Answer:
In many image processing applications (Photoshop, The Gimp, etc.) there are filters that try to sharpen different kinds of blur (unfocused, subject motion, camera shake...) None of them work really well and it is difficult or impossible to fix perfectly.
Take a new picture: Use a tripod, use a faster shutter speed, use a more sensitive setting or film...
I have tried, with limited success, to place layer upon layer of image that was blurred due to camera shake and add the layers judiciously. The result was better but not great!