The detection of human body and its related parts (e.g., face, head or hands) have been intensively studied and greatly improved since the breakthrough of deep CNNs. However, most of these detectors are trained independently, making it a challenging task to associate detected body parts with people. This paper focuses on the problem of joint detection of human body and its corresponding parts. Specifically, we propose a novel extended object representation that integrates the center location offsets of body or its parts, and construct a dense single-stage anchor-based Body-Part Joint Detector (BPJDet). Body-part associations in BPJDet are embedded into the unified representation which contains both the semantic and geometric information. Therefore, BPJDet does not suffer from error-prone association post-matching, and has a better accuracy-speed trade-off. Furthermore, BPJDet can be seamlessly generalized to jointly detect any body part. To verify the effectiveness and superiority of our method, we conduct extensive experiments on the CityPersons, CrowdHuman and BodyHands datasets. The proposed BPJDet detector achieves state-of-the-art association performance on these three benchmarks while maintains high accuracy of detection. Code will be released to facilitate further studies.

Most recent head pose estimation (HPE) methods are dominated by the Euler angle representation. To avoid its inherent ambiguity problem of rotation labels, alternative quaternion-based and vector-based representations are introduced. However, they both are not visually intuitive, and often derived from equivocal Euler angle labels. In this paper, we present a novel single-stage keypoint-based method via an {\it intuitive} and {\it unconstrained} 2D cube representation for joint head detection and pose estimation. The 2D cube is an orthogonal projection of the 3D regular hexahedron label roughly surrounding one head, and itself contains the head location. It can reflect the head orientation straightforwardly and unambiguously in any rotation angle. Unlike the general 6-DoF object pose estimation, our 2D cube ignores the 3-DoF of head size but retains the 3-DoF of head pose. Based on the prior of equal side length, we can effortlessly obtain the closed-form solution of Euler angles from predicted 2D head cube instead of applying the error-prone PnP algorithm. In experiments, our proposed method achieves comparable results with other representative methods on the public AFLW2000 and BIWI datasets. Besides, a novel test on the CMU panoptic dataset shows that our method can be seamlessly adapted to the unconstrained full-view HPE task without modification.

Each student matters, but it is hardly for instructors to observe all the students during the courses and provide helps to the needed ones immediately. In this paper, we present StuArt, a novel automatic system designed for the individualized classroom observation, which empowers instructors to concern the learning status of each student. StuArt can recognize five representative student behaviors (hand-raising, standing, sleeping, yawning, and smiling) that are highly related to the engagement and track their variation trends during the course. To protect the privacy of students, all the variation trends are indexed by the seat numbers without any personal identification information. Furthermore, StuArt adopts various user-friendly visualization designs to help instructors quickly understand the individual and whole learning status. Experimental results on real classroom videos have demonstrated the superiority and robustness of the embedded algorithms. We expect our system promoting the development of large-scale individualized guidance of students.

Domain adaptive object detection (DAOD) aims to alleviate transfer performance degradation caused by the cross-domain discrepancy. However, most existing DAOD methods are dominated by computationally intensive two-stage detectors, which are not the first choice for industrial applications. In this paper, we propose a novel semi-supervised domain adaptive YOLO (SSDA-YOLO) based method to improve cross-domain detection performance by integrating the compact one-stage detector YOLOv5 with domain adaptation. Specifically, we adapt the knowledge distillation framework with the Mean Teacher model to assist the student model in obtaining instance-level features of the unlabeled target domain. We also utilize the scene style transfer to cross-generate pseudo images in different domains for remedying image-level differences. In addition, an intuitive consistency loss is proposed to further align cross-domain predictions. We evaluate our proposed SSDA-YOLO on public benchmarks including PascalVOC, Clipart1k, Cityscapes, and Foggy Cityscapes. Moreover, to verify its generalization, we conduct experiments on yawning detection datasets collected from various classrooms. The results show considerable improvements of our method in these DAOD tasks. Our code is available on \url{https://github.com/hnuzhy/SSDA-YOLO}.

Data-efficient learning on graphs (GEL) is essential in real-world applications. Existing GEL methods focus on learning useful representations for nodes, edges, or entire graphs with ``small'' labeled data. But the problem of data-efficient learning for subgraph prediction has not been explored. The challenges of this problem lie in the following aspects: 1) It is crucial for subgraphs to learn positional features to acquire structural information in the base graph in which they exist. Although the existing subgraph neural network method is capable of learning disentangled position encodings, the overall computational complexity is very high. 2) Prevailing graph augmentation methods for GEL, including rule-based, sample-based, adaptive, and automated methods, are not suitable for augmenting subgraphs because a subgraph contains fewer nodes but richer information such as position, neighbor, and structure. Subgraph augmentation is more susceptible to undesirable perturbations. 3) Only a small number of nodes in the base graph are contained in subgraphs, which leads to a potential ``bias'' problem that the subgraph representation learning is dominated by these ``hot'' nodes. By contrast, the remaining nodes fail to be fully learned, which reduces the generalization ability of subgraph representation learning. In this paper, we aim to address the challenges above and propose a Position-Aware Data-Efficient Learning framework for subgraph neural networks called PADEL. Specifically, we propose a novel node position encoding method that is anchor-free, and design a new generative subgraph augmentation method based on a diffused variational subgraph autoencoder, and we propose exploratory and exploitable views for subgraph contrastive learning. Extensive experiment results on three real-world datasets show the superiority of our proposed method over state-of-the-art baselines.

