TR_Unet: a residual-enhanced U-Net for robust tongue image segmentation in complex conditions
摘要
Tongue images play an essential role in Traditional Chinese Medicine (TCM) diagnosis, and accurate tongue segmentation is vital for intelligent tongue analysis. With the growing application of artificial intelligence in tongue diagnosis, robust segmentation is increasingly important for reliable feature extraction and automated syndrome assessment. However, complex backgrounds, large variations in appearance, and small tongue proportions make segmentation highly challenging. This study enhances the U-Net framework by introducing an EC module featuring a residual structure, which aids in stabilising deep feature learning and mitigating the issue of gradient vanishing. We further introduce a Rectangular Self-Calibration Module (RCM) to strengthen foreground extraction and employ an edge-weighted composite loss to improve boundary precision. Experiments across diverse tongue types show that our model achieves more accurate and robust performance than other state-of-the-art methods. Overall, the proposed approach improves IoU by 3.2% over standard U-Net and provides a stronger foundation for practical AI-driven tongue diagnosis systems.