Modern Review Helpfulness Prediction systems are dependent upon multiple modalities, typically texts and images. Unfortunately, those contemporary approaches pay scarce attention to polish representations of cross-modal relations and tend to suffer from inferior optimization. This might cause harm to model's predictions in numerous cases. To overcome the aforementioned issues, we propose Multimodal Contrastive Learning for Multimodal Review Helpfulness Prediction (MRHP) problem, concentrating on mutual information between input modalities to explicitly elaborate cross-modal relations. In addition, we introduce Adaptive Weighting scheme for our contrastive learning approach in order to increase flexibility in optimization. Lastly, we propose Multimodal Interaction module to address the unalignment nature of multimodal data, thereby assisting the model in producing more reasonable multimodal representations. Experimental results show that our method outperforms prior baselines and achieves state-of-the-art results on two publicly available benchmark datasets for MRHP problem.

随着图像文本对的大量数据以及视觉和语言（V＆L）任务的多样性，学者在该研究领域引入了大量的深度学习模型。此外，近年来，转移学习还显示出在计算机愿景中的巨大成功，例如图像分类，对象检测等以及在自然语言处理中以进行问答，机器翻译等的自然语言处理。继承转移学习的精神， V＆L的研究工作已经在大规模数据集上设计了多种预训练技术，以增强下游任务的性能。本文的目的是提供当代V＆L预审前模型的全面修订。特别是，我们对预处理的方法进行了分类和描述，以及最先进的视觉和语言预训练模型的摘要。此外，还提供了培训数据集和下游任务的列表，以进一步提高V＆L预处理的观点。最后，我们决定采取进一步的一步，讨论众多未来研究的方向。

深度估计对于各种重要的现实世界应用至关重要，例如自动驾驶。但是，在高速场景中，它遭受了严重的性能退化，因为传统相机只能捕获模糊的图像。为了解决这个问题，Spike摄像头旨在以高框架速率捕获像素的亮度强度。但是，使用传统的单眼或立体声深度估计算法，使用尖峰摄像机的深度估计仍然非常具有挑战性，这些算法基于光度一致性。在本文中，我们提出了一种新型的不确定性引导深度融合（UGDF）框架，以融合Spike摄像机的单眼和立体声深度估计网络的预测。我们的框架是由于立体声尖峰深度估计在近距离取得更好的结果，而单眼尖峰深度估计获得了更好的结果。因此，我们引入了具有联合培训策略的双任务深度估计结构，并估算了分布式不确定性以融合单眼和立体声结果。为了证明尖峰深度估计比传统的摄像头深度估计的优势，我们为一个名为CitySpike20k的尖峰深度数据集，其中包含20k配对的样品，以进行尖峰深度估计。 UGDF在CitySpike20k上取得了最新的结果，超过了所有单眼或立体声尖峰深度估计基线。我们进行了广泛的实验，以评估我们方法对CitySpike20k的有效性和概括。据我们所知，我们的框架是第一个用于尖峰摄像头深度估算的双任务融合框架。代码和数据集将发布。

当前的点云检测方法由于其有限的概括能力而难以检测现实世界中的开放式摄制对象。此外，收集和注释带有许多类别的对象的点云检测数据集和完全注释点云检测数据集非常艰辛，而且昂贵 - 云检测。据我们所知，我们是第一个研究开放式3D点云检测问题的问题。我们没有寻求带有完整标签的点云数据集，而是求助于ImagEnet1k，以扩大点云检测器的词汇。我们建议使用图像级的类监督OV-3DETIC，这是一种开放式摄影3D检测器。具体而言，我们利用了两种模式，即用于识别的图像模态和定位的点云模态，以生成看不见类的伪标签。然后，我们提出了一种新颖的跨模式对比度学习方法，将知识从图像模态转移到训练过程中的点云模态。 OV-3Detic在不损害推理期间的延迟的情况下使点云检测器能够实现开放式摄影检测。广泛的实验表明，所提出的OV-3DETIC分别在Sun-RGBD数据集和Scannet数据集上分别在SUN-RGBD数据集和扫描仪数据集上分别实现了至少10.77％的地图改进（绝对值）和9.56％的地图改进（绝对值）。此外，我们进行了足够的实验，以阐明为什么提出的OV-3Detic作品。

最近，检测变压器（DETR）是一种端到端对象检测管道，已达到有希望的性能。但是，它需要大规模标记的数据，并遭受域移位，尤其是当目标域中没有标记的数据时。为了解决这个问题，我们根据平均教师框架MTTRANS提出了一个端到端的跨域检测变压器，该变压器可以通过伪标签充分利用对象检测训练中未标记的目标域数据和在域之间的传输知识中的传输知识。我们进一步提出了综合的多级特征对齐方式，以改善由平均教师框架生成的伪标签，利用跨尺度的自我注意事项机制在可变形的DETR中。图像和对象特征在本地，全局和实例级别与基于域查询的特征对齐（DQFA），基于BI级的基于图形的原型对齐（BGPA）和Wine-Wise图像特征对齐（TIFA）对齐。另一方面，未标记的目标域数据伪标记，可用于平均教师框架的对象检测训练，可以导致更好的特征提取和对齐。因此，可以根据变压器的架构对迭代和相互优化的平均教师框架和全面的多层次特征对齐。广泛的实验表明，我们提出的方法在三个领域适应方案中实现了最先进的性能，尤其是SIM10K到CityScapes方案的结果，从52.6地图提高到57.9地图。代码将发布。

