Deep cross-modal hashing has gained significant attention because of its benefits, including reduced storage requirements and enhanced retrieval efficiency. Although progress has been made, existing deep cross-modal hashing methods still face unresolved challenges. Most existing methods typically adopt Euclidean space as the embedding space to measure the semantic similarity between original samples. However, the volume of Euclidean space grows polynomially with dimension, which exacerbates the curse of dimensionality. In contrast, methods based on spherical space usually use cosine similarity as the metric, effectively mitigating the aforementioned problem by normalizing the embedding vectors. Nevertheless, such methods only considers the direction to determine the category, ignoring the uncertainty measure in the embedding space, thus having a limited ability to preserve inherent multimodal semantics. In this paper, with a novel extension of the maximum entropy distribution on the surface of a hypersphere von Mises-Fisher (vMF) distribution, a novel deep cross-modal hashing method, named Deep Stochastic Spherical Hashing (DSSH), is designed to utilize uncertain information to guide the hashing process and produce discriminative modality-invariant hash codes. Specifically, to learn explicit uncertainty in learned embedding space, the Spherical von Mises-Fisher distribution is applied for the f irst time in deep cross-modal hashing, where the direction of the sample embedding controls its position on the hyper sphere, thereby preventing its semantic content, and its norm parameterizes the determinism of the distribution. In addition, stochastic spherical von Mises–Fisher loss is proposed to preserve the mode-specific semantic information of the sample, achieving the alignment of different modalities and semantic embeddings. Extensive experiments on four benchmark datasets show that our DSSH framework outperforms existing state-of-the-art cross modal hashing methods. The source code of the experiments is available at https://github.com/QinLab-WFU/DSSH.

Cloud-induced gaps in Sea Surface Temperature (SST) pose significant challenges to climate modeling and oceanographic research by causing the loss of critical spatiotemporal data. Recently, traditional deep neural network-based methods have shown promising results by effectively utilizing rich historical data. However, when confronted with extensive gaps in SST data, methods such as CNN, LSTM, and Transformer struggle to model long-range dependencies effectively or often overlook non-salient features in the gap inpainting process. To address this, we introduce a novel approach for SST completion under large-scale missing data conditions, focusing on modeling long-range dependencies by leveraging Mamba to adaptively select essential features. We propose an innovative Mamba-based inpainting network, DINMamba, for reconstructing large missing areas in SST. Specifically, to ensure physical coherence across scales, DINMamba designs a stackable recursive hierarchical Mamba block that progressively captures both stable patterns and anomalies. Finally, the fusion of these two types of information guarantees more coherent and accurate reconstructions across extensive missing regions. Experimental results on real-world datasets demonstrate the superiority of DINMamba over several state-of-the-art (SOTA) methods.Under a$68\%$missing rate, our model achieves significant improvements, reducing$RMSE$by$34.07\%$,$34.91\%$, and$37.23\%$, enhancing$R^{2}$by$5.78\%$,$7.06\%$, and$8.17\%$, increasing$SSIM$by$26.73\%$,$28.82\%$, and$31.17\%$, and boosting$PSNR$by$4.93\%$,$5.01\%$, and$5.97\%$, across noise-to-signal (N/S) ratios of 0.1, 0.2, and 0.3, respectively. Furthermore, ablation studies validate the contribution of each component and the model’s generalization capability across different seasons.

Due to its low storage cost and high retrieval efficiency, hashing technology is popularly applied in both academia and industry, which provides an interesting solution for cross-modal similarity retrieval. However, most existing supervised cross-modal hashing methods typically view the fixed-level semantic affinity defined by manual labels as supervised signals to guide hash learning, which only represents a small subset of complex semantic relations between multi-modal samples, thus impeding the hash function learning and degrading the obtained hash codes. In the paper, by learning shared hierarchy proxies, a novel deep cross-modal hashing framework, called Deep Hierarchy-aware Proxy Hashing (DHaPH), is proposed to construct the semantic hierarchy in a data-driven manner, thereby capturing the accurate fine-grained semantic relationships and achieving small intra-class scatter and big inter-class scatter. Specifically, by regarding the hierarchical proxies as learnable ancestors, a novel hierarchy-aware proxy loss is designed to model the latent semantic hierarchical structures from different modalities without prior hierarchy knowledge, in which similar samples share the same Lowest Common Ancestor (LCA) and dissimilar points have different LCA. Meanwhile, to adequately capture valuable semantic information from hard pairs, a multi-modal self-paced loss is introduced into cross-modal hashing to reweight multi-modal pairs dynamically, which enables the model to gradually focus on hard pairs while simultaneously learning universal patterns from multi-modal pairs. Extensive experiments on three available benchmark databases demonstrate that our proposed DHaPH framework outperforms the compared baselines with different evaluation metrics. The corresponding code is available athttps://github.com/QinLab-WFU/DHaPH.

Local differential privacy (LDP) has been established as a strong privacy standard for collecting sensitive information from users. Although it has attracted much research attention in recent years, the majority of existing works focus on applying LDP to frequency distribution estimation for each individual value in a discrete domain. This paper concerns the important range queries involving multiple discrete values. Till now, only a few works target this problem. They all rely on the B-ary tree to construct a uniform and hierarchical decomposition, so as to decrease the error when answering large range queries. However, the uniform splitting manner ignores the properties of decomposed sub-domains and processes them equally without preferences, which leads to significant performance penalty.In this paper, we tackle the problem head on: our proposal, privNUD, is a novel domain hierarchical decomposition mechanism. It dynamically decomposes each domain with a tailored granularity into some sub-domains, which sensitively considers the potential chances to answer one range query. The issue of granularity is carefully analyzed for better performance. It also can smartly prune the sub-domains with small frequencies. Besides, an adaptive user allocation technique is designed to dynamically decide the scale of users that are involved in each sub-domain’s frequency estimation. Extensive experiments using real and synthetic datasets demonstrate that privNUD achieves significantly higher result accuracy compared to the up-to-date solutions.

