I’m not sure if this is a bug, if I’m doing something wrong, or if this is expected behavior from Denoise AI… I don’t RECALL ever seeing results this drastically changed from previous versions, but if it’s normal to have such a drastic change it would be good to know.
I couldn’t find any discussions of the output from Denoise being drastically different than the input, but I’m seeing that, and I was notified by another Denoise AI user this morning that he too is seeing this from his Nikon RAW images.
I took a standard, moderately High-ISO (8000) RAW exposure from a Nikon D500 and made only basic exposure corrections in Lightroom – exposure, black and white points, shadows and highlights adjusted. White balance as shot, profile normal camera standard from the input, no Presence, HSL, tone curve or sharpening adjustments. Luminance noise reduction set to zero. No significant adjustments.
I generated a .dng file using the Adobe .dng converter, so the .dng file is virtually identical to the RAW image. I also exported a .dng file from the original RAW using Lightroom’s Export to see if that would make any difference. All three source images are essentially identical.
I started Denoise AI standalone, and added the RAW and .dng images.
I processed them through the Denoise AI method at the Auto values: Settings were N19, S37 with recover detail at 5. (just in case there’s a question of using Low Light instead, I did. I ran a second time in Low Light at the Auto settings, and the outputs were the same)
I processed the images with the output as .dng.
I then processed the images with the output as .tif.
Both the .dng and .tif outputs differ drastically from either the .dng or .nef input images.
Both the .dng and .tif image are identical for a given input. So for the output from the original RAW image, the .dng and .tif are the same, but drastically different than the input image.
The same holds true for the .dng and .tif images derived from the exported or converted .dng.
I examined all the images in Photoshop, using histogram statistics (mean, Std Dev and median) and threshold values (black point, midpoint and white point).
(unfortunately, I have no idea how to display a table in here)
File | Black pt | Midpt | White pt | Mean | Std Dev | Median |
---|---|---|---|---|---|---|
Original RAW | 1 | 128 | 248 | 103.32 | 49.29 | 100 |
DNG from RAW | 9 | 121 | 230 | 60.48 | 27.25 | 56 |
TIF from RAW | 9 | 121 | 230 | 60.48 | 27.25 | 56 |
Exported DNG | 1 | 128 | 248 | 103.32 | 49.29 | 100 |
DNG from DNG | 14 | 117 | 241 | 99.11 | 35.53 | 95 |
TIF from DNG | 14 | 117 | 241 | 99.11 | 35.53 | 95 |
Converted DNG | 1 | 128 | 248 | 103.57 | 46.77 | 101 |
DNG from DNG | 14 | 117 | 241 | 99.11 | 35.53 | 95 |
TIF from DNG | 14 | 117 | 241 | 99.11 | 35.53 | 95 |
It appears that the output from Denoise AI has significantly darkened the images and truncated the tonal range. The worst results appear to be from either .dng or .tif processed from the original RAW input. But all the outputs from Denoise AI seem badly compromised.
In theory, I’ve uploaded three images as small jpegs - the original raw, the .dng and .tif outputs from Denoise AI. Unfortunately, it appears I’m not allowed to upload images to this forum.
Has anyone seen behavior like this?