RTDS: A Robust two-stage tongue diagnosis system with U-Net++ segmentation and swin-hybrid classification
摘要
Tongue diagnosis is important in Traditional Chinese Medicine (TCM), but routine inspection remains subjective and inconsistent across observers. Real outpatient images add background clutter, illumination variation, and label ambiguity. We propose RTDS, a two-stage framework for noisy clinical data: Stage 1 uses U-Net++ for tongue ROI extraction, and Stage 2 uses a ResNet-34 + Swin hybrid classifier with Focal Loss for imbalance- and ambiguity-aware learning. On 2,100 real outpatient images, RTDS achieves 75.76% Top-1 accuracy for seven-class tongue appearance classification and 91.30% accuracy after mapping to four diagnostic states, outperforming strong baselines under the same protocol. Grad-CAM results show attention concentrated on clinically relevant tongue body/coating regions, supporting practical interpretability.