FBDD algorithm?

szgabor · July 6, 2016, 4:24pm

Hi there,

what do you think of this de-noising algorithm?: http://www.linuxphoto.org/html/fbdd.html
It’s implemented in Photivo, and deals quite effectively with severe noise. It works on the raw data (thus maybe not that easy to port to RT). Any thoughts?

cuniek · July 16, 2016, 9:06am

I support the request. IGV + FBDD could be a killer combo!

szgabor · July 20, 2016, 1:48pm

No comment from the developers…?

Morgan_Hardwood · July 29, 2016, 2:01pm

Search the bug tracker.

patdavid · July 29, 2016, 2:39pm

github.com/Beep6581/RawTherapee

Raw channel noise reduction

opened 08:37PM - 11 Aug 15 UTC

Beep6581

type: enhancement

Originally reported on Google Code with ID 2679 ``` This is related to issue 26…24. I'm no expert on noise reduction so this may be a bad idea. However it seems to me a bit backwards to only apply noise reduction after demosaicing, so here's the idea: Noise in an image is roughly read noise from the sensor A/D conversion and photon shot noise. Both are dependent on exposure level, ie how close to clipping the signal is. After demosaicing and white balancing etc raw channels are scaled and mixed so you don't have the same direct connection to signal level. The red channel may have been scaled up one stop compared to the green for example. I'd like to test and see what happens if you apply noise reduction pre-demosaic (as a raw preprocess step in the raw tab) per raw channel, and with a curve to control noise reduction amount based on exposure level (ie typically no noise reduction on the top 4-5 stops or so, and then increase the amount towards the bottom). This would give you direct control to apply noise reduction based on how much noise there actually is in the signal. With the current noise reduction tool I lack control to adjust noise reduction based on how noisy the signal is, and I can't leave well-exposed areas without noise reduction. There is some control, but not enough for my own needs which is about refining low ISO images, not make high ISO images better. ``` Reported by `torger@ludd.ltu.se` on 2015-02-20 10:55:12