With today’s camera’s packing more megapixels and bigger sensors, you’ll more often find yourself scaling a photo down than you will scaling one up. But there are times when enlarging a photo can really come in handy. Unfortunately, increasing the size of a picture usually means a significant loss of quality. There are a few ways you can try to tackle this problem, and we’ll go over two of the best here.
Something to Keep in Mind
When you increase the size of an image, you’re asking your computer to add information. Put succinctly, you’re telling it to guess at what a larger image would look like. That means you’re never going to get a perfect recreation of your photo at a larger size. Because it’s a matter of software, some apps will be better at it than others. But they all have to make guesses.
The amount of guessing your computer has to do varies with how much you want to increase the size of your image. The more you increase it, the more likely you are to see a degradation of image quality. Understanding that up front is important. (If you’ve used upscaling with home entertainment equipment, you’ll have a good idea of what I mean.)
Resampling with a 10% Increase
This is a commonly recommended method for seeing just how much up-scaling you can get away with. It works best if you’re not trying to scale your image to a specific size, but instead want to make it as large as possible without making it look too bad. I’ll use this image as an example:
It’s currently 250 pixels wide, and if you lean toward your monitor and squint, you can probably make out the text. But everything is pretty smooth; the image looks nice. To make it larger, we’re going to take advantage of resampling, which is the “guessing” I was telling you about earlier. Here’s what happens when we scale it up to 650 pixels:
As you can see, the text is just barely still readable, but the entire image is of a noticeably lower quality. It’s easy to imagine some details in a different image becoming indistinguishable. Instead of making the jump all the way to 650, we’ll just add 10% to the original image size. Here’s the original image scaled to 275 pixels wide:
It still looks pretty clear. Let’s bump it up to 325.
Still not too bad. Why not try a bigger jump and go up to 450?
Now we’re starting to see some graininess. You’re probably starting to get it by now: making small steps up helps you keep the quality of the image as high as possible while making it big enough to emphasize whatever it is that you’re trying to point out in the image.
If you’re going to use this method, it’s important to make sure that resampling is enabled in your photo-editing app. I use Pixelmator, and here’s what it looks like in the Image Size menu:
Other apps, like GIMP and Photoshop, will offer a similar option. You might even be able to choose the interpolation algorithm (the computer’s guessing method) for the scaling. When you’re scaling up, the bicubic smoother option is a good one.
Using a Dedicated App or Service
Because so many people find themselves in need of larger photos, there are actually a number of apps designed specifically to do this for you. A Sharper Scaling, for example, is a free Windows app that promises better upscaling than Photoshop. The results posted on their website are quite impressive. It does one thing and one thing only, but it’s free, so definitely worth downloading.
There doesn’t seem to be a good free equivalent available for the Mac, but that doesn’t mean you don’t have options. Waifu2x, however, provides a solid online option. Waifu has shown very impressive results with anime images, but results can be slightly unpredictable with photos. Still, when it works, it really works well. There are plenty of others out there, and you may see different results with the same photo.
Unfortunately, you may just have to try a few of them to see which works best for your specific image. Here’s an example of what Waifu can do for our image. I uploaded a 250-pixel-wide version and asked it to scale it to 500 pixels wide:
And here’s the Pixelmatored version:
Even without zooming in, you can probably see that the image from Waifu is significantly clearer. The site’s use of deep convolutional neural networks makes it very adept in the “guessing” that I mentioned earlier, and the result is significantly clearer upscaled photos. If Waifu isn’t working well for you, though, you can try the Online Image Enlarger, Simple Image Resizer, or Rsizr.
Your Best Upscaling Tips
These two methods of increasing image size are probably your best bets when you don’t want to lose quality. Neither is perfect, but because of the constraints of technology, they’re about the best we can do. Fortunately, most phones and cameras now take very high-resolution photos, so you shouldn’t have to deal with this too often. Just remember to always work from the largest original image you can.
How do you upscale images? Do you use these methods or something else entirely? Share your best tips in the comments below!
Image Credit: fractal-an via Shutterstock.com