CVPR2024/CVPR2024-papers-abstract-index huggingface dataset:
This paper focuses on self-supervised monocular depth estimation in dynamic scenes trained on monocular videos. Existing methods jointly estimate pixel-wise depth and motion relying mainly on an image reconstruction loss. Dynamic regions remain a critical challenge for these methods due to the inherent ambiguity in depth and motion estimation resulting in inaccurate depth estimation. This paper proposes a self-supervised training framework exploiting pseudo depth labels for dynamic regions from training data. The key contribution of our framework is to decouple depth estimation for static and dynamic regions of images in the training data. We start with an unsupervised depth estimation approach which provides reliable depth estimates for static regions and motion cues for dynamic regions and allows us to extract moving object information at the instance level. In the next stage we use an object network to estimate the depth of those moving objects assuming rigid motions. Then we propose a new scale alignment module to address the scale ambiguity between estimated depths for static and dynamic regions. We can then use the depth labels generated to train an end-to-end depth estimation network and improve its performance. Extensive experiments on the Cityscapes and KITTI datasets show that our self-training strategy consistently outperforms existing self-/unsupervised depth estimation methods.
Recent advancements in domain generalization (DG) for face anti-spoofing (FAS) have garnered considerable attention. Traditional methods have focused on designing learning objectives and additional modules to isolate domain-specific features while retaining domain-invariant characteristics in their representations. However such approaches often lack guarantees of consistent maintenance of domain-invariant features or the complete removal of domain-specific features. Furthermore most prior works of DG for FAS do not ensure convergence to a local flat minimum which has been shown to be advantageous for DG. In this paper we introduce GAC-FAS a novel learning objective that encourages the model to converge towards an optimal flat minimum without necessitating additional learning modules. Unlike conventional sharpness-aware minimizers GAC-FAS identifies ascending points for each domain and regulates the generalization gradient updates at these points to align coherently with empirical risk minimization (ERM) gradient updates. This unique approach specifically guides the model to be robust against domain shifts. We demonstrate the efficacy of GAC-FAS through rigorous testing on challenging cross-domain FAS datasets where it establishes state-of-the-art performance.
3D reconstruction of dynamic scenes is a long-standing problem in computer graphics and increasingly difficult the less information is available. Shape-from-Template (SfT) methods aim to reconstruct a template-based geometry from RGB images or video sequences often leveraging just a single monocular camera without depth information such as regular smartphone recordings. Unfortunately existing reconstruction methods are either unphysical and noisy or slow in optimization. To solve this problem we propose a novel SfT reconstruction algorithm for cloth using a pre-trained neural surrogate model that is fast to evaluate stable and produces smooth reconstructions due to a regularizing physics simulation. Differentiable rendering of the simulated mesh enables pixel-wise comparisons between the reconstruction and a target video sequence that can be used for a gradient-based optimization procedure to extract not only shape information but also physical parameters such as stretching shearing or bending stiffness of the cloth. This allows to retain a precise stable and smooth reconstructed geometry while reducing the runtime by a factor of 400-500 compared to ?-SfT a state-of-the-art physics-based SfT approach.
Anchor-based large-scale multi-view clustering has attracted considerable attention for its effectiveness in handling massive datasets. However current methods mainly seek the consensus embedding feature for clustering by exploring global correlations between anchor graphs or projection matrices.In this paper we propose a simple yet efficient scalable multi-view tensor clustering (S2MVTC) approach where our focus is on learning correlations of embedding features within and across views. Specifically we first construct the embedding feature tensor by stacking the embedding features of different views into a tensor and rotating it. Additionally we build a novel tensor low-frequency approximation (TLFA) operator which incorporates graph similarity into embedding feature learning efficiently achieving smooth representation of embedding features within different views. Furthermore consensus constraints are applied to embedding features to ensure inter-view semantic consistency. Experimental results on six large-scale multi-view datasets demonstrate that S2MVTC significantly outperforms state-of-the-art algorithms in terms of clustering performance and CPU execution time especially when handling massive data. The code of S2MVTC is publicly available at https://github.com/longzhen520/S2MVTC.
Depression Recognition (DR) poses a considerable challenge especially in the context of the growing concerns surrounding privacy. Traditional automatic diagnosis of DR technology necessitates the use of facial images undoubtedly expose the patient identity features and poses privacy risks. In order to mitigate the potential risks associated with the inappropriate disclosure of patient facial images we design a new imaging system to erase the identity information of captured facial images while retain disease-relevant features. It is irreversible for identity information recovery while preserving essential disease-related characteristics necessary for accurate DR. More specifically we try to record a de-identified facial image (erasing the identifiable features as much as possible) by a learnable lens which is optimized in conjunction with the following DR task as well as a range of face analysis related auxiliary tasks in an end-to-end manner. These aforementioned strategies form our final Optical deep Depression Recognition network (OpticalDR).
