Fig. 1. Comparison of feature point detection methods. (a) Infrared images; (b) visible images

Fig. 2. Schematic of feature point main direction allocation

Fig. 3. Flow chart of descriptors for multiscale histogram of oriented gradients

Fig. 4. Local effects of precise matching methods for process optimization

Fig. 5. Experimental results. (a)‒(f) Partial experimental results for dataset 1; (g)‒(l) partial experimental results for dataset 2

Fig. 6. Fusion of grayscale images. (a)‒(f) Partial fusion grayscale image of dataset 1; (g)‒(l) partial fusion grayscale image of dataset 2

Fig. 7. Alignment performance evaluation results for ten algorithms. (a) Accuracy matching points evaluation results on dataset 1; (b) accuracy matching points evaluation results on dataset 2; (c) precision evaluation results on dataset 1; (d) precision evaluation results on dataset 2