EAAI Journal 2026 Journal Article
Microscopic image segmentation of harmful algal blooms using pyramid fusion enhancement and dual-branch network
- Gengkun Wu
- Chao Cui
- Yining Fan
- Yubing Li
- Xin Tian
Monitoring harmful algal blooms (HABs) is important for marine ecosystem protection. However, HABs microscopic images often suffer from wavelength-selective color attenuation, low contrast, and scattering blur, which severely impair segmentation. To address these degradations, we propose a task-oriented enhancement-and-segmentation framework for HABs microscopy. In the enhancement stage, cyclic color channel compensation and particle swarm color balancing restore inter-channel consistency, while adaptive pyramid fusion selectively recovers fragile algal structures without amplifying background impurities. For segmentation, we propose the Transformer Convolution Fusion Network (TCoF), a dual-branch architecture combining Transformer-based global context and CNN-based boundary details. Its core novelty lies in the proposed Multi-scale Feature Complementarity Module (MFCM), which uses CNN-derived boundary priors to explicitly guide Transformer feature aggregation across scales, thereby reducing attention drift in turbid backgrounds. In addition, the detail-aware spatial pyramid pooling module (DASPP) compensates for the contour-smoothing bias of standard ASPP and improves the delineation of thin algal structures. Experiments on the AICO Lab dataset show that the proposed framework achieves state-of-the-art performance with an mIoU of 91. 52%.