Windows: A Sharper Scaling is a single-purpose app that increases the size of an image while preserving an impressive amount of detail. Compared to conventional image upscaling methods, A Sharper Scaling almost pulls off a magic trick.
Of course, it's impossible to zoom into an image infinitely like they do on television shows ("enhance!"), but A Sharper Scaling manages to do some guesswork and smooths out the rough pixellated edges without just blurring the image.
Normally, if you upscale an image in Photoshop or an equivalent program, it basically just increases the size of the pixels by repeating them and then softens the blocky results in a process called bicubic interpolation. But A Sharper Scaling's technology does something else behind the scenes — calculations that I certainly don't understand — and produces marginally sharper results. It works particularly well with graphic images:
The advantage when scaling photographs is more subtle, but still quite good if you're a stickler for details (zoom into the image at the top of this post for an example). The software, developed by Steffen Gerlach, is free and available under a Creative Common licence. The interface is simple, clear and effective, as it only does one thing. Visit their site to see more examples and to try it out for yourself.