A number of years ago, we were in New York City's Times Square, when we looked up and saw an enormous billboard with a photograph that was taken with a 3.2 megapixel camera. The picture was quite impressive--not just for its size, but for the quality--at least when viewed from more than a dozen stories below. The software used to enlarge that small 3.2 megapixel image to a Times Square billboard was Genuine Fractals ($160, 30-free trial with watermarks).
Contrary to popular misconceptions, a digital camera's number of megapixels is not a measure of the image quality it is capable of producing. Megapixels are a measure of the quantity of data, and nothing more. And where that counts the most is in how large a picture can be printed from your photo file. If you have a 13-megabyte file, you can usually get a decent 8"x10" print, which is plenty big for most of us. (Especially since most digital cameras now capture files that are much larger than that.) However, suppose you want to make a 24" x 32" poster. Or, perhaps, you want to print only a portion of your photo, say of your daughter without her ex-fiancé, or of just the kitten sitting on her lap, so you crop down to a small piece of the original picture. Either scenario could involve spreading the image data too thin, resulting in soft, undefined, pixelated prints.
You could use your imaging program or your printer driver to resize the file (a process called interpolation), but that simply duplicates the points of data without improving the image resolution. So, the result will usually be poor image quality, with lack of good sharp detail, as well as frequent "halos" (out-of-place color pixels).
When professional photographers run into these problems, they often turn to OnOne Software's Genuine Fractals. This Photoshop plug-in uses special fractal interpolation that can enlarge photo files as much as ten times the original, while maintaining image integrity, detail, and sharpness.
Genuine Fractals's straightforward, simple interface merely hints at its underlying power. Simply indicate what size you want your picture to be, and click Apply. If you have a specific print size in mind that is different from the aspect ratio of your original photo, you can have Genuine Fractals simultaneously enlarge and crop to the print size. This allows you to choose exactly what portions of your picture will be retained. The Batch option will resize all images in a single folder to the same dimensions. Or, if you want to make a really big print, you can use Genuine Fractals's Tiling feature, which breaks an image into sections, each of which can be printed out on standard-sized paper then put together in a mosaic. Other options include sharpening the image--based on luminosity, which in some cases can be a better engine than typical sharpeners--adding simulated film grain, and applying texture.
The Professional Edition of Genuine Fractals ($300) adds integration with Aperture and Lightroom, plus a Gallery Wrap feature which is very useful if you are printing out on canvas and want the picture to wrap around the edges of the stretched canvas.
Genuine Fractals is an excellent tool with a single purpose: to make large prints look good. If you plan to do large printouts, or if you tend to crop your image files down to small details and still want to make good-looking prints, then Genuine Fractals may prove a valuable program to add to your arsenal.