Friday, April 16, 2021

How to Upscale Photos to Super Resolution With Adobe Camera Raw

Super Resolution?

Super Resolution is fairly new, having been introduced in ACR 13.2. In a similar way to Raw Details (formerly Enhance Details) it sharpens edges, improves colour and reduces artifacts, but its biggest claim is to do all of this plus 2x the linear resolution (twice the width and height of the original). This is the equivalent of increasing your pixel count a whopping 4 times. It doesn’t just work on RAW files either, you can run this on JPEG and TIFF, meaning you can, in theory, now get a lot more mileage out of your photographs. Let’s look at how.

Potential Uses

If you’ve got an archive of images taken with older generation DSLR cameras, Super Resolution can open them up to new potential.

Or if you’re in a position where you’ve had to shoot from a distance (photographing wild animals for example) then that extra crop would be really useful in getting the image you really want.

Likewise, you might have images on an old camera, or even on your phone, that look great but are so few megapixels that they don’t lend well to being increased in size for print. Super Resolution can help with that.

How Does Super Resolution Work?

To understand how Super Resolution works, you need to know about Raw Details Enhancer as it uses a similar technique.

Each pixel your camera captures is only one of three colours: red, green or blue. Whichever colour it records, it’ll disregard the other two. Your software then goes through a process called demosaicing (or de-mosaicing, demosaicking or debayering) where it (using an algorithm) looks at neighbouring pixels to make a judgement about how much of that colour the light would contained (called interpolation).

In something like a sky or areas of similar colour, this is fairly straightforward, but when you get into busier parts of a photograph where there are lots of textures, patterns etc. the process can sometimes struggle, and that’s where you start to get issues like artifacts like noise or blotchiness. The better your camera sensor and processing units, the better the untangling of the finer details will eventually be, but when you reach its limit you might start to get moirĂ© patterns, soft edges and incorrect (or sharp changes in) colours.

Raw Details Enhancer takes these common issues into account and has been ‘trained’ on over a billion examples to make its interpretations more accurate. With Super Resolution, the algorithm is using the same ‘building block’ method to interpret neighbouring pixels and make the best decision as to what should be represented, but in addition it’s also building outwards, recreating those pixels in a way that not only enhances and preserves details and colours but also increases the size of the image.

How to Upscale Raw Photos in Adobe Camera Raw with Super Resolution

I'm using a free RAW photograph from Signature Edits to demonstrate.

Open your image
Open your image

Open Your Image

Open your image in Adobe Camera Raw. 

Image at 100%
Image at 100%

This is the image at 100%.

Enhance—Run Super Resolution

Right-click on the image in your filmstrip and click Enhance
Right-click on the image in your filmstrip and click Enhance

In the filmstrip (not on the large image preview) right-click and choose Enhance.

Enhance options
Enhance options

You’ll see the option to choose Super Resolution and notice that when you apply it, Enhance Details is also applied by default. A preview of the enhanced image is shown at 100%—if you click on that you’ll see the ‘before’ image for easy comparison.

There’s also an estimated completion time, this isn’t usually very long – around five minutes— but will vary depending on the size and complexity of your image and your computer’s processing power. Go and make yourself a cup of tea.

After enhancement at 100%
After enhancement at 100%

ACR creates a second image rather than adjusting your original, and this will appear in the filmstrip along side your original but with the addition of 'enhanced' in the title. This is the image after Super Resolution, at 100%. It's hard to see any difference looking at the image like this, so let's look at this and the original side by side.

Comparison

Enhanced (left) and original (right) images side by side
Enhanced (left) and original (right) images side by side

When they’re opened in PS you can see that the images viewed so that they look the same size are now actually different sizes – the original (right) is shown at 16.7% whereas the enhanced image is 8.33%.

Enhanced (left) zoomed to 100% and original (right) at 200%
Enhanced (left) zoomed to 100% and original (right) at 200%

If we look at the subject’s foot, which has very defined lines, you can see that at 100% the enhanced image is sharp and quite clear when compared to the equivalent original image which needs to be zoomed in to 200% to achieve the same size but lacks the clarity.

Trying a JPEG Image

Let's try Super Resolution on a JPEG image taken with a phone.

An image (JPEG) taken with a Samsung S8
An image (JPEG) taken with a Samsung S8

If you're using a JPEG (or any other format than RAW), you'll need to ‘open as Camera Raw’ to get it to open in Adobe Camera Raw. The image won't be able to use Enhance Details this time as that only works on RAW images.

Phone images side by side, enhanced (left) at 100% and original (right) at 200%
Phone images side by side, enhanced (left) at 100% and original (right) at 200%

Here are the images side by side, again with the enhanced image on the left at 100% and the original on the right at 200% to get the equivalent size. While the increase in size is obvious and beneficial to things like printing at a bigger size, you’ll see that zooming in to that extent looks posterized, there’s a definite lack of colours and definition and that’s due to the lesser quality of the phone’s camera sensor. This is really far into the distance though and at a regular size, even a large print, I don't think you'd notice this, unless you were printing it on the side of a building!

Super Resolution—The Verdict

Honestly, I was sceptical when I read about Super Resolution, as there’s usually always a trade-off to ‘upscaling’ something, but I really can’t see a downside to this. It isn’t perfect, though. It can’t create something you didn’t capture, so if you missed your focus it might sharpen the edges slightly but won’t make it a better quality image, just bigger. If the sensor you captured the photograph with wasn’t great to begin then it can’t add that detail, but there’s really nothing to lose by running the tool and seeing how it affects your image.

I also ran Super Resolution on a portrait to see how it dealt with details that matter, like eyes and skin, and really it was flawless. Occasionally I could see some noise or grain brought into the image – or more likely was there but has just been exaggerated by the process – but even that is negligible at the sizes we’re talking about. Give Super Resolution a try, I think you’ll be surprised and impressed at the results. 

More Adobe Camera Raw Tutorials

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