Note: pricing for this product is in US$.

Enlarging images is something every designer and illustrator has to do on a regular basis. From incorporating low-resolution photos or video stills into your page designs to using a high-res image on an even larger poster, there is a whole range of circumstances where you need to use an image larger than its original size without sacrificing quality. Photoshop has the basic Image Size menu item, but if you want to boost it by more than about five per cent, though, you’ll need to buy a plug-in such as Alien Skin’s Blow Up 2.

Blow Up works by expanding the size of an image and ‘intelligently’ filling in the missing details through judicious use of sharpening and the addition of fake grain. The upgrade includes better overall output, faster performance, batch processing and a series of presets so you can scale images up for paper sizes and types.

Enlargement tools are popular with designers and illustrators, so Blow Up has a lot of competition. Until Blow Up 2 arrived, the clear leader was OnOne Software’s Genuine Fractals Print Pro 5 which, at $299.95, is similarly priced to Blow Up’s $249.

Blow Up 2’s output is a definite improvement over the first release — and hugely better than Photoshop’s Image Size. Across many types of image, the upgrade allows you to push images larger than before — whether you want to enlarge images with softer edges by a lot or boost crisper photos with strong, hard lines by a smaller amount. Blow Up 2’s output matched that of Genuine Fractals as we resized images — and often we couldn’t tell them apart.

Where Blow Up pulls ahead of OnOne’s tool is in its speed and functionality. On our test 8-core Mac Pro with 4GB RAM, we found Blow Up 2 to be almost twice as fast as Genuine Fractals — for example taking 14.5 seconds to expand a low-resolution image to ten times its original size, compared to 27 seconds using Genuine Fractals.

Paper presets

Blow Up also includes presets, so you can be sure that an enlarged image can be used at A4 or A3. Or rather, you can if you create those presets yourself, as Alien Skin’s lengthy list contains only American paper sizes. Creating UK-friendly presets is straightforward and, Euro-phobia aside, the presets system is a very useful addition.

You can see how your image will be cropped by the aspect ratio of your target output — whether this is a paper size or the dimensions of a picture box in QuarkXPress or InDesign — with the Smart Crop function focusing on the region with the most detail.

The Crop to Size tool is an excellent addition, enabling you to select an area of the image, which will be enlarged to your selected output size. You need to deselect the crop before output, though, so that you have some bleed.

Equally useful for the designer in a hurry is the batch-processing system (below), which quickly resizes all of the images in a folder. This is unique to Blow Up and a massive timesaver if you’re up-sizing multiple images.

If, on the other hand, you want to fine tune how a single image is resized, there are four slider controls over how your images are uploaded: Sharpen Edges, Add Grain, Preserve Natural Texture, and Remove Compression Artifacts. These are a sliding scale of tools that you use depending on how bad your original image is – so a small increase in size of a reasonable-quality image may only require a small amount of Sharpen Edges, while a poorly-compressed Web image will require lots of all these tools.

Other notable additions include support for 32-bit HDR images and, according to Alien Skin, faster processing on 64-bit operating systems when used with the next version of Photoshop (which is expected by the end of the year).