Learning multi-scale deep features for person re-identification

Thorax disease classification with attention guided convolutional neural network

Lunar craters and rilles are significant topographic features on the lunar surface that will play an essential role in future research on space energy resources and geological evolution. However, previous studies have shown low efficiency in detecting lunar impact craters and poor accuracy in detecting lunar rilles. There is no complete automated identification method for lunar features to explore space energy resources further. In this paper, we propose a new specific deep-learning method called high-resolution global–local networks (HR-GLNet) to explore craters and rilles and to discover space energy simultaneously. Based on the GLNet network, the ResNet structure in the global branch is replaced by HRNet, and the residual network and FPN are the local branches. Principal loss function and auxiliary loss function are used to aggregate global and local branches. In experiments, the model, combined with transfer learning methods, can accurately detect lunar craters, Mars craters, and lunar rilles. Compared with other networks, such as UNet, ERU-Net, HRNet, and GLNet, GL-HRNet has a higher accuracy (88.7 ± 8.9) and recall rate (80.1 ± 2.7) in lunar impact crater detection. In addition, the mean absolute error (MAE) of the GL-HRNet on global and local branches is 0.0612 and 0.0429, which are better than the GLNet in terms of segmentation accuracy and MAE. Finally, by analyzing the density distribution of lunar impact craters with a diameter of less than 5 km, it was found that: (i) small impact craters in a local area of the lunar north pole and highland (5°–85°E, 25°–50°S) show apparent high density, and (ii) the density of impact craters in the Orientale Basin is not significantly different from that in the surrounding areas, which is the direction for future geological research.

Two-phase self-supervised pretraining for object re-identification

Fully-automated person re-identification in multi-camera surveillance system with a robust kernel descriptor and effective shadow removal method

Currently, the mainstream unsupervised method uses a clustering algorithm to cluster unlabeled data and generate labels for training samples based on the clustering results. The critical step is to obtain the features. Most unsupervised methods are based on single-branch networks. Still, multi-branch networks that fusion local and global features have been proved to improve supervised effectively. This paper studies the problem of unsupervised person re-identification using the multi-branch network. The goal is to extract more reliable feature representation through the multi-branch network and obtain a model with a more vital distinguishing ability. Specifically, an OSNet-based multi-branch network simultaneously extracts global, local, and channel features. It applies a bottom-up clustering algorithm based on the hierarchy to create labels for unlabeled training samples and uses Softmax-Triplet joint loss to optimize the model. We verify the proposed method on two benchmark re-ID datasets, such as the Market-1501 and DukeMTMC-reID datasets. Compared with the baseline method, the accuracy of Rank-1 and mAP are improved by 5.5 and 12.6% on Market-1501, and 5.5 and 7.6% on DukeMTMC-reID.

Due to the scarcity of fault samples in real-world industrial scenarios, few-shot fault diagnosis (FSFD) has attracted increasing attention, as it is vital for ensuring industrial safety and engineering reliability. However, existing metrics-based meta learning approaches generally calculate fault similarity relying on global pairwise, which insufficiently exploit fault information and thus limit discrimination among fault types. To address the insensitivity to buried fault information in complete processes, we propose a novel framework called the Local-Global Consistency Relation Network (LGCRN). The framework captures more comprehensive fault feature information through two components: the global branch, which focuses on macro-information involving all join process units, and the local branch, which emphasizes finer granularity from specific units. Additionally, a local-global alignment loss is utilized to optimize LGCRN, where self-cross relation improves the discriminability and stability of fault features by maintaining consistency between local and global branches. The self-cross relation comprises self-sample relation, ensuring consistency within the same sample at different granularities, and cross-sample relation, maintaining consistency across samples within the same class. Experiments on two benchmarks and a real semiconductor process demonstrate the feasibility and superiority of the proposed method, confirming its effectiveness in addressing limited-sample industrial fault diagnosis tasks and enabling timely maintenance crucial for operational safety in real-world scenarios.

Person re-identification (Re-ID) is crucial in intelligent surveillance, requiring precise identification of individuals across multiple camera viewpoints. Traditional distance-based methods, such as Euclidean and Cosine, struggle with challenges like posture variations and occlusions, limiting their effectiveness. This study explores deep metric learning models, specifically Siamese and Triplet networks, to improve Re-ID performance. We evaluate these methods on the Market-1501 dataset using Cumulative Matching Characteristic (CMC) and Cumulative Distribution Function (CDF) curves. Our findings reveal that the Triplet network outperforms traditional approaches at higher ranks, achieving Rank-5 accuracy of 78.6% and Rank-10 accuracy of 93%, while its Rank-1 accuracy remains low (0.06%). In contrast, Euclidean and Cosine distances show poor Rank-1 performance (2% and 0.30%, respectively), highlighting their limitations. Additionally, incorporating VGG16 enhances feature extraction, improving recognition by capturing fine-grained spatial details. This comparative study highlights the effectiveness of deep metric learning and underscores its potential for real-world surveillance applications. However, the computational demands of deep networks present challenges for real-time deployment. Future research should focus on optimizing model efficiency, reducing computational costs, and extending evaluations to real-time scenarios.

