Fig. 1. NIR-II imaging system. (a) Schematic diagram of NIR-II fluorescence imaging system; (b) comparison of pixel size between NIR-II detector and visible light camera, and its impact on imaging quality, enlarged area is imaging effect of fine blood vessels under resolution constraint; (c) schematic diagram of Real-ESRGAN network architecture

Fig. 2. Performance comparison of different super-resolution methods in NIR-II mouse blood vascular imaging. (a) Evaluation process of model performance; (b) comparison of reconstruction results for mouse back blood vessels by different methods, lower areas are magnified details; (c) LPIPS and PIQE of different methods based on 160 test images

Fig. 3. Application of Real-ESRGAN in NIR-Ⅱc band imaging. (a) Original NIR-Ⅱc images and processing workflow in different scenarios; (b) high-resolution reconstruction results processed by different methods, lower area is magnified details, scale bar is 5 mm; (c) intensity distributions of multiple blood vessels

Fig. 4. Performance of Real-ESRGAN in clinical application of diabetic foot. (a) Clinical data acquisition process; (b) high-resolution foot blood vascular images processed by different methods, right area shows magnified details; (c) intensity distribution of multiple blood vessels