The Hyperspectral Image (HSI) classification aims to assign each pixel to a land cover category. It is receiving increasing attention from both industry and academia. The main challenge lies in capturing reliable and informative spatial and spectral dependencies concealed in the HSI for each class. To address the challenge, we propose a Spatial-Spectral 1DSwin Transformer with Group-wise Feature Tokenization (SS1DSwin) for HSI classification. Specifically, we reveal local and hierarchical spatial-spectral relationships from two different perspectives. It mainly consists of a Group-wise Feature Tokenization Module (GFTM) and a 1DSwin Transformer with Cross-block Normalized Connection Module (TCNCM). For GFTM, we reorganize an image patch into overlapping cubes, and further generate group-wise token embeddings with Multi-head Self-Attention (MSA) to learn the local spatial-spectral relationship along the spatial dimension. For TCNCM, we adopt the shifted windowing strategy when acquiring the hierarchical spatial-spectral relationship along the spectral dimension with 1D Window based Multi-head Self-Attention (1DW-MSA) and 1D Shifted Window based Multi-head Self-Attention (1DSW-MSA), and leverage Cross-block Normalized Connection (CNC) to adaptively fuse the feature maps from different blocks. In SS1DSwin, we apply these two modules in order and predict the class label for each pixel. To test the effectiveness of the proposed method, extensive experiments are conducted on four HSI datasets, and the results indicate that SS1DSwin outperforms several current state-of-the-art methods. The source code of the proposed method is available at https://github.com/Minato252/SS1DSwin.

Automatic Photo Selection (APS) is a fundamental and important task for further photo cropping and photo enhancement. As the images in a photo series normally have subtle differences, it remains challenging to surface the best photos among highly similar photos. In this work, we propose a Recursive Multi-Relational Graph Convolutional Network (RMGCN) for APS. Specifically, we explore and devise inner-relation and inter-relation graphs to learn informative representations in hierarchical manner. 1) Patch-aware Intra Graph Module (PIGM) captures visual and spatial relations between different patches to characterize the representations in an image. 2) Context-aware Inter Graph Module (CIGM) explicitly exploits mutual comparative relation between different images in a photo series. These two graphs are recursively refined each other by reasoning the graph representations. Then, our model aggregates the output of CIGM with multi-scale local features via the proposed Cross-domain Fusing Gate (CFG) to boost the discriminative ability. Besides, we formulate four companion objectives as soft constraints to improve convergence rate during training. Extensive experiments are conducted on photo-triage dataset, and superior results are reported on different metrics when comparing to the state-of-the-art methods. We also perform rigorous ablations and analysis to validate our approach.