Is there a way to convert RGB sensor noise to luminance noise using #RawThera...


(#Woctxphotog) #1

(Mica) #2

If you can post your question instead of just a link, that would be helpful to people who find this later.

Also @Morgan_Hardwood, who answered you on G+, is a developer and RT super user.

Turn on noise reduction, that is the answer!


(#Woctxphotog) #3

Is there a way to convert RGB sensor noise to luminance noise using #RawTherapee? I hate rgb sensor noise, so I normally just convert the whole photo to black and white. But on occasion I need to find a way to keep it in color. I have been using rawtherapee for years, and have gotten pretty proficient in using it. Expect when it comes to killing the rgb sensor noise. I often do my best to limit it with adjusting black levels but that does not always work. So is there a way to convert rgb nosie to black and white luminance noise? Or could it become a feature down the road? Follow the link for full discussion. Here is a raw file so you can see the noise I deal with, This photo was taken using
Olympus OM-D E-M5, M.Zuiko Digital 1.4x Telecoverter MC-14, Metabone N/F-M43mount Tamron Adaptall 2 28mm 1:2.5 @ F8 1/30s ISO6400 28mm_7090017.ORF (17.5 MB)
this is just an example, and often the same issue I deal with as far as noise is concerned.


(Alberto) #5

Hi,

I’m not sure I understand exactly whta you mean by “converting”, but what you can do in RT is limit the noise reduction to the chrominance channels only, and leave luminance untouched. Here’s an example, I think it worked pretty well in this case (but YMMV of course):


_7090017.ORF.pp3 (10.6 KB)


(Morgan Hardwood) #6

Enabling the Noise Reduction tool and using only chrominance noise reduction leads to that film-like look with only grain. Original on the left, chrominance noise reduction-only on the right, notice no color blotches on the right (zoom in to 100% or more when viewing these screenshots):

If you like, you can reduce the luminance noise using the median filter:

and/or luminance noise reduction:

_7090017.ORF.pp3 (10.4 KB)


(lux) #7

HI all

It seems to me that the first thing to do is to use either LMMSE or IGV as a motor RAW.
Later, to use “luminance” and “chrominance” ~2 to 3% each (both in RGB mode and high quality).


#8

Or if you have access to a dev build, use AMAZE+VNG4 (or RCD+VNG4)


(#Woctxphotog) #9

Hey everyone, thanks, I will look at what is going on later today when I am back at my computer. I have done all that you have suggested. I never get those results. I always have excess rgb noise that is very visible. I guess I have to look and see if maybe it is my monitor creating noise that is not there. You all have done what I always try to do. On my laptop those look fine. But I dont work photos on my laptop, its too small for me. Anyways. Thanks for the input and I will re-evaluate what I have going on in my workflow and hardware.