Can software make fuzzy pictures sharper?
Not really. But the "sharpen edges" or "edge enhancement" function will make some
images look sharper.
Result of 15% diagonal sharpening in Graphic Converter. This works best on 32-bit (millions of colors) images that have
lots of natural sharp edges.
How to do it:
Graphic Converter (Macintosh): Effect --> Sharpen Edges...
Paint Shop Pro (Windows): Image --> Normal Filters --> Sharpen
How does it work?
The computer does not really sharpen the image, it just enhances the edges
by lightening the light side of edges and darkening the dark side of edges.
Close up (X4 zoom) of upper left corner of original image
Close up of the sharpened image. Notice that the
blocks (pixels) are the same size, but their color is lightened or darkened to enhance the edges,
which makes it look sharper when viewed from a distance.