CVPR2024/CVPR2024-papers-abstract-index huggingface dataset:
Instance segmentation of point clouds is a crucial task in 3D field with numerous applications that involve localizing and segmenting objects in a scene. However achieving satisfactory results requires a large number of manual annotations which is time-consuming and expensive. To alleviate dependency on annotations we propose a novel framework FreePoint for underexplored unsupervised class-agnostic instance segmentation on point clouds. In detail we represent the point features by combining coordinates colors and self-supervised deep features. Based on the point features we perform a bottom-up multicut algorithm to segment point clouds into coarse instance masks as pseudo labels which are used to train a point cloud instance segmentation model. We propose an id-as-feature strategy at this stage to alleviate the randomness of the multicut algorithm and improve the pseudo labels' quality. During training we propose a weakly-supervised two-step training strategy and corresponding losses to overcome the inaccuracy of coarse masks. FreePoint has achieved breakthroughs in unsupervised class-agnostic instance segmentation on point clouds and outperformed previous traditional methods by over 18.2% and a competitive concurrent work UnScene3D by 5.5% in AP.
FreePoint has achieved breakthroughs in unsupervised class-agnostic instance segmentation on point clouds and outperformed previous traditional methods by over 18.2% and a competitive concurrent work UnScene3D by 5.5% in AP. Additionally when used as a pretext task and fine-tuned on S3DIS FreePoint performs significantly better than existing self-supervised pre-training methods with limited annotations and surpasses CSC by 6.0% in AP with 10% annotation masks. Code will be released at https://github.com/zzk273/FreePoint.
We propose the Pose Adapted Shape Learning (PASL) for large-pose face reenactment. The PASL framework consists of three modules namely the Pose-Adapted face Encoder (PAE) the Cycle-consistent Shape Generator (CSG) and the Attention-Embedded Generator (AEG). Different from previous approaches that use a single face encoder for identity preservation we propose multiple Pose-Adapted face Encodes (PAEs) to better preserve facial identity across large poses. Given a source face and a reference face the CSG generates a recomposed shape that fuses the source identity and reference action in the shape space and meets the cycle consistency requirement. Taking the shape code and the source as inputs the AEG learns the attention within the shape code and between the shape code and source style to enhance the generation of the desired target face. As existing benchmark datasets are inappropriate for evaluating large-pose face reenactment we propose a scheme to compose large-pose face pairs and introduce the MPIE-LP (Large Pose) and VoxCeleb2-LP datasets as the new large-pose benchmarks.
As existing benchmark datasets are inappropriate for evaluating large-pose face reenactment we propose a scheme to compose large-pose face pairs and introduce the MPIE-LP (Large Pose) and VoxCeleb2-LP datasets as the new large-pose benchmarks. We compared our approach with state-of-the-art methods on MPIE-LP and VoxCeleb2-LP for large-pose performance and on VoxCeleb1 for the common scope of pose variation.
Estimating the pose of objects from images is a crucial task of 3D scene understanding and recent approaches have shown promising results on very large benchmarks. However these methods experience a significant performance drop when dealing with unseen objects. We believe that it results from the limited generalizability of image features. To address this problem we have an in-depth analysis on the features of diffusion models e.g. Stable Diffusion which hold substantial potential for modeling unseen objects. Based on this analysis we then innovatively introduce these diffusion features for object pose estimation. To achieve this we propose three distinct architectures that can effectively capture and aggregate diffusion features of different granularity greatly improving the generalizability of object pose estimation. Our approach outperforms the state-of-the-art methods by a considerable margin on three popular benchmark datasets LM O-LM and T-LESS. In particular our method achieves higher accuracy than the previous best arts on unseen objects: 98.2% vs. 93.5% on Unseen LM 85.9% vs. 76.3% on Unseen O-LM showing the strong generalizability of our method. Our code is released at https://github.com/Tianfu18/diff-feats-pose.
For the essential operation namely inner product (IP) as widely adopted in classic computing e.g. matrix multiplication its quantum counterpart: quantum inner product (QIP) has also been recently theoretically explored with a verifiable lower complexity on quantum computers. However it remains unclear for the embodiment of the quantum circuits (QC) for QIP let alone a (thorough) evaluation of the QIP circuits especially in a practical context in the NISQ era by applying QIP to ML via hybrid quantum-classic pipelines. In this paper we carefully design the QIP circuits from scratch whose complexity is in accordance with the theoretical complexity. To make the simulation tractable on classic computers especially when it is integrated in the gradient-based hybrid ML pipelines we further devise a highly-efficient simulation scheme by directly simulates the output state. Experiments show that the scheme accelerates the simulation for more than 68k times compared with the previous circuit simulator. This allows our empirical evaluation on typical machine learning tasks ranging from supervised and self-supervised learning via neural nets to K-Means clustering. The results show that the calculation error brought by typical quantum mechanisms would incur in general little influence on the final numerical results given sufficient qubits. However certain tasks e.g.
