Computer, enhance
A web-based photo enhancer called Mejorar Imagen is the best I've come across for quickly improving the quality of blurry, pixelated photos. Just select an enlargement multiple, drag your photo into the window, and wait for a minute or two. The results aren't always perfect, but they are often excellent. I used it on a purposely downscaled photo from the Library of Congress to show you the results. — MF