EAAI Journal 2026 Journal Article
A dual branch fusion network for self-supervised sonar image despeckling
- Yunhong Duan
- Shubin Zhang
- Yaoguang Wei
- Dong An
- Jincun Liu
- Yan Meng
Sonar image despeckling is necessary for downstream scene understanding tasks by providing high signal-to-noise ratio despeckled images. Current despeckling methods often require clean images for supervision, however, clean sonar images are inaccessible. Therefore, we propose a self-supervised method based on blind spot network, only using single noisy image for training. In addition, due to the strong spatial correlation of speckle, speckle noise blends with the fine textures of image, making it challenging to keep fine textures while removing speckles. To address this issue, we design a novel dual branch fusion blind spot network that despeckles flat and textual areas separately to maintain fine textures while removing speckles. During training, the flat area is smoothed by the flat branch utilizing a large blind spot excluding more correlated noisy pixels. In contrast, the details in the textual area are recovered by the texture branch employing a small blind spot which incorporates more adjacent pixels for prediction. The flat and texture branches are supervised by a novel spatially adaptive loss to enhance feature extraction. In addition, a variable blind spot is utilized to further balance the capabilities of speckle suppression and detail preservation. Extensive experiments on the synthetic, sidescan, and forward-looking sonar datasets demonstrate that our method achieves superior performances in balancing the speckle suppression and detail preservation compared to state-of-the-art methods, producing high-quality despeckled images while removing visible speckles. The proposed method may improve underwater perception by providing high quality acoustic images, hence advancing ocean exploration.