Remote sensing cross-modal image-text retrieval has attracted increasing attention due to its important roles in multiple domains. Existing methods perform salient modeling for the feature that has high relevance between different modalities. However, most works consider the relevance between different modalities but ignore the irrelevance between different modalities, resulting in incomplete modeling of the relevance and irrelevance between different modalities. In this paper, we propose a Relevance and Irrelevance Considered Subspace Mapping Neural Networks (RIR-SMNNs) to simultaneously consider the relevance and irrelevance between different modalities. Specifically, we first utilize Multiscale Image Feature Extraction (MIFE) and Multiscale Text Feature Extraction (MTFE) to extract the multiscale feature of image and text. Then, we perform Local Space Building Module (LSB), which constructs local space that realizes scale alignment. Finally, we perform the Relevance and Irrelevance Local Space Mapping (RIRLSM) to consider the relevance and irrelevance of different modalities in multiple spaces. Experimental results on several remote sensing datasets demonstrate our model outperforms the state-of-the-art approaches.

With the development of deep neural networks, especially generation networks, gray image coloring technology has made great progress. As one of the fields, remote sensing image colorization needs to be solved urgently. This is because remote sensing images cannot obtain clear color images due to the limitations of shooting equipment and transmission equipment. Compared with ordinary images, remote sensing images are characterized by the uneven spatial distribution of objects, therefore, it is a great challenge to ensure the spatial consistency of coloring. To embrace this challenge, we propose a new joint stream DCGAN including a micro stream and a macro stream, in which the latter is set as a prior to constrain the former for colorization. In addition, the Low-level Correlation Feature Extraction (LCFE) module is proposed to obtain the salient shallow detail feature with global correlation, which is used to enhance the global constraints as well as supplement the low-level information to the micro stream. What's more, we propose the Gated Selection (GSM) module by selecting useful information using a gated scheme to fuse features from two streams appropriately. Comprehensive comparison and ablation experiments are implemented and verify the proposed method performs surpasses other methods in both qualitative and quantitative metrics.

The accuracy of the semantic segmentation results of ships is of great significance to coastline navigation, resource management, and territorial protection. Although the ship semantic segmentation method based on deep learning has made great progress, there is still the problem of not exploring the correlation between the targets. In order to avoid the above problems, this paper designed a multi-scale graph convolutional network and dynamic iterative class loss for ship segmentation in remote sensing images to generate more accurate segmentation results. Based on DeepLabv3+, our network uses deep convolutional networks and atrous convolutions for multi-scale feature extraction. In particular, for multi-scale semantic features, we propose to construct a Multi-Scale Graph Convolution Network (MSGCN) to introduce semantic correlation information for pixel feature learning by GCN, which enhances the segmentation result of ship objects. In addition, we propose a Dynamic Iterative Class Loss (DICL) based on iterative batch-wise class rectification instead of pre-computing the fixed weights over the whole dataset, which solves the problem of imbalance between positive and negative samples. We compared the proposed algorithm with the most advanced deep learning target detection methods and ship detection methods and proved the superiority of our method. On a High-Resolution SAR Images Dataset [1], ship detection and instance segmentation can be implemented well.

The semantic segmentation of frazil ice and anchor ice is of great significance for river management, ship navigation, and ice hazard forecasting in cold regions. Especially, distinguishing frazil ice from sediment-carrying anchor ice can increase the estimation accuracy of the sediment transportation capacity of the river. Although the river ice semantic segmentation methods based on deep learning has achieved great prediction accuracy, there is still the problem of insufficient feature extraction. To address this problem, we proposed a Fine-Grained River Ice Semantic Segmentation (FGRIS) based on attentive features and enhancing feature fusion to deal with these challenges. First, we propose a Dual-Attention Mechanism (DAM) method, which uses a combination of channel attention features and position attention features to extract more comprehensive semantic features. Then, we proposed a novel Branch Feature Fusion (BFF) module to bridge the semantic feature gap between high-level feature semantic features and low-level semantic features, which is robust to different scales. Experimental results conducted on Alberta River Ice Segmentation Dataset demonstrate the superiority of the proposed method.

In this work, we aim to investigate the practical task of flexible fashion search with attribute manipulation, where users can retrieve the target fashion items by replacing the unwanted attributes of an available query image with the desired ones (e.g., changing the collar attribute from v-neck to round). Although several pioneer efforts have been dedicated to fulfilling the task, they mainly ignore the potential of generative models in enhancing the visual understanding of target fashion items. To this end, we propose an end-to-end generative attribute manipulation scheme, which consists of a generator and a discriminator. The generator works on producing the prototype image that meets the user's requirement of attribute manipulation over the query image with the regularization of visual-semantic consistency and pixel-wise consistency. Besides, the discriminator aims to jointly fulfill the semantic learning towards correct attribute manipulation and adversarial metric learning for fashion search. Pertaining to the adversarial metric learning, we provide two general paradigms: the pair-based scheme and the triplet-based scheme, where the fake generated prototype images that closely resemble the ground truth images of target items are incorporated as hard negative samples to boost the model performance. Extensive experiments on two real-world datasets verify the effectiveness of our scheme.