A recent study has shown a phenomenon called neural collapse in that the within-class means of features and the classifier weight vectors converge to the vertices of a simplex equiangular tight frame at the terminal phase of training for classification. In this paper, we explore the corresponding structures of the last-layer feature centers and classifiers in semantic segmentation. Based on our empirical and theoretical analysis, we point out that semantic segmentation naturally brings contextual correlation and imbalanced distribution among classes, which breaks the equiangular and maximally separated structure of neural collapse for both feature centers and classifiers. However, such a symmetric structure is beneficial to discrimination for the minor classes. To preserve these advantages, we introduce a regularizer on feature centers to encourage the network to learn features closer to the appealing structure in imbalanced semantic segmentation. Experimental results show that our method can bring significant improvements on both 2D and 3D semantic segmentation benchmarks. Moreover, our method ranks 1st and sets a new record (+6.8% mIoU) on the ScanNet200 test leaderboard. Code will be available at https://github.com/dvlab-research/Imbalanced-Learning.

Weakly-supervised object localization aims to indicate the category as well as the scope of an object in an image given only the image-level labels. Most of the existing works are based on Class Activation Mapping (CAM) and endeavor to enlarge the discriminative area inside the activation map to perceive the whole object, yet ignore the co-occurrence confounder of the object and context (e.g., fish and water), which makes the model inspection hard to distinguish object boundaries. Besides, the use of CAM also brings a dilemma problem that the classification and localization always suffer from a performance gap and can not reach their highest accuracy simultaneously. In this paper, we propose a casual knowledge distillation method, dubbed KD-CI-CAM, to address these two under-explored issues in one go. More specifically, we tackle the co-occurrence context confounder problem via causal intervention (CI), which explores the causalities among image features, contexts, and categories to eliminate the biased object-context entanglement in the class activation maps. Based on the de-biased object feature, we additionally propose a multi-teacher causal distillation framework to balance the absorption of classification knowledge and localization knowledge during model training. Extensive experiments on several benchmarks demonstrate the effectiveness of KD-CI-CAM in learning clear object boundaries from confounding contexts and addressing the dilemma problem between classification and localization performance.

Witnessing the impressive achievements of pre-training techniques on large-scale data in the field of computer vision and natural language processing, we wonder whether this idea could be adapted in a grab-and-go spirit, and mitigate the sample inefficiency problem for visuomotor driving. Given the highly dynamic and variant nature of the input, the visuomotor driving task inherently lacks view and translation invariance, and the visual input contains massive irrelevant information for decision making, resulting in predominant pre-training approaches from general vision less suitable for the autonomous driving task. To this end, we propose PPGeo (Policy Pre-training via Geometric modeling), an intuitive and straightforward fully self-supervised framework curated for the policy pretraining in visuomotor driving. We aim at learning policy representations as a powerful abstraction by modeling 3D geometric scenes on large-scale unlabeled and uncalibrated YouTube driving videos. The proposed PPGeo is performed in two stages to support effective self-supervised training. In the first stage, the geometric modeling framework generates pose and depth predictions simultaneously, with two consecutive frames as input. In the second stage, the visual encoder learns driving policy representation by predicting the future ego-motion and optimizing with the photometric error based on current visual observation only. As such, the pre-trained visual encoder is equipped with rich driving policy related representations and thereby competent for multiple visuomotor driving tasks. Extensive experiments covering a wide span of challenging scenarios have demonstrated the superiority of our proposed approach, where improvements range from 2% to even over 100% with very limited data. Code and models will be available at https://github.com/OpenDriveLab/PPGeo.

In this work, we focus on instance-level open vocabulary segmentation, intending to expand a segmenter for instance-wise novel categories without mask annotations. We investigate a simple yet effective framework with the help of image captions, focusing on exploiting thousands of object nouns in captions to discover instances of novel classes. Rather than adopting pretrained caption models or using massive caption datasets with complex pipelines, we propose an end-to-end solution from two aspects: caption grounding and caption generation. In particular, we devise a joint Caption Grounding and Generation (CGG) framework based on a Mask Transformer baseline. The framework has a novel grounding loss that performs explicit and implicit multi-modal feature alignments. We further design a lightweight caption generation head to allow for additional caption supervision. We find that grounding and generation complement each other, significantly enhancing the segmentation performance for novel categories. We conduct extensive experiments on the COCO dataset with two settings: Open Vocabulary Instance Segmentation (OVIS) and Open Set Panoptic Segmentation (OSPS). The results demonstrate the superiority of our CGG framework over previous OVIS methods, achieving a large improvement of 6.8% mAP on novel classes without extra caption data. Our method also achieves over 15% PQ improvements for novel classes on the OSPS benchmark under various settings.

Nearest-Neighbor (NN) classification has been proven as a simple and effective approach for few-shot learning. The query data can be classified efficiently by finding the nearest support class based on features extracted by pretrained deep models. However, NN-based methods are sensitive to the data distribution and may produce false prediction if the samples in the support set happen to lie around the distribution boundary of different classes. To solve this issue, we present P3DC-Shot, an improved nearest-neighbor based few-shot classification method empowered by prior-driven data calibration. Inspired by the distribution calibration technique which utilizes the distribution or statistics of the base classes to calibrate the data for few-shot tasks, we propose a novel discrete data calibration operation which is more suitable for NN-based few-shot classification. Specifically, we treat the prototypes representing each base class as priors and calibrate each support data based on its similarity to different base prototypes. Then, we perform NN classification using these discretely calibrated support data. Results from extensive experiments on various datasets show our efficient non-learning based method can outperform or at least comparable to SOTA methods which need additional learning steps.