Perfect Resize uses fractal-based interpolation to enlarge digital images without losing sharpness or detail.
The program opens with a thumbnail browser which allows you to select your target image (there's full support for layered Photoshop files).
Click Resize > Edit a Copy > OK and your image appears in the editing window. Crop the picture if necessary, then enter its new dimensions (pixels or a percentage), and click "100" to view it full-size.
We found the program generally produced good results - no pixellation, a sort-of "oil painting" effect on very large magnifications but nothing too serious - and if you're happy then you can just click "Save & Close" to continue.
If your resized picture doesn't look so good, there are various settings which may be able to help: Image Type, Resize Method, Texture, Threshold, Smoothness, Sharpening, Film Grain, and more. Tweak any of these and the preview window updates within a few seconds to show you the results.
The program also supports some unusual extras. Turning on "Tiling", for example, allows you to divide an enlarged image into smaller pieces that can be printed on a smaller printer. And "Gallery Wrap" displays custom margins around the image, very useful to ensure it's framed correctly when you're printing on canvas.
This is the standard edition, and only runs stand-alone. Perfect Resize Premium ($149.95) also works as a Photoshop plug-in, integrates with Lightroom, Photoshop Elements and Apple Aperture, opens RAW files and can batch process multiple images.
Please note, the download link takes you to a registration page where you must first enter your name, address and country. This gets you a 30-day trial which is otherwise unrestricted, and allows you to resize and save as many images as you like.
Its results vary depending on your source material, but Perfect Resize generally produced good quality images for us, even at high magnifications (6x). If you regularly resize images by a significant amount, and quality is vital, give it a try.