiveness of our approach on both performance and training speed.
The ability to learn from context with novel concepts and deliver appropriate responses are essential in human conversations. Despite current Multimodal Large Language Models (MLLMs) and Large Language Models (LLMs) being trained on mega-scale datasets recognizing unseen images or understanding novel concepts in a training-free manner remains a challenge. In-Context Learning (ICL) explores training-free few-shot learning where models are encouraged to "learn to learn" from limited tasks and generalize to unseen tasks. In this work we propose link-context learning (LCL) which emphasizes "reasoning from cause and effect" to augment the learning capabilities of MLLMs. LCL goes beyond traditional ICL by explicitly strengthening the causal relationship between the support set and the query set. By providing demonstrations with causal links LCL guides the model to discern not only the analogy but also the underlying causal associations between data points which empowers MLLMs to recognize unseen images and understand novel concepts more effectively. To facilitate the evaluation of this novel approach we introduce the ISEKAI dataset comprising exclusively of unseen generated image-label pairs designed for link-context learning. Extensive experiments show that our LCL-MLLM exhibits strong link-context learning capabilities to novel concepts over vanilla MLLMs.
Large language models have achieved great success in recent years so as their variants in vision. Existing vision-language models can describe images in natural languages answer visual-related questions or perform complex reasoning about the image. However it is yet unclear how localization tasks such as word grounding or referring localization can be performed using large language models. In this work we aim to develop a vision-language model that can take locations for example a set of points or boxes as either inputs or outputs. When taking locations as inputs the model performs location-conditioned captioning which generates captions for the indicated object or region. When generating locations as outputs our model regresses pixel coordinates for each output word generated by the language model and thus performs dense word grounding. Our model is pre-trained on the Localized Narrative dataset which contains pixel-word-aligned captioning from human attention. We show our model can be applied to various location-aware vision-language tasks including referring localization location-conditioned captioning and dense object captioning archiving state-of-the-art performance on RefCOCO and Visual Genome.
Personalized text-to-image generation models enable users to create images that depict their individual possessions in diverse scenes finding applications in various domains. To achieve the personalization capability existing methods rely on finetuning a text-to-image foundation model on a user's custom dataset which can be non-trivial for general users resource-intensive and time-consuming. Despite attempts to develope finetuning-free methods their generation quality is much lower compared to their finetuning counterparts. In this paper we propose Joint-Image Diffusion (\jedi) an effective technique for learning a finetuning-free personalization model. Our key idea is to learn the joint distribution of multiple related text-image pairs that share a common subject. To facilitate learning we propose a scalable synthetic dataset generation technique. Once trained our model enables fast and easy personalization at test time by simply using reference images as input during the sampling process. Our approach does not require any expensive optimization process or additional modules and can faithfully preserve the identity represented by any number of reference images. Experimental results show that our model achieves state-of-the-art generation quality both quantitatively and qualitatively significantly outperforming both the prior finetuning-based and finetuning-free personalization baselines.
This paper proposes ConsistDreamer - a novel framework that lifts 2D diffusion models with 3D awareness and 3D consistency thus enabling high-fidelity instruction-guided scene editing. To overcome the fundamental limitation of missing 3D consistency in 2D diffusion models our key insight is to introduce three synergetic strategies that augment the input of the 2D diffusion model to become 3D-aware and to explicitly enforce 3D consistency during the training process. Specifically we design surrounding views as context-rich input for the 2D diffusion model and generate 3D-consistent structured noise instead of image-independent noise. Moreover we introduce self-supervised consistency-enforcing training within the per-scene editing procedure. Extensive evaluation shows that our ConsistDreamer achieves state-of-the-art performance for instruction-guided scene editing across various scenes and editing instructions particularly in complicated large-scale indoor scenes from ScanNet++ with significantly improved sharpness and fine-grained textures. Notably ConsistDreamer stands as the first work capable of successfully editing complex (e.g. plaid/checkered) patterns.
Extracting keypoint locations from input hand frames known as 3D hand pose estimation is a critical task in various human-computer interaction applications. Essentially the 3D hand pose estimation can be regarded as a 3D point subset generative problem conditioned on input frames. Thanks to the recent significant progress on diffusion-based generative models hand pose estimation can also benefit from the diffusion model to estimate keypoint locations with high quality. However directly deploying the existing diffusion models to solve hand pose estimation is non-trivial since they cannot achieve the complex permutation mapping and precise localization. Based on this motivation this paper proposes HandDiff a diffusion-based hand pose estimation model that iteratively denoises accurate hand pose conditioned on hand-shaped image-point clouds. In order to recover keypoint permutation and accurate location we further introduce joint-wise condition and local detail condition. Experimental results demonstrate that the proposed HandDiff significantly outperforms the existing approaches on four challenging hand pose benchmark datasets. Codes and pre-trained models are publicly available at https://github.com/cwc1260/HandDiff.