Person re-identification with part prediction alignment

Person re-identification (Re-ID) aims to retrieve a person of interest across multiple nonoverlapping cameras. In the last few years, the construction of aerial person Re-ID datasets has been appealing because visual surveillance through unmanned aerial vehicle (UAV) platforms has become very valuable in real-world scenarios. However, great differences are exhibited between the pedestrian images captured by ground cameras and those captured by UAVs. Person Re-ID methods based on ground person images have difficulty when performing Re-ID based on aerial person images. In this paper, we first propose a novel meta-transfer learning method for person Re-ID in aerial imagery; this approach trains a generalisable Re-ID model to learn discriminative feature representations for aerial person images. Specifically, a meta-learning strategy is introduced to study a feature extractor, and a transfer learning strategy is introduced to utilise and further improve the acquired meta-knowledge. To overcome the convergence speed and recognition accuracy reductions caused by the presence of difficult categories in the given dataset, we propose a learning strategy based on curriculum sampling that is harmonised with our meta-transfer learning framework. In addition, a new metric formulation of sample similarity is introduced based on Mahalanobis distance to improve the optimisation of the model. Extensive comparative evaluation experiments are conducted on the large-scale aerial Re-ID dataset, and the results obtained show that our method achieves a Rank-1 accuracy of 63.63 $$\%$$ and a mean average precision (mAP) of 38.02 $$\%$$ , demonstrating its potential for completing person Re-ID in aerial images. Ablation studies also validate that each component contributes to improving the performance of the model.

Smart city is an area where the Internet of things is used effectively with sensors. The data used by smart city can be collected through the cameras, sensors etc. Intelligent video surveillance (IVS) systems integrate multiple networked cameras for automatic surveillance purposes. Such systems can analyze and monitor video data and perform automatic functions required by users. This study performed main path analysis (MPA) to explore the development trends of IVS research. First, relevant articles were retrieved from the Web of Science database. Next, MPA was performed to analyze development trends in relevant research, and g-index and h-index values were analyzed to identify influential journals. Cluster analysis was then performed to group similar articles, and Wordle was used to display the key words of each group in word clouds. These key words served as the basis for naming their corresponding groups. Data mining and statistical analysis yielded six major IVS research topics, namely video cameras, background modeling, closed-circuit television, multiple cameras, person reidentification, and privacy, security, and protection. These topics can boost the future innovation and development of IVS technology and contribute to smart transportation, smart city, and other applications. According to the study results, predictions were made regarding developments in IVS research to provide recommendations for future research.

Unsupervised domain adaptation (UDA) aims to mitigate the domain shift that occurs when transferring knowledge from a labeled source domain to an unlabeled target domain. While it has been studied for application in unsupervised person re-identification (ReID), the relations of feature distribution across the source and target domains remain underexplored, as they either ignore the local relations or omit the in-depth consideration of negative transfer when two domains do not share identical label spaces. In light of the above, this paper presents an innovative part-aware progressive adaptation network (PPAN) that exploits global and local relations for UDA-based ReID across domains. A multi-branch network is developed that explicitly learns discriminative feature representation from both whole-body images and body-part images under the supervision of a labeled source domain. Within each network branch, an independent UDA constraint is designed that aligns the global and local feature distributions from a labeled source domain with those of an unlabeled target domain. In addition, a novel progressive adaptation strategy (PAS) is designed that effectively alleviates the negative influence of outlier source identities. The proposed unsupervised ReID model is evaluated on five widely used datasets (Market-1501, DukeMTMC-reID, CUHK03, VIPeR and PRID), and experimental results demonstrate its superior robustness and effectiveness relative to state-of-the-art approaches.

In person re-identification problem, learning distinctive features to differentiate one person from the others is one of the key factors to improve the result. In this paper, we propose the Multi-Branch Network with Dynamically Matching (MNDM) algorithm, which has a multi-branch deep network architecture consisting of three branches: one for learning global features, and two for local features. In the one branch learning local features, where the bounding box is split into horizontal stripes, the model applies a dynamically matching algorithm to efficiently matching these parts addressing the misalignment issue caused by imperfect detection bounding boxes. Several experiments are conducted on Market1501, CUHK03 and DukeMTMC. All the results that demonstrate the proposed model significantly outperforms the previous state-of-the-art.

State-of-the-art person re-identification (ReID) models use Convolutional Neural Networks (CNN) for feature extraction and comparison. Often these models fail to recognize all the intra- and inter-class variations that emerge in person ReID, making it harder to discriminate between data subjects. In this paper we seek to reduce these problems and improve performance by combining two state-of-the-art models. We use the Omni-Scale Network (OSNet) as our CNN to test the Market1501 and DukeMTMC-ReID datasets for person ReID. To fully utilize the potential of these datasets, we apply the spatialtemporal constraint which extracts the camera ID and timestamp from each image to form a distribution. We combine these two methods to create a hybrid model titled Spatial-Temporal OmniScale Network (st-OSNet). Our model attains a Rank-1 (R1) accuracy of 98.2% and mean average precision (mAP) of 92.7% for the Market1501 dataset. For the DukeMTMC-reID dataset our model achieves 94.3% R1 and 86.1% mAP, hereby surpassing the results of OSNet by a large margin for both datasets (94.3%, 86.4%, 88.4%, 76.1%, respectively).

Person re-identification based on improved attention mechanism and global pooling method

In recent years, person reidentification has received growing attention with the increasing popularity of intelligent video surveillance. This is because person reidentification is critical for human tracking with multiple cameras. Recently, keep it simple and straightforward (KISS) metric learning has been regarded as a top level algorithm for person reidentification. The covariance matrices of KISS are estimated by maximum likelihood (ML) estimation. It is known that discriminative learning based on the minimum classification error (MCE) is more reliable than classical ML estimation with the increasing of the number of training samples. When considering a small sample size problem, direct MCE KISS does not work well, because of the estimate error of small eigenvalues. Therefore, we further introduce the smoothing technique to improve the estimates of the small eigenvalues of a covariance matrix. Our new scheme is termed the minimum classification error-KISS (MCE-KISS). We conduct thorough validation experiments on the VIPeR and ETHZ datasets, which demonstrate the robustness and effectiveness of MCE-KISS for person reidentification.