How to recover deleted photos from Android's internal memory
If fortunately, you have backed up your photographs in Google Photo, then you can simply open it, go to the "Trash" and choose the photos that you've backed up and tap on the "Restore" option.

Note: 

1.This method is only useful for the data that have been deleted within 60 days.

2.Be sure that the option "Backup &amp;sync" in the "Settings" of Google Photo has been turned on.