[Leica] comparison of 4 noise reduction programs

[Howard L Ritter Jr]

Don, the stunning superiority of the LR Enhance image in terms of sharpness of the subject’s hair, face, sweater, and nametag (or alternatively, the comparative lousiness of the other results) beggars belief. I have to wonder whether something didn’t go wrong. Among the three, only in the TopazAI is her face in focus, while it’s not even close in the other two. Something other than noise level is involved in the differences in resolution and focus. I can’t imagine there being any way that the level of detail in the LR image could have been recovered from a primary image as out of focus as the other two would suggest, even with a dedicated sharpening program, let alone merely a noise-reduction program.

For example, in the LR image, look at the leftmost strand of hair, which goes from highlighted to darkly silhouetted against the background figure as it sweeps upwards. In the other images, there is not even the merest suggestion of this latter part, only the uniform blur of the background. 

Look at her nametag and ribbon. In three images, including Topaz AI, the printing isn’t even recognizable as such. But in the LR image, her name is not only recognizable, not only easily readable, but actually sharp, even down to the presence of the demarcation that shows her last name is ‘Martin’ and not ‘Martln’. And it’s puzzling that the TopazAI image, which has the face in so much better focus than the Topaz DeNoise and the DxO, doesn’t do any better on the nametag.

How can this be? Did one program perform magic, or did the other three actually degrade details?

Can you post the unprocessed image for comparison? That would be extremely interesting.

—howard

> On Apr 19, 2023, at 6:50 AM, Don Dory via LUG <lug at leica-users.org> wrote:
> 
> Greetings to all.  The attached files are the same image processed in 4
> noise reduction programs.  The base image was shot at 25600 ISO and cropped
> to less than 50% of the image.  The camera was a Sony A1 and the lens was a
> Sigma 105 F1.4 at 1.4.  Take a look and decide, the only processing was the
> noise reduction, cropping, and lightening the overall image.
> 
> First is LR enhance:
> 
> http://gallery.leica-users.org/v/don_dory_gmail_com/Noise/LR+enhance.jpg.html
> 
> Next is the older Topaz denoise:
> 
> http://gallery.leica-users.org/v/don_dory_gmail_com/Noise/Topaz+denoise.jpg.html
> 
> Topaz AI:
> 
> http://gallery.leica-users.org/v/don_dory_gmail_com/Noise/Topaz+AI_.jpg.html
> 
> DxO deep prime although not the strongest selection:
> 
> http://gallery.leica-users.org/v/don_dory_gmail_com/Noise/DxO+deep+prime.jpg.html
> 
> 
> 
> -- 
> Don
> don.dory at gmail.com
> 
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