These aforementioned strategies form our final Optical deep Depression Recognition network (OpticalDR). Experiments on CelebA AVEC 2013 and AVEC 2014 datasets demonstrate that our OpticalDR has achieved state-of-the-art privacy protection performance with an average AUC of 0.51 on popular facial recognition models and competitive results for DR with MAE/RMSE of 7.53/8.48 on AVEC 2013 and 7.89/8.82 on AVEC 2014 respectively. Code is available at https://github.com/divertingPan/OpticalDR.
We propose a novel diffusion-based image generation method called the observation-guided diffusion probabilistic model (OGDM) which effectively addresses the tradeoff between quality control and fast sampling. Our approach reestablishes the training objective by integrating the guidance of the observation process with the Markov chain in a principled way. This is achieved by introducing an additional loss term derived from the observation based on a conditional discriminator on noise level which employs a Bernoulli distribution indicating whether its input lies on the (noisy) real manifold or not. This strategy allows us to optimize the more accurate negative log-likelihood induced in the inference stage especially when the number of function evaluations is limited. The proposed training scheme is also advantageous even when incorporated only into the fine-tuning process and it is compatible with various fast inference strategies since our method yields better denoising networks using the exactly the same inference procedure without incurring extra computational cost. We demonstrate the effectiveness of our training algorithm using diverse inference techniques on strong diffusion model baselines. Our implementation is available at https://github.com/Junoh-Kang/OGDM_edm.
Two primary input modalities prevail in image retrieval: sketch and text. While text is widely used for inter-category retrieval tasks sketches have been established as the sole preferred modality for fine-grained image retrieval due to their ability to capture intricate visual details. In this paper we question the reliance on sketches alone for fine-grained image retrieval by simultaneously exploring the fine-grained representation capabilities of both sketch and text orchestrating a duet between the two. The end result enables precise retrievals previously unattainable allowing users to pose ever-finer queries and incorporate attributes like colour and contextual cues from text. For this purpose we introduce a novel compositionality framework effectively combining sketches and text using pre-trained CLIP models while eliminating the need for extensive fine-grained textual descriptions. Last but not least our system extends to novel applications in composed image retrieval domain attribute transfer and fine-grained generation providing solutions for various real-world scenarios.
Regression-based keypoint localization shows advantages of high efficiency and better robustness to quantization errors than heatmap-based methods. However existing regression-based methods discard the spatial location prior in input image with a global pooling leading to inferior accuracy and are limited to single instance localization tasks. We study the regression-based keypoint localization from a new perspective by leveraging the spatial location prior. Instead of regressing on the pooled feature the proposed Spatial-Aware Regression (SAR) maintains the spatial location map and outputs spatial coordinates and confidence score for each grid which are optimized with a unified objective. Benefited by the location prior these spatial-aware outputs can be efficiently optimized resulting in better localization performance. Moreover incorporating spatial prior makes SAR more general and can be applied into various keypoint localization tasks. We test the proposed method in 4 keypoint localization tasks including single/multi-person 2D/3D pose estimation and the whole-body pose estimation. Extensive experiments demonstrate its promising performance e.g. consistently outperforming recent regressions-based methods.
In the expansive domain of computer vision a myriad of pre-trained models are at our disposal. However most of these models are designed for natural RGB images and prove inadequate for spectral remote sensing (RS) images. Spectral RS images have two main traits: (1) multiple bands capturing diverse feature information (2) spatial alignment and consistent spectral sequencing within the spatial-spectral dimension. In this paper we introduce Spatial-SpectralMAE (S2MAE) a specialized pre-trained architecture for spectral RS imagery. S2MAE employs a 3D transformer for masked autoencoder modeling integrating learnable spectral-spatial embeddings with a 90% masking ratio. The model efficiently captures local spectral consistency and spatial invariance using compact cube tokens demonstrating versatility to diverse input characteristics. This adaptability facilitates progressive pretraining on extensive spectral datasets. The effectiveness of S2MAE is validated through continuous pretraining on two sizable datasets totaling over a million training images. The pre-trained model is subsequently applied to three distinct downstream tasks with in-depth ablation studies conducted to emphasize its efficacy.
