RawTherapee noise on sky at resize

Hello to the community!

Recently I switched to RawTherapee 5.8 and I processed a .nef file for uploading it to airplane-pictures.net.

To upload to that site you need to resize your image to up to 1600p the largest side of your image among other things (one other of those is to upload it to jpeg)

On whatever picture I uploaded there with sky on the background I have been screened by noise on it.

I suspect the resize module since I have no other processing modules that might add noise to the image. Image itself is shot with 220ISO on a Nikon D4.

Settings/attributes on Resize module are:
Applies to: Cropped Image
Method: Lanczos
Specify: Scale
With scale slide to 0.38 approximately (if I remember correctly)
Cropping has not applied to image so cropped image in applies to concerns the whole image.

Note that I have tried different methods of demosaicing (currently I am in AMaZe+VNG4).
Note too that I have used Gimp for eliminating dust spots of sensor and in all processes for exporting the image to jpeg I use best quality with 100% jpeg compression (i.e. less compression as possible).

Image can be available for viewing if requested. Please specify a place to uploaded to.

Every help appreciated
Thank you in advance

You can upload a file directly to this site. It would be helpful to have a sample .NEF file so we can try to replicate the problem. Also, I don’t know what kinds of changes have happened to noise reduction in RT since 5.8 stable, but have you tried a release candidate build?

Ok. I’ll try to uplaod here the .nef plus the resized image as I posted on the site mentioned on my firts post…

.pp3 file would be useful too I suppose.

I really do not know what a release candidate buld is. Are you talking about the upcomming 5.9 on dev release?
RawTherapee.7z (20.6 MB)

Can you elaborate on what you mean by this? I have opened your NEF and it doesn’t have any significant noise in the sky. Exporting to JPEG (Quality 90) and zooming in gives me this:

I would not call that noisy?


Dev builds from here: Release Automated Builds · Beep6581/RawTherapee · GitHub

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Well, the actual picture I am uploading on the site I mentioned is also included in the zipped file I uploaded.

They did found noise in it. I suppose they are the experts. Personally I will go along with that. Yet I might suggest that noise is a bit subjective and it depends on what level of magnification someone will agree that there is some noise in the image or not. Is there a way to measure noise practically on an image? For example I did use the “sharpening contrast mask” button to see if there is noise on the sky (I did not find any)

I looked at your jpg on my phone, IMHO sky is smooth as a baby’s cheek.

Maybe the noise in the sky is the helicopter… ? :crazy_face:

Oh, and welcome to the forum.

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I’m not seeing any noise either. Is it possible your submission got rejected in error? Are you allowed to resubmit?

I’m wondering about this since the jpg offered in the 7z has noise.

Allthough it’s not much and within normal limits, I think. I’m also wondering about the provided pp3. It doesn’t seem to be the edit leading to the enclosed jpg. It also doesn’t have noise reduction enabled. Have you tried using it? I have always enabled it by default whatever ISO the photo has.

Yes. You are allowed to resubmit. I have already done so. The image passes each time from two screeners, both of them twice agreed that the image has noise. Second time I’ve changed the demoseicing method and resubmitted the image (as well as did my best to clean the image from spots due to sensor dust).

I did not used nose reduction since the image is shot with ISO 220 so I am not into using modules that I should not to. And as all agree there is no noise on the RAW file in the sky at least. Thus I suspect the resize module for start for the jpeg file.

I did use Wavelets though I do not know if this is relevant. Generally I use the less and most necessary post processing as possible.

But my question remains: Is there a non subjective way to measure noise on the sky after the image has been exported to jpeg? Via RawTherapee or Gimp or another online tool?
And finally does resize as a module imposed noise on low frequency areas such the sky?

@markman8 welcome to the forum.

what i can see, there is almost no noise, but artefacts and switching off the dehaze-module will smoothen the sky a little bit more.
Noise reduction with low values (Lab, conservative, Luminance 0,1 to 1) also can help.

Btw: in the pp3-file you added, the resize modul is switched off? And why not use the resize to height (=1600)?

Then: You are using sharping twice (presharpening and sharpening module) , this will bring artefacts to the surface of the helicopter and to the sky.

and last not least: as already redommended, give the dev a try :wink:

Hello @marter and thank you for welcoming me! Nice to meet you too!

Understood about the settings you recommend. I will give them a try after installing the dev distribution.

And you are right about the resizing module. I did deactivated (and I always do) after my exporting action for not to be forgotten for next exporting actions too. This resize action was only for the specific site. I did not know that by setting the height=1600 would do the job :smile: so I did by trial and error found the 0.32 value in the resize attribute.

Thank you a lot!

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playing around with your pic, i found this

(your edit left, my edit right side)

its not really obviously different, but then, by overcooking the tonemapping, you will see the differences in the sky:

Then, after you installed the newest dev-version, see this pp3-file, created by the dev AppVersion=5.8-3140-g292412831 Version=349

NIKON D4_17-Sep-22_3549_16581…jpg.out.pp3 (15,6 KB)
(i am not sure, if i chose the correct LCP-file for your lenses)

BTW: the spot removal tool does a really good job before resizing, no need for to do this in Gimp.

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Awesome work @marter !! Indeed there is a huge difference! I’ll try and work out the whole process from the .pp3 file you provided!

I did install the latest dev version and already shows quite promising.

Thanks a lot!

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Well I cannot make that .pp3 file you provide work with the software. It keeps overwriting it every time I open the file from the file browser to the editor for some reason. Even if I copy and paste the contents of your file to that newly created one from the RawTherapee [Version]
It still wants to create that default 15kb fresh .pp3 file. I do not know why. Next step is to study the contents of your .pp3 file and try to replicate it. I’ll do that next.

The lcp file is this: Nikkor_500mm_f4_P_ED_LCP on dropbox. Note that Vignetting is probably wrong as I read from the RawPedia notes about creating the profile for any lens. I remember that it is mentioned that you to not use laptop screens to set the vignetting and I did using Lightrooms program for creating tat LCP file. I have the whole process on a video uploaded to YouTube here

@markman8 after opening the .nef, on top right, beside “profiles”, you will find some icons. just click the first one ( the folder) and open the downloaded pp3 from disk.

Thx for the link. I saw, that the vignetting in your edit looked some kind of strange (like negative vignette) , thats why i chose another lcp.

Another thing you can try using the Dev version is applying noise reduction to just the sky (thereby preserving all other detail). To do this:
-Add a full image spot and move the spot to the upper left sky
-Add the Blur/Grain & Denoise tool
-Select Denoise and Set the scope to 5 so it just selects the sky (you can verify by enabling ‘Preview /\E’ and seeing what is highlighted)
-Set the mode to aggressive as there is no detail that needs to be preserved

I would not work that out myself. Not in a hundred years! Thank you very much for the guide.

Though I did resubmit my images once again and wait for once more to see if I will pass the screening process. If they fail and this time I will resubmit last one using your settings. Then all I’ve got is to tackle the screening process by asking their forum for opinions. I do not think that I have much luck over there though…

I have to emphasize though except from the millions of combinations on settings for each image (which is good in my opinion) the fact of portability on settings and adjustments for each RAW file. I use separate computers working on images and all I have to do is to carry with me the RAW file with that .pp3 magical file with all the settings needed done in written in it. Wonderful stuff!

Personally I have never used catalogues for my images so this transition to RawTherapee was a successful one! Thanks all people that helped this project become possible and real!

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I would not work that out myself.

That is one of the joys with this forum :slight_smile:
You can’t imagine how much I have learnt from it;
hopefully, you will enjoy it as much.

Have fun!
Claes in Lund, Sweden

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