4 images are saved in tools/img folder, but demo_img.py is load 1 image.
furthermore, after show 1 image then stop terminal, so I reboot terminal.
What process did I miss? or could you give some tips for this problem?
There is a cv2.waitkey(0) command that stops the terminal and waits for your ESC key (to close the popup result windows). You can disable this line and/or use cv2.imwrite() to save the results to disk.