The results show that the calculation error brought by typical quantum mechanisms would incur in general little influence on the final numerical results given sufficient qubits. However certain tasks e.g. ranking in K-Means could be more sensitive to quantum noise.
Dominant dual-encoder models enable efficient image-text retrieval but suffer from limited accuracy while the cross-encoder models offer higher accuracy at the expense of efficiency. Distilling cross-modality matching knowledge from cross-encoder to dual-encoder provides a natural approach to harness their strengths. Thus we investigate the following valuable question: how to make cross-encoder a good teacher for dual-encoder? Our findings are threefold: (1) Cross-modal similarity score distribution of cross-encoder is more concentrated while the result of dual-encoder is nearly normal making vanilla logit distillation less effective. However ranking distillation remains practical as it is not affected by the score distribution. (2) Only the relative order between hard negatives conveys valid knowledge while the order information between easy negatives has little significance. (3) Maintaining the coordination between distillation loss and dual-encoder training loss is beneficial for knowledge transfer. Based on these findings we propose a novel Contrastive Partial Ranking Distillation (CPRD) method which implements the objective of mimicking relative order between hard negative samples with contrastive learning. This approach coordinates with the training of the dual-encoder effectively transferring valid knowledge from the cross-encoder to the dual-encoder.
This approach coordinates with the training of the dual-encoder effectively transferring valid knowledge from the cross-encoder to the dual-encoder. Extensive experiments on image-text retrieval and ranking tasks show that our method surpasses other distillation methods and significantly improves the accuracy of dual-encoder.
We describe a method for recovering the irradiance underlying a collection of images corrupted by atmospheric turbulence. Since supervised data is often technically impossible to obtain assumptions and biases have to be imposed to solve this inverse problem and we choose to model them explicitly. Rather than initializing a latent irradiance ("template") by heuristics to estimate deformation we select one of the images as a reference and model the deformation in this image by the aggregation of the optical flow from it to other images exploiting a prior imposed by Central Limit Theorem. Then with a novel flow inversion module the model registers each image TO the template but WITHOUT the template avoiding artifacts related to poor template initialization. To illustrate the robustness of the method we simply (i) select the first frame as the reference and (ii) use the simplest optical flow to estimate the warpings yet the improvement in registration is decisive in the final reconstruction as we achieve state-of-the-art performance despite its simplicity. The method establishes a strong baseline that can be further improved by integrating it seamlessly into more sophisticated pipelines or with domain-specific methods if so desired.
Many instruments performing optical and non-optical imaging and sensing such as Optical Coherence Tomography (OCT) Magnetic Resonance Imaging or Fourier-transform spectrometry produce digital signals containing modulations sine-like components which only after Fourier transformation give information about the structure or characteristics of the investigated object. Due to the fundamental physics-related limitations of such methods the distribution of these signal components is often nonlinear and when not properly compensated leads to the resolution precision or quality drop in the final image. Here we propose an innovative approach that has the potential to allow cleaning of the signal from the nonlinearities but most of all it now allows to switch the given order off leaving all others intact. The latter provides a tool for more in-depth analysis of the nonlinearity-inducing properties of the investigated object which can lead to applications in early disease detection or more sensitive sensing of chemical compounds. We consider OCT signals and nonlinearities up to the third order. In our approach we propose two neural networks: one to remove solely the second-order nonlinearity and the other for removing solely the third-order nonlinearity. The input of the networks is a novel two-dimensional data structure with all the information needed for the network to infer a nonlinearity-free signal.
In our approach we propose two neural networks: one to remove solely the second-order nonlinearity and the other for removing solely the third-order nonlinearity. The input of the networks is a novel two-dimensional data structure with all the information needed for the network to infer a nonlinearity-free signal. We describe the developed networks and present the results for second-order and third-order nonlinearity removal in OCT data representing the images of various objects: a mirror glass and fruits.
The removal of atmospheric turbulence is crucial for long-distance imaging. Leveraging the stochastic nature of atmospheric turbulence numerous algorithms have been developed that employ multi-frame input to mitigate the turbulence. However when limited to a single frame existing algorithms face substantial performance drops particularly in diverse real-world scenes. In this paper we propose a robust solution to turbulence removal from an RGB image under the guidance of an additional narrow-band image broadening the applicability of turbulence mitigation techniques in real-world imaging scenarios. Our approach exhibits a substantial suppression in the magnitude of turbulence artifacts by using only a pair of images thereby enhancing the clarity and fidelity of the captured scene.
