High-resolution enhanced cross-subspace fusion network for light field image superresolution

Light field (LF) images offer abundant spatial and angular information, therefore, the combination of which is beneficial in the performance of LF image superresolution (LF image SR). Currently, existing methods often decompose the 4D LF data into low-dimensional subspaces for individual feature extraction and fusion for LF image SR. However, the performance of these methods is restricted because of lacking effective correlations between subspaces and missing out on crucial complementary information for capturing rich texture details. To address this, we propose a cross-subspace fusion network for LF spatial SR (i.e., CSFNet). Specifically, we design the progressive cross-subspace fusion module (PCSFM), which can progressively establish cross-subspace correlations based on a cross-attention mechanism to comprehensively enrich LF information. Additionally, we propose a high-resolution adaptive enhancement group (HR-AEG), which preserves the texture and edge details in the high resolution feature domain by employing a multibranch enhancement method and an adaptive weight strategy. The experimental results demonstrate that our approach achieves highly competitive performance on multiple LF datasets compared to state-of-the-art (SOTA) methods.