The portrait matting task aims to extract an alpha matte with complete semantics and finely detailed contours. In comparison to CNN-based approaches transformers with self-attention module have a better capacity to capture long-range dependencies and low-frequency semantic information of a portrait. However recent research shows that the self-attention mechanism struggles with modeling high-frequency contour information and capturing fine contour details which can lead to bias while predicting the portrait's contours. To deal with this issue we propose EFormer to enhance the model's attention towards both the low-frequency semantic and high-frequency contour features. For the high-frequency contours our research demonstrates that cross-attention module between different resolutions can guide our model to allocate attention appropriately to these contour regions. Supported by this we can successfully extract the high-frequency detail information around the portrait's contours which were previously ignored by self-attention. Based on the cross-attention module we further build a semantic and contour detector (SCD) to accurately capture both the low-frequency semantic and high-frequency contour features. And we design a contour-edge extraction branch and semantic extraction branch to extract refined high-frequency contour features and complete low-frequency semantic information respectively. Finally we fuse the two kinds of features and leverage the segmentation head to generate a predicted portrait matte.
And we design a contour-edge extraction branch and semantic extraction branch to extract refined high-frequency contour features and complete low-frequency semantic information respectively. Finally we fuse the two kinds of features and leverage the segmentation head to generate a predicted portrait matte. Experiments on VideoMatte240K (JPEG SD Format) and Adobe Image Matting (AIM) datasets demonstrate that EFormer outperforms previous portrait matte methods.
We present MultiPly a novel framework to reconstruct multiple people in 3D from monocular in-the-wild videos. Reconstructing multiple individuals moving and interacting naturally from monocular in-the-wild videos poses a challenging task. Addressing it necessitates precise pixel-level disentanglement of individuals without any prior knowledge about the subjects. Moreover it requires recovering intricate and complete 3D human shapes from short video sequences intensifying the level of difficulty. To tackle these challenges we first define a layered neural representation for the entire scene composited by individual human and background models. We learn the layered neural representation from videos via our layer-wise differentiable volume rendering. This learning process is further enhanced by our hybrid instance segmentation approach which combines the self-supervised 3D segmentation and the promptable 2D segmentation module yielding reliable instance segmentation supervision even under close human interaction. A confidence-guided optimization formulation is introduced to optimize the human poses and shape/appearance alternately. We incorporate effective objectives to refine human poses via photometric information and impose physically plausible constraints on human dynamics leading to temporally consistent 3D reconstructions with high fidelity. The evaluation of our method shows the superiority over prior art on publicly available datasets and in-the-wild videos.
Understanding 3D object structure from image collections of general object categories remains a long-standing challenge in computer vision. Due to the high relevance of image keypoints (e.g. for graph matching controlling generative models scene understanding etc.) in this work we specifically focus on inferring 3D structure in terms of sparse keypoints. Existing 3D keypoint inference approaches rely on strong priors such as spatio-temporal consistency multi-view images of the same object 3D shape priors (e.g. templates skeleton) or supervisory signals e.g. in the form of 2D keypoint annotations. In contrast we propose the first unsupervised 3D keypoint inference approach that can be trained for general object categories solely from an inhomogeneous image collection (containing different instances of objects from the same category). Our experiments show that our method not only improves upon unsupervised 2D keypoint inference but more importantly it also produces reasonable 3D structure for various object categories both qualitatively and quantitatively.
While deep learning has led to huge progress in complex image classification tasks like ImageNet unexpected failure modes e.g. via spurious features call into question how reliably these classifiers work in the wild. Furthermore for safety-critical tasks the black-box nature of their decisions is problematic and explanations or at least methods which make decisions plausible are needed urgently. In this paper we address these problems by generating images that optimize a classifier-derived objective using a framework for guided image generation. We analyze the decisions of image classifiers by visual counterfactual explanations (VCEs) detection of systematic mistakes by analyzing images where classifiers maximally disagree and visualization of neurons and spurious features. In this way we validate existing observations e.g. the shape bias of adversarially robust models as well as novel failure modes e.g. systematic errors of zero-shot CLIP classifiers. Moreover our VCEs outperform previous work while being more versatile.
Recently lightweight Vision Transformers (ViTs) demonstrate superior performance and lower latency compared with lightweight Convolutional Neural Networks (CNNs) on resource-constrained mobile devices. Researchers have discovered many structural connections between lightweight ViTs and lightweight CNNs. However the notable architectural disparities in the block structure macro and micro designs between them have not been adequately examined. In this study we revisit the efficient design of lightweight CNNs from ViT perspective and emphasize their promising prospect for mobile devices. Specifically we incrementally enhance the mobile-friendliness of a standard lightweight CNN i.e. MobileNetV3 by integrating the efficient architectural designs of lightweight ViTs. This ends up with a new family of pure lightweight CNNs namely RepViT. Extensive experiments show that RepViT outperforms existing state-of-the-art lightweight ViTs and exhibits favorable latency in various vision tasks. Notably on ImageNet RepViT achieves over 80% top-1 accuracy with 1.0 ms latency on an iPhone 12 which is the first time for a lightweight model to the best of our knowledge. Besides when RepViT meets SAM our RepViT-SAM can achieve nearly 10xfaster inference than the advanced MobileSAM.