The robust generalization of models to rare in-distribution (ID) samples drawn from the long tail of the training distribution and to out-of-training-distribution (OOD) samples is one of the major challenges of current deep learning methods. For image classification this manifests in the existence of adversarial attacks the performance drops on distorted images and a lack of generalization to concepts such as sketches. The current understanding of generalization in neural networks is very limited but some biases that differentiate models from human vision have been identified and might be causing these limitations. Consequently several attempts with varying success have been made to reduce these biases during training to improve generalization. We take a step back and sanity-check these attempts. Fixing the architecture to the well-established ResNet-50 we perform a large-scale study on 48 ImageNet models obtained via different training methods to understand how and if these biases - including shape bias spectral biases and critical bands - interact with generalization. Our extensive study results reveal that contrary to previous findings these biases are insufficient to accurately predict the generalization of a model holistically. We provide access to all checkpoints and evaluation code at https://github.com/paulgavrikov/biases_vs_generalization/
Faithfully modeling the space of articulations is a crucial task that allows recovery and generation of realistic poses and remains a notorious challenge. To this end we introduce Neural Riemannian Distance Fields (NRDFs) data-driven priors modeling the space of plausible articulations represented as the zero-level-set of a neural field in a high-dimensional product-quaternion space. To train NRDFs only on positive examples we introduce a new sampling algorithm ensuring that the geodesic distances follow a desired distribution yielding a principled distance field learning paradigm. We then devise a projection algorithm to map any random pose onto the level-set by an adaptive-step Riemannian optimizer adhering to the product manifold of joint rotations at all times. NRDFs can compute the Riemannian gradient via backpropagation and by mathematical analogy are related to Riemannian flow matching a recent generative model. We conduct a comprehensive evaluation of NRDF against other pose priors in various downstream tasks i.e. pose generation image-based pose estimation and solving inverse kinematics highlighting NRDF's superior performance. Besides humans NRDF's versatility extends to hand and animal poses as it can effectively represent any articulation.
The simulated annealing algorithm aims to improve model convergence through multiple restarts of training. However existing annealing algorithms overlook the correlation between different cycles neglecting the potential for incremental learning. We contend that a fixed network structure prevents the model from recognizing distinct features at different training stages. To this end we propose RepAn redesigning the irreversible re-parameterization (Rep) method and integrating it with annealing to enhance training. Specifically the network goes through Rep expansion restoration and backpropagation operations during training and iterating through these processes in each annealing round. Such a method exhibits good generalization and is easy to apply and we provide theoretical explanations for its effectiveness. Experiments demonstrate that our method improves baseline performance by 6.38% on the CIFAR-100 dataset and 2.80% on ImageNet achieving state-of-the-art performance in the Rep field. The code is available at https://github.com/xfey/RepAn.
The astonishing development of single-photon cameras has created an unprecedented opportunity for scientific and industrial imaging. However the high data throughput generated by these 1-bit sensors creates a significant bottleneck for low-power applications. In this paper we explore the possibility of generating a color image from a single binary frame of a single-photon camera. We evidently find this problem being particularly difficult to standard colorization approaches due to the substantial degree of exposure variation. The core innovation of our paper is an exposure synthesis model framed under a neural ordinary differential equation (Neural ODE) that allows us to generate a continuum of exposures from a single observation. This innovation ensures consistent exposure in binary images that colorizers take on resulting in notably enhanced colorization. We demonstrate applications of the method in single-image and burst colorization and show superior generative performance over baselines. Project website can be found at https://vishal-s-p.github.io/projects/2023/generative_quanta_color.html
The quality of the data and annotation upper-bounds the quality of a downstream model. While there exist large text corpora and image-text pairs high-quality video-text data is much harder to collect. First of all manual labeling is more time-consuming as it requires an annotator to watch an entire video. Second videos have a temporal dimension consist of a number of scenes stacked together and show multiple actions. Accordingly to establish a video dataset with high-quality captions we propose an automatic approach leveraging multimodal inputs such as textual video description subtitles and individual video frames. Specifically we curate 3.8M high-resolution videos from the publicly available HD-VILA-100M dataset. We then split them into semantically consistent video clips and apply multiple cross-modality teacher models to obtain captions for each video. Next we finetune a retrieval model on a small subset where the best caption of each video is manually selected and then employ the model in the whole dataset to select the best caption as the annotation. In this way we get 70M videos paired with high-quality text captions. We dub the dataset as Panda-70M.
