Adobe Finally Adds AI-based Noise Reduction!

Yesterday, Adobe delivered a much-requested feature in their photography products: Denoise, an AI-based noise reduction tool. Denoise is available in Lightroom, Lightroom Classic, Lightroom mobile, Adobe Camera Raw, and the Camera Raw filter in Photoshop.

It's well-known that Lightroom, while being one of the best programs of its type, had a notably crappy noise reduction tool. It was one of the biggest competitive differentiators for ON1 Photo RAW and DxO PhotoLab. And it was very common for Lightroom users to purchase external noise reduction software to address this fault. I myself bought Topaz Denoise AI, which I've been pretty happy with. Unfortunately, Adobe named their feature "Denoise" which is confusingly similar to the Topaz's Denoise AI. So for the rest of this post, I'll call the Topaz product "DAI".

Well, it seems like the calculus has now changed.

I've only just started playing with it, but my initial impression of the new Denoise feature in Lightroom Classic is very positive. Here's a before/after example. These images were screen-captured off Lightroom zoomed in to 100%, but you'll need to click on them to see them at full-size, which will make the noise levels really apparent.



I'm impressed not only with how noise-free the image is, but also there's almost no detail loss that I can detect. Take a good look at the lionfish's pectoral fin in the bottom-left of the image. There's actually more perceived detail, not less. Now, I'll admit that this isn't the best image to judge that on (not a lot of surface detail on a lionfish to begin with). But my initial tests of Denoise have been impressive.

In fact, so far I like it more than DAI. DAI sometimes produces strange, very unattractive artifacts in the details that I haven't yet seen with Denoise. Denoise just seems to produce results that are more accurate to the original image. And not having to leave Lightroom is an obvious workflow benefit.

There are a couple of areas where DAI is clearly better: The processing seems faster and its batch processing is much more flexible, allowing you to set the processing parameters individually for each image. 

But if the Denoise feature had been available in Lighroom at the time, it's unlikely I would have bought DAI. DAI's speed and batch processing advantages aren't worth the additional cost in my opinion. If I were regularly shooting huge numbers of high ISO images, I'm sure I'd feel differently. But for my needs, it's currently questionable whether I'll be renewing my Topaz license when it expires.

As I said, however, it's still too early to call for sure. I need to test and compare a lot more images. Sometimes you'll get an image that challenges the AI model and you get back really weird results. I'll post an update when I make a decision or when I have something new to report.

[Update 05/26/2023 – Okay, I've had the opportunity to use Denoise a lot more, including hundreds of photos from low-light, high-ISO sessions.

On images depicting more fine details, I think Denoise produces just a little bit softer images than DAI. Not a lot, but noticeable when you're really scrutinizing at 1:1 zoom. Part of that is due to Denoise's overly-aggressive default settings in my opinion. If I reduce the amount of noise reduction from the default setting, I can get more detail without appreciably increasing noise.

There's no longer any doubt in my mind, Denoise is considerably slower at processing than DAI. I haven't measured it, but anecdotally I'd say that it takes 2-5X the amount of time that DAI takes, depending on the photo. The processing time increases exponentially with image size. You'd expect it to take longer with bigger images of course, but that increase in time as image size increases is not linear. I can only imagine what it would be like if I had a 45MP+ camera! Even with the relatively modest file sizes my cameras produce, when I have dozens of images to process, it's truly a take-a-break-for-coffee type of operation. And as I noted above, the batch processing options are limited. I'm hoping Adobe fixes that last problem in a future release because that would be a fairly straightforward thing to do.

But the advantages of Denoise still exist: 1) Denoise doesn't seem to produce the distortion artifacts that DAI sometimes leaves behind. Its algorithm doesn't appear to have that flaw (or its training data has effectively eliminated it). And that's a huge advantage for obvious reasons. 2) Denoise is built-in and for non-batch processing, it has a more elegant workflow within Lightroom. And 3), Denoise is included at no additional cost to Lightroom. 

Those three advantages, plus the fact that it produces excellent results, makes DAI or other external noise reduction tools no longer worth the extra expense for me. If I were the type of photographer that regularly had hundreds of noisy photos to process, or if I had a super high-resolution camera, my conclusion would be different. But for my current needs, I don't see myself renewing when my current DAI update license expires. ]