Image Resizing, Upscaling, and Super Resolution

Photo by Corey Decker, from Instagram, used with permission.

Earlier this year, we launched a new image resizing capability in our SDK, and in the months since then we’ve received lots of great feedback.

In this post, I’ll share a bit of that feedback and explain what this new capability can do for your business!

So, what’s new?

Basically, we’ve added the ability to resize images within the Perfectly Clear SDK imaging pipeline. When people talk about digital photo size, they can be referring to one of two different things: image size (measured in pixels) or print size (measured in inches or centimeters).

Image resizing involves something called “interpolation”; that’s when software enlarges an image by comparing adjacent pixels in the image and then creates a “best guess” at what pixels to add in between to create the new scaled-up version. For example, to enlarge a 1200 x 1000 pixel image to 2400 x 2000, would require the software to create four times as many pixels as found in the original image. The issue is that all interpolation algorithms are not created equal. With this latest improvement to our SDK, scaling is now handled brilliantly when scaling images up, or down.

Why is it needed?

You may be wondering; with camera technology getting better and better, why does this even matter? Isn’t a 12 megapixel point-and-shoot or smartphone camera good enough these days? Yes, but if the image is uploaded to social media or emailed around, that can often dramatically compress the image. Even worse, printing an image directly from a platform like Instagram, for example, can lead to undesired, and low-quality results. That is exactly the problem we are solving. Our updated resizing algorithms allow you to print low-resolution images at a much higher quality.

Why it’s so important?

When a digital photo is printed, the pixels in the photo are reproduced on paper. The more pixels in the photos, the more of these will be printed on each inch of the print – this is PIXELS PER INCH or PPI. Most printing services have a minimum PPI requirement of about 180; so if you want to make an 8×10 inch print, you need an image that is 1440 by 1800 pixels (8 inches times 180 pixels per inch = 1440 pixels). For best print quality, many recommend 240 PPI, which would be 1920 x 2400 pixels. Images on Instagram are 1080 wide, so many print services won’t even allow you to order an 8×10 print from these images.

Adding our high-quality image resizing process to your production workflow can open up new printing products to your customers, and result in happier customers!

One Example in Detail

The example above, we’re looking at here is a fantastic photo from Corey Decker that we found on Instagram. It’s a very high-quality image, so it makes a perfect subject for this resizing example. The original image is at the top of this post, and we’ve zoomed in on a detail and shown this resized in two ways;

The left side is using a very simple resizing – this image quality would be what you might expect if no resizing were done at all and the image was printed quite large – roughly 11×14 inches. The image on the right shows our resizing. Both are shown zoomed in quite a bit – this is required in order to show the detail that would be evident on a print of this size.

It goes without saying, if you were to order a print from Corey, he’d print his original image – not the one uploaded to Instagram. But our print customers from around the world may receive images as small as 640 x 800 pixels every day!

Our new resizing process allows larger and better prints from these smaller images, with very little additional effort or cost. Enjoy!

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