由于癌症样品收集和注释的难度,宫颈癌数据集通常表现出长尾数据分布。当训练检测器以检测WSI(整个切片图像)中的癌细胞时,从TCT(ThinPrep细胞学测试)样品捕获的样品时,头部类别(例如正常细胞和炎性细胞)通常比尾巴类别数量更大。 (例如癌细胞)。对象检测中的大多数现有最新的长尾学习方法将重点放在类别分布统计上,以解决长尾方案中的问题,而无需考虑每个样本的“硬度”。为了解决这个问题,在这项工作中,我们提出了一个Grad-libra损失,该损失利用梯度动态校准每个样品的硬度程度,以使不同类别的硬度度重新平衡正面和负样品的梯度。因此,我们的损失可以帮助探测器更加重视头部和尾部类别中的这些硬样品。在长尾的TCT WSI图像数据集上进行了广泛的实验表明,主流检测器,例如对使用我们建议的梯度损失训练的训练,重新点,FCO,ATSS,YOLOF等的地图比使用跨透明分类损失训练的地图要高得多(7.8%)。
translated by 谷歌翻译
语言是人类交流的主要工具,其中幽默是最有吸引力的部分之一。使用计算机,又称自然语言生成(NLG)的人类产生自然语言,已广泛用于对话系统,聊天机器人,机器翻译以及计算机AID创建,例如Idea Generations,剧本。但是,自然语言的幽默方面相对不足,尤其是在预训练的语言模型时代。在这项工作中,我们旨在初步测试NLG是否可以像人类一样产生幽默。我们构建了一个新的数据集,该数据集由众多数字化的中国可笑的串扰脚本(称为c $^3 $简称),该脚本适用于1800年代以来名为“ Xiangsheng”的流行中国表演艺术。 (为了方便非中国扬声器,我们在本文中称为“ Xiangsheng”的“ Crosstalk”。)我们基准了各种一代方法,包括训练seq2seq,微调中级PLMS和大型PLMS(大型PLMS)(有无微调)。此外,我们还进行了人类评估,表明1)大规模预处理在很大程度上提高了串扰的产生质量; 2)即使是从最佳PLM产生的脚本也远非我们的期望,只有65%的人类创建的串扰质量。我们得出结论,使用大型PLM可以在很大程度上改善幽默的产生,但仍处于起步阶段。 \ url {https://github.com/anonno2/crosstalk-generation}公开可用数据和基准代码。
translated by 谷歌翻译
To balance the annotation labor and the granularity of supervision, single-frame annotation has been introduced in temporal action localization. It provides a rough temporal location for an action but implicitly overstates the supervision from the annotated-frame during training, leading to the confusion between actions and backgrounds, i.e., action incompleteness and background false positives. To tackle the two challenges, in this work, we present the Snippet Classification model and the Dilation-Erosion module. In the Dilation-Erosion module, we expand the potential action segments with a loose criterion to alleviate the problem of action incompleteness and then remove the background from the potential action segments to alleviate the problem of action incompleteness. Relying on the single-frame annotation and the output of the snippet classification, the Dilation-Erosion module mines pseudo snippet-level ground-truth, hard backgrounds and evident backgrounds, which in turn further trains the Snippet Classification model. It forms a cyclic dependency. Furthermore, we propose a new embedding loss to aggregate the features of action instances with the same label and separate the features of actions from backgrounds. Experiments on THUMOS14 and ActivityNet 1.2 validate the effectiveness of the proposed method. Code has been made publicly available (https://github.com/LingJun123/single-frame-TAL).
translated by 谷歌翻译
传统的像素图像攻击算法对防御算法的鲁棒性不佳,即应用防御算法时的攻击强度急剧下降。尽管生成对抗网络(GAN)可以通过综合更有意义的纹理模式来部分解决此问题,但主要限制是现有生成器只能生成特定比例的图像。在本文中,我们提出了一种基于无规模的攻击算法,该算法将全球具有语义上有意义的对抗模式综合到具有任意尺度的图像。我们的生成攻击方法始终优于各种攻击设置上的最新方法,即所提出的方法在很大程度上降低了各种图像分类,对象检测和实例分段算法在不同的高级防御方法下的性能。
translated by 谷歌翻译
这项工作侧重于老年人活动认可的任务,这是一个充满挑战的任务,因为在老年活动中的个人行为和人体对象互动存在。因此,我们试图通过专注地融合多模态特征来有效地聚合来自RGB视频和骨架序列的判别信息和与RGB视频和骨架序列的交互。最近,通过利用从挤压和激励网络(Senet)延伸的非线性关注机制来提出一些非线性多模态融合方法。灵感来自于此,我们提出了一种新颖的扩张 - 挤压激励融合网络(ESE-FN),有效地解决了老年活动识别问题,从而了解模态和渠道 - 明智的膨胀 - 挤压(ESE)注意到术语融合模态和通道方面的多模态特征。此外,我们设计了一种新的多模态损耗(ML),以通过在单个模态的最小预测损失与预测损失之间添加差异之间的差异来保持单模特征和融合多模态特征之间的一致性。融合的方式。最后,我们对最大的老年活动数据集进行实验,即ETRI-Activity3D(包括110,000多个视频和50个类别),以证明建议的ESE-FN与状态相比实现了最佳准确性 - 最新方法。此外,更广泛的实验结果表明,所提出的ESE-FN在正常动作识别任务方面也与其他方法相媲美。
translated by 谷歌翻译
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.
translated by 谷歌翻译
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.
translated by 谷歌翻译
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.
translated by 谷歌翻译
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.
translated by 谷歌翻译
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.
translated by 谷歌翻译