Sample augmentation is crucial for improving land cover classification performance when the samples are limited. However, the traditional sample augmentation approach concentrates on enlarging the quantity of sample via generation and synthetic technique directly, the sample quality is usually neglected. In this article, we propose a novel sample augmentation approach with threshold estimation (SATE) to improve both the quantity and quality of samples for hyperspectral remotely sensed image (HRSI) classification. Firstly, a threshold estimation algorithm (TEA) is proposed to identify high-confidence potential samples from the initial classification map by utilizing the prediction probabilities of different classes. Second, a semi-variational model is employed to detect and correct pseudo-labels in the spatial domain, further enhancing the quality of selected potential samples. Finally, a farthest point sampling (FPS) algorithm optimizes sample distribution in the spectral domain, improving representation for intra-class heterogeneity. Experimental results based on four real HRSIs and compared with eight state-of-the-art few-shot-based methods verify the feasibility and superiority of the proposed SATE approach. The improvement achieved by our proposed approach is about 0.79% ~ 4.31% in terms of the overall accuracy. Code is available at https://github.com/ImgSciGroup/SATE.

Achieving satisfactory land cover classification performance with high-resolution remote sensing images (HRSIs) usually requires sufficient samples for a supervised classifier. However, labeling sufficient samples is labor-intensive and time-consuming. In this article, a Novel Sample Augmentation Approach (NSAA) is proposed to synthesize new samples and improve classification accuracies for HRSI when initial known samples are very limited. First, a very small sample set of each class is prepared manually for the algorithm’s initialization. Second, a sample generator based on normal cloud model is proposed, and an adaptive region growing algorithm is suggested to explore some potential samples around a known sample for parameter estimation of the sample generator. Third, to further refine the generated samples around an initial known sample, a near-to-far space constraint strategy is proposed based on the K-means clustering algorithm to improve the quality of the generated samples. The proposed sample augmentation approach is incorporated with a classifier iteratively, and a sample balancing strategy is suggested in the iterative progress. Experiment results based on six real HRSIs and compared with eight state-of-the-art methods demonstrate the feasibility and superiorities of the proposed sample augmentation approach. Moreover, the reliability and robustness of the generated samples are verified by popular deep-learning networks and typical traditional classifiers. The improvement achieved by our proposed approach is about 0.12% – 0.95% in terms of the overall accuracy.

Accurate cellular network traffic prediction is crucial for intelligent network planning and management in 6G. However, the non-stationary characteristics of cellular network traffic present significant challenges when training deep neural networks for traffic forecasting. To address this issue, we propose a two-stage deep learning framework, JO-DPNet, based on Bayesian joint parameter optimization, which integrates data decomposition techniques with Bayesian joint optimization to effectively mitigate the adverse impacts of non-stationarity and error accumulation on prediction accuracy. In the first stage, a data decomposition module uses Variational Mode Decomposition (VMD) to decompose the original data into network traffic subset series(TSS), thereby alleviating the negative effects of non-stationarity. In the second stage, a prediction and construction module leverages a bi-directional LSTM (Bi-LSTM) network to extract deep spatial-temporal features from the TSS in a bidirectional manner. A fully connected layer then captures the relationships between the TSS and reconstructs the predicted results into the final output. The JO module employs the Tree-structured Parzen Estimator based Bayesian optimization algorithm(TP-BO) simultaneously determines the optimal VMD mode number k and the hyperparameters of the Bi-LSTM network through probabilistic surrogate model. Extensive experiments on three real-world cellular traffic datasets demonstrate that the proposed method significantly mitigates the non-stationary characteristics of the traffic data. Compared to state-of-the-art methods, JO-DPNet achieves reductions in MAE by 29%, 3%, and 19% for three type prediction tasks on the Telecom Italia dataset. The source code is available to the public at: https://github.com/VicentZhang259/JO-DPNet.

