Noise reduction introducing "hot pixels"

[mike.cargal]

I’ve seen this on a number of images now. Sharpening on images with fairly bad noise introduces hot (bright white) pixels.

Steps to reproduce issue:

1. Lightroom classic (File menu… Plug-in Extras… process with Photo AI)
2. Removing Noise and Sharpen are both auto selected.
3. Dark areas have bright white speckles introduced.
4. If I turn of sharpening, speckles go away (mostly, but not entirely)
   
   
   
   . (but, of course, I’d like the actual sharpening.

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Topaz Photo AI [v2.3.0] on [Windows/Mac]

[mike.cargal]

Hmmm… it’s not obvious in the post itself, but you can see it if you load the pics and zoom in. Looks like something is manipulating my upload. Here’s a smaller crop with the noise.

[jeff.topazlabs (jeff.topazlabs@gmail.com)]

It looks like this issue happens primarily with areas that are low frequency/low light so there is very little detail in those parts of the image. Processing those areas is causing this artifact as the model does not have enough information to work with.

A workaround would be using a lower Strength for Raw Remove Noise so it does not over-process the low detail areas and cause this artifact.

I will also inform the developers of this issue to be addressed in the training models in the future

[mike.cargal]

Thanks for reply…

Lowering strength of noise reduction using “RAW Normal” didn’t do much until I was down to 1 and still did not disappear. (but, of course plenty of color noise)

Playing around a bit, using “RAW Strong” and bumping up the “Remove Large Grain” (to about 10) gets rid of almost all of them

Thanks for pointing me in a direction to deal with it. Obviously, would be nice for them not to pop up to begin with though.

[jeff.topazlabs (jeff.topazlabs@gmail.com)]

Of course, glad we go it a little better but obviously have some more work to do. We will continue to make improvements to our training models so please just be patient with us and keep an eye out for a new update coming in the near future