Fig. 1. A schematic representation of the proposed algorithm

Fig. 2. Phantom and experimental setting used in this study

Fig. 3. Representative experimental data used for network training. (a) Typical examples of true images; (b) typical examples of input images of the Unet network

Fig. 4. Loss curves for training and validation datasets during the training stage. (a) Loss curves for single target dataset; (b) loss curves for two targets dataset

Fig. 5. Reconstructed images by different algorithms at different depths, where the depth of the fluorescent target in (a)--(e) increases from 10 mm to 50 mm with the step size of 10 mm

Fig. 6. Profiles of quantum yield of single target reconstructed image along horizontal direction of the center of the fluorescence target, where the depth of the fluorescent target in (a)--(e) increases from 10 mm to 50 mm with the step size of 10 mm

Fig. 7. Quantitative results for different algorithms. (a) MSE; (b) PSNR; (c) SSIM

Fig. 8. Statistic results for different algorithms. (a) MSE; (b) PSNR; (c) SSIM

Fig. 9. Reconstructed images with different algorithms in case of two targets, where the edge-to-edge distance of two fluorescent targets in (a)--(f) decreases from 5 mm to 0 mm with step size of 1 mm

Fig. 10. Profiles of quantum yield of multiple targets reconstructed image along horizontal direction of the center of the fluorescence target, where the edge-to-edge distance of two fluorescent targets in (a)--(f) decreases from 5 mm to 0 mm with the step size of 1 mm

Fig. 11. Reconstructed images of multiple targets by our algorithm at varied depths

Fig. 12. Reconstructed images of single target at different contrasts. (a) Contrast is 4∶1; (b) contrast is 3.5∶1; (c) contrast is 3∶1; (d) contrast is 2.5∶1; (e) contrast is 2∶1

Fig. 13. Reconstructed images of two targets using the model trained on a single target datasets. (a) Edge-to-edge distance is 5 mm; (b) edge-to-edge distance is 4 mm; (c) edge-to-edge distance is 3 mm; (d) edge-to-edge distance is 2 mm; (e) edge-to-edge distance is 1 mm; (f) edge-to-edge distance is 0 mm