As the price of wide format photo printers like the ones offered by Epson, Canon, and HP continues to come down, more and more digital photo enthusiasts are adding them to their digital darkrooms. For less than $400, you can now print photo quality 11x14 images (actually, up to 13x19), saving money and time over sending these prints out to a photo lab.

The Problem
One of the biggest challenges to printing large images is getting a quality enlargement. Sure, you can print any image at 13x19, or even larger, but is it going to look good? Without the proper technique you're liable to end up with a pixely (that's a technical term for "gee that's one ugly digital picture!") mess that isn't going to look anything at all like the original photo. So, how do you take that digital image from your 4 or 5 MP camera and turn it into a large scale printed work of art?

The Solution
Luckily today's software makes it easier than ever to get a quality enlargement. If you use Photoshop or Photoshop Elements, you have a wealth of choices for enlarging your photos. Most of the plug-ins discussed here also work with other image editing programs that support the Photoshop plug-in standard. Examples of this are Microsoft Digital Image Pro and Jasc PaintShop Pro. In addition to the built in resizing feature, popular options include Extensis pxl SmartScale, LizardTech Genuine Fractals, and Shortcut PhotoZoom, along with Fred Miranda's Stair Interpolation Pro.

Using What Adobe Gave You
Photoshop and Photoshop Elements have always supported image resizing and have typically done a better job of it that most of the other applications available. In fact, unless you've wanted to print really big - and I'm talking poster size or larger - the image resize function in Photoshop will do the trick quite well. In order to resize your photo in these applications, simply select Image > Image Size. You'll see the dialog box in Figure 1.

Figure 1. The Image Size dialog in Photoshop (and Photoshop Elements) gives you control over resizing your masterpiece in several ways. The key feature here is to select the correct interpolation method.

There are two key options in this dialog that will control the quality of your enlargement (or delargement - yet another technical term. This one means reducing the image). The most important of these is the Resample Image option shown in Figure 2.

Figure 2. Choosing the correct option in the Resample Image list will improve the quality of your image resizing. When going larger, choose Bicubic Smoother. Reducing images works best with Bicubic Sharper.

The second option to look at is the resolution. If you're enlarging an image, it's safe to decrease the resolution. Why? Since larger photos (or any other artwork for that matter) tend to be viewed further back, lower resolution files give the same appearance of detail as the higher resolution version of the same file at a smaller size. For a 13x19 print, I'll typically lower the resolution to 240 dpi. The other advantage of lowering the resolution is that less physical resizing of the image is needed.

To resize your image with Photoshop, start out by selecting Image > Image Size. If you'll be enlarging the image, change the resolution to 240 dpi. Make sure the Resample Image checkbox is checked and select Bicubic Smoother from the dropdown list. Next, select the critical dimension for your image size - either height or width. Click OK and Photoshop will resize the image as requested. Need your image to be a specific size, like 11x14 or 16x20? The easiest way to accomplish this is using the Crop tool. Did you know that you can set specific measurements in the Crop tool? If I want a 16x20 print, I set those dimensions, shown in Figure 3, and then drag out the crop area as large as possible. This lets you easily define the area of the image to keep and gives you the exact dimensions you want for the final print.

Figure 3. By setting the exact dimensions for the print in the Crop tool, you can avoid odd print sizes (and the custom matting that comes with them).

The other approach to resizing is through the Print With Preview dialog shown in Figure 4.

Figure 4. You can resize your image in Photoshop's Print With Preview as well. This is fine for smaller enlargements, but for major resizing you'll have better results with the Image Size dialog.

Add-on Options
All of the following options claim to do a better job at enlarging images than Photoshop's own tools. Prices range from the very affordable Stair Interpolation Pro (SIPro) by Fred Miranda (www.fredmiranda.com, $19.90) and Shortcut PhotoZoom (www.shortcutpublishing.com), about $50) to the high end LizardTech Genuine Fractals (www.lizardtech.com, $159.00) and Extensis pxl SmartScale (www.extensis.com, $199.95).

SIPro, shown in Figure 5, works by using a popular method claimed by many to give better results. These folks claim that enlarging an image in 10% increments gives better results than resizing in one step. In earlier versions of Photoshop this was certainly true but the new bicubic smoother resize gives results just as good. If you use an older version of Photoshop, Photoshop Elements, or one of the compatible image editing programs, I highly recommend this plug-in as a cost effective way to resize your images.

Figure 5. Stair Interpolation Pro from Fred Miranda is an excellent choice for users of older versions of Photoshop or applications that support Photoshop plug-ins.

PhotoZoom is a new version of an old favorite, S-Spline. Sporting a new easier to use interface shown in Figure 6, PhotoZoom is an excellent option that works as well as, and in some cases better than, its more expensive competition.

Figure 6. PhotoZoom is a new version of S-Spline which some claim to be the best resizing method available.

Genuine Fractals and pxl SmartScale use their own proprietary resizing methods and claim that enlargements of up to 1600% with no visible loss of quality are possible. Of the two, I've had the best results with pxl SmartScale. The familiar Photoshop style interface, shown in Figure 7, and the being able to use regular TIFF files - Genuine Fractals requires you to convert to their own format - all fit into my workflow naturally. I haven't tested SmartScale to its limits, but prints up to 24x96 on the HP 130nr look great with no obvious image degradation. Both of these programs make it easy to set a specific print size which helps keep the image resizing optimized.

Figure 7. If you're used to Photoshop, you'll have no problem figuring out pxl SmartScale. It has the look and feel of an Adobe application. Simple adjustment options allow you to fine tune your enlargements.

For this story, I enlarged the same image using all of the applications mentioned earlier. The source image was a 5 MP JPEG enlarged to 16x20. pxl SmartScale gave me the best results but only by a small margin. Figure 8 shows the original image used and Figure 9 is a full size section of that image from each of the programs.

Figure 8. I started out with this image, a JPEG shot with a 5 MP Canon G5. The goal was to create a 16x20 print.

Figure 9. The same area shown at full size from each of the programs discussed here.

Conclusion
So, are these programs worth it? As usual, it depends. If you use Photoshop CS or Elements 3.0, I'd use the built in resizing function. If you regularly print poster size or larger, then I recommend pxl SmartScale. Users of older versions of Photoshop, PaintShop Pro and Digital Image Pro should be happy with Stair Interpolation Pro or PhotoZoom.

Editor's Comment: Let us know what you think! Please email the Editor to let us know your thoughts.

Jon Canfield is the co-author of Photo Finish: The Digital Photographer's Guide to Printing, Showing, and Selling Images, and the author of RAW Confidence. Jon also writes the Output Options column for eDigital Photo.