There still remains an extreme performance gap between Vision Transformers (ViTs) and Convolutional Neural Networks (CNNs) when training from scratch on small datasets, which is concluded to the lack of inductive bias. In this paper, we further consider this problem and point out two weaknesses of ViTs in inductive biases, that is, the spatial relevance and diverse channel representation. First, on spatial aspect, objects are locally compact and relevant, thus fine-grained feature needs to be extracted from a token and its neighbors. While the lack of data hinders ViTs to attend the spatial relevance. Second, on channel aspect, representation exhibits diversity on different channels. But the scarce data can not enable ViTs to learn strong enough representation for accurate recognition. To this end, we propose Dynamic Hybrid Vision Transformer (DHVT) as the solution to enhance the two inductive biases. On spatial aspect, we adopt a hybrid structure, in which convolution is integrated into patch embedding and multi-layer perceptron module, forcing the model to capture the token features as well as their neighboring features. On channel aspect, we introduce a dynamic feature aggregation module in MLP and a brand new "head token" design in multi-head self-attention module to help re-calibrate channel representation and make different channel group representation interacts with each other. The fusion of weak channel representation forms a strong enough representation for classification. With this design, we successfully eliminate the performance gap between CNNs and ViTs, and our DHVT achieves a series of state-of-the-art performance with a lightweight model, 85.68% on CIFAR-100 with 22.8M parameters, 82.3% on ImageNet-1K with 24.0M parameters. Code is available at https://github.com/ArieSeirack/DHVT.

我们将点隶属关系引入特征Upsmpling，这一概念描述了每个上采样点的隶属关系到具有语义相似性的本地解码器特征点形成的语义群集。通过重新思考点的隶属关系，我们提出了一种通用公式，用于产生上采样内核。内核不仅鼓励语义平滑度，还鼓励上采样的特征图中的边界清晰度。此类属性对于某些密集的预测任务（例如语义分割）特别有用。我们公式的关键思想是通过比较每个编码器特征点与解码器特征的空间相关局部区域之间的相似性来生成相似性感知的内核。通过这种方式，编码器特征点可以作为提示，以告知UPS采样特征点的语义集群。为了体现该配方，我们进一步实例化了轻巧的增加采样算子，称为相似性 - 吸引点隶属关系（SAPA），并研究其变体。 SAPA会在许多密集的预测任务上邀请一致的性能改进，包括语义分割，对象检测，深度估计和图像垫。代码可用：https：//github.com/poppinace/sapa

我们考虑在密集预测中进行任务无关功能的问题上采样，在该预测中，需要进行更新的操作员来促进诸如语义细分和详细信息敏感任务（例如图像矩阵）等区域敏感任务。现有的UP采样运算符通常可以在两种类型的任务中都能很好地工作，但两者兼而有之。在这项工作中，我们介绍了淡入淡出的淡出，插件和任务不合时宜的Upplaping Operator。淡出从三个设计选择中受益：i）考虑编码器和解码器功能在增加内核的过程中共同进行； ii）有效的半换档卷积操作员，可以对每个特征点如何有助于上采样内核进行粒状控制； iii）依赖解码器的门控机制，可增强细节描述。我们首先研究了淡出在玩具数据上的淡采样属性，然后在大规模的语义分割和图像垫子上对其进行评估。尤其是，淡淡的淡出通过在不同任务中持续优于最近的动态上采样操作员，从而揭示了其有效性和任务不足的特征。它还可以很好地跨越卷积和变压器架构，而计算开销很少。我们的工作还提供了有关使任务不合时宜的提升的深入见解。代码可在以下网址找到：http：//lnkiy.in/fade_in

盲级超分辨率（SR）旨在从低分辨率（LR）图像中恢复高质量的视觉纹理，通常通过下采样模糊内核和添加剂噪声来降解。由于现实世界中复杂的图像降解的挑战，此任务非常困难。现有的SR方法要么假定预定义的模糊内核或固定噪声，这限制了这些方法在具有挑战性的情况下。在本文中，我们提出了一个用于盲目超级分辨率（DMSR）的降解引导的元修复网络，该网络促进了真实病例的图像恢复。 DMSR由降解提取器和元修复模块组成。萃取器估计LR输入中的降解，并指导元恢复模块以预测恢复参数的恢复参数。 DMSR通过新颖的降解一致性损失和重建损失共同优化。通过这样的优化，DMSR在三个广泛使用的基准上以很大的边距优于SOTA。一项包括16个受试者的用户研究进一步验证了现实世界中的盲目SR任务中DMSR的优势。

利用TRIMAP引导和融合多级功能是具有像素级预测的基于Trimap的垫子的两个重要问题。为了利用Trimap指导，大多数现有方法只需将TRIMAPS和图像连接在一起，以馈送深网络或应用额外的网络以提取更多的TRIMAP指导，这符合效率和效率之间的冲突。对于新兴的基于内容的特征融合，大多数现有的消光方法仅关注本地特征，这些功能缺乏与有趣对象相关的强大语义信息的全局功能的指导。在本文中，我们提出了一种由我们的Trimap引导的非背景多尺度池（TMP）模块和全球本地背景信息融合（GLF）模块组成的Trimap-Goided Feats挖掘和融合网络。考虑到Trimap提供强大的语义指导，我们的TMP模块在Trimap的指导下对有趣的对象进行了有效的特征挖掘，而无需额外参数。此外，我们的GLF模块使用我们的TMP模块开采的有趣物体的全局语义信息，以指导有效的全局本地上下文感知多级功能融合。此外，我们建立了一个共同的有趣的物体消光（CIOM）数据集，以推进高质量的图像消光。在组合物-1K测试集，Alphamatting基准和我们的CIOM测试集上的实验结果表明，我们的方法优于最先进的方法。代码和模型将很快公开发布。