In this way we get 70M videos paired with high-quality text captions. We dub the dataset as Panda-70M. We show the value of the proposed dataset on three downstream tasks: video captioning video and text retrieval and text-driven video generation. The models trained on the proposed data score substantially better on the majority of metrics across all the tasks.
Nowadays the deployment of deep learning-based applications is an essential task owing to the increasing demands on intelligent services. In this paper we investigate latency attacks on deep learning applications. Unlike common adversarial attacks for misclassification the goal of latency attacks is to increase the inference time which may stop applications from responding to the requests within a reasonable time. This kind of attack is ubiquitous for various applications and we use object detection to demonstrate how such kind of attacks work. We also design a framework named Overload to generate latency attacks at scale. Our method is based on a newly formulated optimization problem and a novel technique called spatial attention. This attack serves to escalate the required computing costs during the inference time consequently leading to an extended inference time for object detection. It presents a significant threat especially to systems with limited computing resources. We conducted experiments using YOLOv5 models on Nvidia NX. Compared to existing methods our method is simpler and more effective. The experimental results show that with latency attacks the inference time of a single image can be increased ten times longer in reference to the normal setting. Moreover our findings pose a potential new threat to all object detection tasks requiring non-maximum suppression (NMS) as our attack is NMS-agnostic.
3D generation has raised great attention in recent years. With the success of text-to-image diffusion models the 2D-lifting technique becomes a promising route to controllable 3D generation. However these methods tend to present inconsistent geometry which is also known as the Janus problem. We observe that the problem is caused mainly by two aspects i.e. viewpoint bias in 2D diffusion models and overfitting of the optimization objective. To address it we propose a two-stage 2D-lifting framework namely DreamControl which optimizes coarse NeRF scenes as 3D self-prior and then generates fine-grained objects with control-based score distillation. Specifically adaptive viewpoint sampling and boundary integrity metric are proposed to ensure the consistency of generated priors. The priors are then regarded as input conditions to maintain reasonable geometries in which conditional LoRA and weighted score are further proposed to optimize detailed textures. DreamControl can generate high-quality 3D content in terms of both geometry consistency and texture fidelity. Moreover our control-based optimization guidance is applicable to more downstream tasks including user-guided generation and 3D animation.
Recently infrared small target detection (IRSTD) has been dominated by deep-learning-based methods. However these methods mainly focus on the design of complex model structures to extract discriminative features leaving the loss functions for IRSTD under-explored. For example the widely used Intersection over Union (IoU) and Dice losses lack sensitivity to the scales and locations of targets limiting the detection performance of detectors. In this paper we focus on boosting detection performance with a more effective loss but a simpler model structure. Specifically we first propose a novel Scale and Location Sensitive (SLS) loss to handle the limitations of existing losses: 1) for scale sensitivity we compute a weight for the IoU loss based on target scales to help the detector distinguish targets with different scales: 2) for location sensitivity we introduce a penalty term based on the center points of targets to help the detector localize targets more precisely. Then we design a simple Multi-Scale Head to the plain U-Net (MSHNet). By applying SLS loss to each scale of the predictions our MSHNet outperforms existing state-of-the-art methods by a large margin.
Then we design a simple Multi-Scale Head to the plain U-Net (MSHNet). By applying SLS loss to each scale of the predictions our MSHNet outperforms existing state-of-the-art methods by a large margin. In addition the detection performance of existing detectors can be further improved when trained with our SLS loss demonstrating the effectiveness and generalization of our SLS loss. The code is available at https://github.com/ying-fu/MSHNet.
Spurious correlations can cause strong biases in deep neural networks impairing generalization ability. While most existing debiasing methods require full supervision on either spurious attributes or target labels training a debiased model from a limited amount of both annotations is still an open question. To address this issue we investigate an interesting phenomenon using the spectral analysis of latent representations: spuriously correlated attributes make neural networks inductively biased towards encoding lower effective rank representations. We also show that a rank regularization can amplify this bias in a way that encourages highly correlated features. Leveraging these findings we propose a self-supervised debiasing framework potentially compatible with unlabeled samples. Specifically we first pretrain a biased encoder in a self-supervised manner with the rank regularization serving as a semantic bottleneck to enforce the encoder to learn the spuriously correlated attributes. This biased encoder is then used to discover and upweight bias-conflicting samples in a downstream task serving as a boosting to effectively debias the main model. Remarkably the proposed debiasing framework significantly improves the generalization performance of self-supervised learning baselines and in some cases even outperforms state-of-the-art supervised debiasing approaches.