Fig. 1. Structure of stereo light microscope. (a) Greenough microscope; (b) common main objective microscope

Fig. 2. Depth of field and resolution at different apertures. (a) Depth of field at different apertures; (b) maximum resolution distance at different apertures

Fig. 3. Schematic of asymmetric aperture modification

Fig. 4. Flow diagram of the proposed algorithm

Fig. 5. Error of focus area. (a) Error of initial registration; (b) error after ECC optimization

Fig. 6. Flow diagram of the image fusion algorithm

Fig. 7. Selection mode of sample pair

Fig. 8. Diagram of microscope system. (a) SZX7 microscope system; (b) module of aperture diaphragm

Fig. 9. Captured image and partial magnification. (a) High resolution image and partial magnification; (b) large depth of field image and partial magnification

Fig. 10. Captured source images. (a) (c) High resolution images; (b) (d) large depth of field images

Fig. 11. Comparison of image fusion results. (a) High-resolution source images; (b) large depth-of-field source images; (c) Laplacian algorithm; (d) edge filtering algorithm; (e) guided filtering weighted detection; (f) CNN; (g) proposed algorithm

Fig. 12. Image fusion evaluation results. (a) Changes of average gradient; (b) changes of edge intensity