1. Click the Sub-Image button or press P on the keyboard to enter the sub-img settings, where you can set the sub-image size and save location.
2. Select a region and click the left mouse button to save it automatically.
3. The second time you click sub-img, the previous settings will be used by default. To reset them, click Configure Paths in the menu bar.
4. Both the sub-image and its corresponding annotation are saved correctly.
