Hyperspectral images (HSI) densely sample the world in both the space and frequency domains and, therefore, are more distinctive than RGB images. Usually, HSI needs to be calibrated to minimize the impact of various illumination conditions. The traditional way to calibrate HSI utilizes a physical reference, which involves manual operations, occlusions, and/or limits camera mobility. These limitations inspire this paper to automatically calibrate HSIs using a learning-based method. Towards this goal, a large-scale HSI calibration dataset, which has 765 high-quality HSI pairs covering diversified natural scenes and illuminations, is created. The dataset is further expanded to 7650 pairs by combining with 10 different physically measured illuminations. A spectral illumination transformer (SIT) together with an illumination attention module is proposed. Extensive benchmarks demonstrate the SoTA performance of the proposed SIT. The benchmarks also indicate that low-light conditions are more challenging than normal conditions. The dataset and codes are available online: https://github.com/duranze/Automatic-spectral-calibration-of-HSI.

This paper proposes a dynamic multi-scale spatial-temporal graph convolutional network (DS-STGCN) for traffic flow prediction . The network aims to comprehensively extract global and local dependencies in dynamic spatial-temporal data by inputting traffic network flow data to construct node feature graphs, topology graphs , and time slot feature graphs, capturing the complexity and dynamics of traffic flow. DS-STGCN interprets feature information of the traffic network from both spatial and temporal dimensions through dynamic multi-scale graph convolutional blocks. In the spatial dimension, these blocks use constraints at different levels to balance fine-grained local features and extensive global features, revealing the intrinsic structure of traffic flow data. In the temporal dimension, these blocks jointly learn with temporal convolutional blocks to capture multi-frequency time patterns and handle long sequence data, effectively extracting potential dependencies of time series . Furthermore, DS-STGCN effectively models the changing spatial-temporal relationships in road network flow by constructing dynamically adaptive updated adjacency tensors, generating dynamic graph structures to address the challenge of changing spatial-temporal relationships in the transportation system. Experimental results show that our method significantly outperforms other competing methods on five real traffic datasets (PEMS03, PEMS04, PEMS07, PEMS08 and METR-LA).

Discovering the novel associations of biomedical entities is of great significance and can facilitate not only the identification of network biomarkers of disease but also the search for putative drug targets.Graph representation learning (GRL) has incredible potential to efficiently predict the interactions from biomedical networks by modeling the robust representation for each node.> However, the current GRL-based methods learn the representation of nodes by aggregating the features of their neighbors with equal weights. Furthermore, they also fail to identify which features of higher-order neighbors are integrated into the representation of the central node. In this work, we propose a novel graph representation learning framework: a multi-order graph neural network based on reconstructed specific subgraphs (MGRS) for biomedical interaction prediction. In the MGRS, we apply the multi-order graph aggregation module (MOGA) to learn the wide-view representation by integrating the multi-hop neighbor features. Besides, we propose a subgraph selection module (SGSM) to reconstruct the specific subgraph with adaptive edge weights for each node. SGSM can clearly explore the dependency of the node representation on the neighbor features and learn the subgraph-based representation based on the reconstructed weighted subgraphs. Extensive experimental results on four public biomedical networks demonstrate that the MGRS performs better and is more robust than the latest baselines.

Compared with RGB images, hyperspectral images (HSIs) offer a distinct advantage in that they can record continuous spectral bands of light reflectance in each pixel, reflecting the physical and chemical characteristics of materials. This capability enables differentiation between objects that may have similar textures but different spectral characteristics. It is desirable to recover spectral information from RGB images to improve semantic segmentation accuracy. Additionally, semantic information can serve as a guide for spectral information recovery, thereby ensuring the quality of the recovered spectral information. The two tasks are mutually beneficial in this regard. In light of these considerations, we propose a multi-task framework that exploits the complementary relationship between spectral recovery and semantic segmentation tasks, comprising a complementary spectral-semantic attentive fusion model (CSSF) that enables the two tasks to mutually facilitate each other by fusing information from both branches. Specifically, the proposed CSSF incorporates a window-based spectral-semantic attentive fusion (WSSAF) module to incorporate recovered spectral information into the segmentation process effectively, and a pixel-shuffle-based fusion (PSF) module to provide semantic guidance for spectral recovery. To evaluate the effectiveness of our approach, we built the first flower hyperspectral image dataset (FHRS) with corresponding segmentation annotations and RGB images. By doing so, we have made the first attempt to explore the complementary relationship between semantic segmentation and spectral recovery. Experimental results on both the FHRS dataset and the publicly available LIB-HSI dataset demonstrate that our proposed method has the ability to enhance both tasks by utilizing their complementary relationship, indicating the generalization ability of our method.