I recently created a 78″x33″ stand-up banner (the kind you’d see at a trade show). I used one my photos in it and had to blow it up to fit in the 78″ tall requirement. In many cases, this can be a pretty scary proposition. In many cases making images larger than they start at can be a BAD thing. I hadn’t blown up an image that much in the past and had to do some research/experimentation on a few different tools/techniques to make sure it didn’t look like a blurry/pixelated mess on the very expensive banner.

I listed the three best approaches I found and brief instruction on how to do each. I preferred OnOne’s Photoshop plugin, Genuine Fractals, but any of these options will provide usable results when followed correctly.

Where to Start

It’s important to always start with as high quality image as you can. Ideally, you can use a RAW file or JPEG right out of your 6 or 7+ megapixel digital camera. You don’t want to grab a 800 pixel wide, been compressed multiple times image off of Google. The old addage is true here: Garbage in > Garbage out.

Also, when doing this, keep in mind that most folks are going to view a large print or poster from at least 3 or 4 feet away. As a result, they won’t need to be quite as sharp as an 8×10″ print.

The Options I Tried

I did some research and tried three different options. #1 and #2 were done directly in Photoshop. #3 was done with a Photoshop plugin.  Here’s how they work. Note that each one will make the file substantially larger (several hundred MB in some cases, so make sure your hard drive is ready to handle that). Also, in many cases I would apply a bit of sharpening to the photo after enlargement to crisp things up a bit (more on sharpening in a future post).

#1: Increasing 10% at a Time with Bicubic Smoother

Open the image in Photoshop and choose Image>Image Size. Uncheck the Resample Image checkbox and change the resolution to 200 and click OK.

Go to Image>Image Size again and re-check the Resample Image checkbox and change the option to Bicubic Smoother. Choose Percentage from one of the document size drop-downs and change the percentage to 110. Click okay.

The image will now grow by 10%. Repeat the Image>Image Size, percentage, 110 steps until your image is at the desired size.

#2: Increase all at Once with Bicubic Sharper

This tip is directly from Scott Kelby’s best selling book The Adobe Photoshop CS3 Book for Digital Photographers. He mentions in the book (and I’ll second it here) that this seems like the most non-traditional of the options. But, it seems to do the trick! The one downside to this option is that it produced the largest file size, which can get tricky when you start to consider Photoshop’s 2 GB file size limit.

Open the image in Photoshop and choose Image>Image Size. Change the settings in the box as shown below and click okay. It’ll process things for a while.

#3: Increase with OnOne’s Genuine Fractals Plugin

This is the only option of the 3 that requires an additional dip into the bank account (past the already pricey Photoshop). Make sure OnOne’s Genuine Fractals plugin for Photoshop is installed (it retails for around $160, unless you need to resize CMYK images and can be found here).

Open the image in Photoshop. Click onOne>Genuine Fractals>Scale Current Image…. The image will open in a new window, with new options. Set the desired resolution (around 200) and size and click okay. One benefit to Genuine Fractals is that it provides advanced previewing and sharpening options while in its resizing dialog box.

The Results

As I mentioned before, the results were all fairly decent, although they varied a bit. Of all, I preferred Genuine Fractals - it provided slightly sharper lines and less noise. I also listed the final file size for each.

Original File: 53 MB

#1: 10% at a Time: 934 MB

#2: Bicubic Sharper: 1530 MB

#3: Genuine Fractals: 928 MB