Supervised classification with hyperspectral remote-sensing images (HRSIs) plays an important role in practical applications. However, labeling samples with HRSIs for supervised classification is time-consuming and labor-intensive. In this letter, we propose a new sample enhancement approach to improve the classification performance of HRSIs. First, the uncertainty and representativeness of the sample are defined to achieve sample possibility measurement for each pixel, and some pixels with high possibility can be selected as candidate samples. Then, two rules related to label correlation analysis and spectral similarity are defined to further refine the candidate samples used for generating the final sample set. Finally, the above-mentioned steps are fused into an iterative algorithm to enhance and balance the training samples for each class. The feasibility of the proposed approach was verified by applying it to classification with two real HRSIs. A comparison with some typical traditional sample enhancement methods and widely used few-shot deep-learning methods indicated the advantages of the proposed approach for improving classification accuracies. The improvement achieved by our proposed approach is about 0.79% ~ 2.31% in terms of the overall accuracy (OA). The code of the proposed approach is available athttps://github.com/ImgSciGroup/2023-GRSL-SIEA.

Sample augmentation is effective for improving the supervised performance of land-cover classification with hyperspectral remote sensed image (HRSI) when the training samples are limited. However, numerous existing methods have neglected, considering the interclass-imbalance problem in the process of sample augmentation. In this work, new sample generation and sample balance strategies were promoted and simultaneously combined into an iteration for balancing and improving classification performance with HRSI. First, a sample augmentation with superpixel’s constraint (SASC) is designed to augment the initial training samples set to avoid the overfitting of a sample generation neural network. Second, sample generation based on generative adversarial network (SGGAN) was proposed to generate samples for each class. Then, the proposed SASC, SGGAN, and a pattern recognition neural network named 3 dimensions-convolutional neural network (3-D-CNN) are combined into an iterative classification process called iterative sample generation and balance (ISGB) for balancing the user’s accuracy for each class and optimizing the classification performance. Experiments on four widely used HRSIs are performed. The results when compared with eight state-of-the-art methods based on few-shot learning and generative adversarial network (GAN) efficiently demonstrate the feasibility and superiorities of the proposed approach for improving land-cover classification performance when the initial samples are limited. Moreover, the comparisons of the standard deviation of the user’s accuracies (SDUA) demonstrated the balancing ability of the proposed approach. The code of the proposed approach is available athttps://github.com/ImgSciGroup/ISGBA.

Samples play a crucial role in the supervised classification of remote sensing images. However, labeling large samples for training a classifier or deep learning network is not only time-consuming but also labor-intensive. In this paper, a novel land cover classification with nonparametric sample augmentation is proposed to improve the performance of hyperspectral remote sensing images (HRSIs) classification. First, initial samples with limited quantity are selected randomly from the ground truth map. Second, based on the gray image, a nonparametric adaptive region generation (NARG) algorithm is developed for utilizing the contextual information around each sample. Then, an nonparametric sample augmentation algorithm is developed with NARG to explore reliable samples iteratively around each initial sample. Finally, the above steps are fused into an iterative progress to obtain the final classification map. Compared with some typical traditional methods and some widely used deep learning methods based on four real HRSIs, our proposed approach exhibits some advantages in improving the visual performance and quantitative accuracies of HRSIs classification, such as the improvement is about 2.0% ~ 10.34% for four real HRSIs in term of the overall accuracy.

Spectral-spatial features are important for ground target identification and classification with High Spatial Resolution Remotely Sensed (HSRRS) Imagery. In this paper, two novel features, named the Gaussian-Weighting Spectral (GWS) feature and the Area Shape Index (ASI) feature, are proposed to complement the deficiency of the basic image feature for land cover classification with HSRRS imagery. The proposed GWS feature is an adaptive region-based feature that aims to improve the spectral homogeneity of a local area surrounding a pixel. Additionally, it is well known that the spectral feature is inadequate for classifying HSRRS imagery. Therefore, one spatial feature called the ASI feature is proposed here to describe the relationship between the area and shape for an adaptive region around each pixel. The proposed GWS and ASI features coupled with the basic red-green-blue feature are fed into a supervised classifier to obtain the final classification map. Experiments based on four real HSRRS images demonstrate that the proposed GWS and ASI features are capable of improving classification accuracies compared with some cognate state of the art methods. Moreover, the experiments also reveal that the proposed spectral-spatial features can complement each other for enhancing the classification performance with HSRRS images.