Besides when RepViT meets SAM our RepViT-SAM can achieve nearly 10xfaster inference than the advanced MobileSAM. Codes and models are available at https://github.com/THU-MIG/RepViT.
We present Monocular Neural Parametric Head Models (MonoNPHM) for dynamic 3D head reconstructions from monocular RGB videos. To this end we propose a latent appearance space that parameterizes a texture field on top of a neural parametric model. We constrain predicted color values to be correlated with the underlying geometry such that gradients from RGB effectively influence latent geometry codes during inverse rendering. To increase the representational capacity of our expression space we augment our backward deformation field with hyper-dimensions thus improving color and geometry representation in topologically challenging expressions. Using MonoNPHM as a learned prior we approach the task of 3D head reconstruction using signed distance field based volumetric rendering. By numerically inverting our backward deformation field we incorporated a landmark loss using facial anchor points that are closely tied to our canonical geometry representation. We incorporate a facial landmark loss by numerically inverting our backward deformation field tied with our canonical geometry to observed 2D facial landmarks in posed space. To evaluate the task of dynamic face reconstruction from monocular RGB videos we record 20 challenging Kinect sequences under casual conditions. MonoNPHM outperforms all baselines with a significant margin and makes an important step towards easily accessible neural parametric face models through RGB tracking.
Point-level weakly-supervised temporal action localization (P-TAL) aims to localize action instances in untrimmed videos through the use of single-point annotations in each instance. Existing methods predict the class activation sequences without any boundary information and the unreliable sequences result in a significant misalignment between the quality of proposals and their corresponding confidence. In this paper we surprisingly observe the most salient frame tend to appear in the central region of the each instance and is easily annotated by humans. Guided by the temporal saliency information we present a novel proposal-level plug-in framework to relearn the aligned confidence of proposals generated by the base locators. The proposed approach consists of Center Score Learning (CSL) and Alignment-based Boundary Adaptation (ABA). In CSL we design a novel center label generated by the point annotations for predicting aligned center scores. During inference we first fuse the center scores with the predicted action probabilities to obtain the aligned confidence. ABA utilizes the both aligned confidence and IoU information to enhance localization completeness. Extensive experiments demonstrate the generalization and effectiveness of the proposed framework showcasing state-of-the-art or competitive performances across three benchmarks. Our code is available at https://github.com/zyxia1009/CVPR2024-TSPNet.
Given a single image of a 3D object this paper proposes a novel method (named ConsistNet) that can generate multiple images of the same object as if they are captured from different viewpoints while the 3D (multi-view) consistencies among those multiple generated images are effectively exploited. Central to our method is a lightweight multi-view consistency block that enables information exchange across multiple single-view diffusion processes based on the underlying multi-view geometry principles. ConsistNet is an extension to the standard latent diffusion model and it consists of two submodules: (a) a view aggregation module that unprojects multi-view features into global 3D volumes and infers consistency and (b) a ray aggregation module that samples and aggregates 3D consistent features back to each view to enforce consistency. Our approach departs from previous methods in multi-view image generation in that it can be easily dropped in pre-trained LDMs without requiring explicit pixel correspondences or depth prediction. Experiments show that our method effectively learns 3D consistency over a frozen Zero123-XL backbone and can generate 16 surrounding views of the object within 11 seconds on a single A100 GPU.
We present GenN2N a unified NeRF-to-NeRF translation framework for various NeRF translation tasks such as text-driven NeRF editing colorization super-resolution inpainting etc. Unlike previous methods designed for individual translation tasks with task-specific schemes GenN2N achieves all these NeRF editing tasks by employing a plug-and-play image-to-image translator to perform editing in the 2D domain and lifting 2D edits into the 3D NeRF space. Since the 3D consistency of 2D edits may not be assured we propose to model the distribution of the underlying 3D edits through a generative model that can cover all possible edited NeRFs. To model the distribution of 3D edited NeRFs from 2D edited images we carefully design a VAE-GAN that encodes images while decoding NeRFs. The latent space is trained to align with a Gaussian distribution and the NeRFs are supervised through an adversarial loss on its renderings. To ensure the latent code does not depend on 2D viewpoints but truly reflects the 3D edits we also regularize the latent code through a contrastive learning scheme.
To ensure the latent code does not depend on 2D viewpoints but truly reflects the 3D edits we also regularize the latent code through a contrastive learning scheme. Extensive experiments on various editing tasks show GenN2N as a universal framework performs as well or better than task-specific specialists while possessing flexible generative power. More results on our project page: https://xiangyueliu.github.io/GenN2N/.