The rather inelegant adage "garbage in, garbage out" is not always true. LizardTech's Genuine Fractals PrintPro 3.0 and Extensis's new pxl SmartScale -- plug-ins for Adobe Photoshop -- rework this old equation. Both let you take images previously considered too small for anything other than the Web and enlarge them with enough clarity and image integrity for print output. (The plug-ins are compatible with Adobe Photoshop 6.01 and higher.) You'll get astoundingly good results -- either product can scale an image to as much as, and in some cases more than, 16 times its original size. But while Genuine Fractals is powerful, its somewhat quirky workflow is less intuitive than pxl SmartScale's straightforward, get-it-done interface.

Genuine Fractals PrintPro 3.0

Genuine Fractals PrintPro 3.0's image-enhancing technology is based on LizardTech's MrSID application, which is also the basis for satellite-image enhancement and other politico-spy mumbo jumbo. Suffice it to say that you must save your documents as proprietary STN files. Then you'll choose between lossless or visual lossless encoding. Lossless encoding makes no changes to your image, leaving it untouched. Visual lossless encoding creates a file that is slightly smaller; although there is no discernible visual difference from the original, some data is removed. A good rule of thumb is to keep as much data in your image as possible. So unless you're running out of space on your hard drive, our advice is to use the lossless option.

The STN file acts as a source document for your image. Opening it in Photoshop brings up the Genuine Fractals interface, a curvilinear workspace that shows pertinent size, color-space, scaling, preview, and cropping options. The process is relatively self-explanatory.

Output quality is phenomenal. We turned a 703K image file into a 176MB one with no major visual artifacts or loss of clarity. Using either of these programs, you won't be able to take a tiny picture from the Web and blow it up to be a good-looking poster, but the quality is definitely good enough for professional flyers or newsletters.

Genuine Fractals handles CMYK and CIE-Lab color spaces, as well RGB, grayscale, and bitmap images. The lower-end versions of the software -- Genunine Fractals 3.0 LE ($50) and Genuine Fractals 3.0 ($159) -- are limited to RGB and gray scale, and the LE version won't let you scale beyond 64MB. The PrintPro version can scale beyond the 1,600 percent that pxl SmartScale peaks at, but you'll need a lot of RAM to do it.

If you often need to make global changes to images, be aware that the plug-in itself doesn't actually include a batch command; instead, it relies on the batch facility found in Photoshop. You create an action that sets your rescaling parameters and invoke it from Photoshop. This strikes us more as a workaround than an inclusive feature.

Pxl SmartScale

Easy to use and understand, pxl SmartScale is good at what it does. It, too, uses proprietary algorithms to work its magic, but pxl SmartScale borrows its interface from Photoshop. This familiar environment helps speed your workflow. (Sadly, there's no batch-processing capability to expedite global changes to multiple images.) With no strange file format to deal with and a real-time preview, you enhance images on-the-fly by adjusting the following settings: Overall Sharpness, Edge Contrast, Edge Detail, and something called Extreme Edges. (Think of Extreme Edges as a pumped-up Unsharp Mask.)

Adjustments are preset, however, and we would have preferred slider controls. Still, you can experiment, and in most cases you can find an effective image quality that will sustain an exceedingly large scale. We took the same 703K we'd used earlier and again turned it into a 176MB file, and we got excellent results.

Macworld's Buying Advice

These two plug-ins prove that a small image can be surprisingly clear when it's scaled to a relatively gigantic size. Fans of Genuine Fractals will not be disappointed with the PrintPro 3.0 version, but if you're looking for an efficient and intuitive way to get great results, pxl SmartScale is for you.