HyperCASR: Spectral-Spatial Open-Set Recognition With Category-Aware Semantic Reconstruction for Hyperspectral Imagery.

Open-set recognition (OSR) in hyperspectral imagery (HSI) focuses on accurately classifying known classes while effectively rejecting unknown negative samples. Most existing reconstruction-based approaches are susceptible to noise interference in the input images, and known classes can easily lead to inter-class confusion during the reconstruction process. Moreover, effectively utilizing the abundant spectral-spatial information in HSI within an open-set context presents significant challenges. To address these issues, we propose HyperCASR, an innovative framework for HSI OSR that integrates a grouped spectral-spatial retentive transformer (GSSRT) and a class-aware semantic reconstruction (CASR) module. This method begins by designing the GSSRT to extract features from HSI, enhancing the extraction capability of spatial-spectral information by introducing a grouped pixel embedding (GPE) module and a novel spatial retentive attention (SRA) mechanism. Subsequently, an independent autoencoder (AE) is assigned to each known class to reconstruct semantic features, which helps to mitigate noise interference and inter-class confusion. Additionally, by minimizing reconstruction errors to estimate class affiliation, the framework effectively identifies unknown classes. Experimental results across three benchmark datasets indicate that the HyperCASR framework significantly enhances classification performance for both known and unknown classes when compared to existing state-of-the-art methods. The code is available at https://github.com/B-Xi/TIP_2025_HyperCASR.