Dehaze equivalent in darktable or RawTherapee

@Michael_Moreau
That’s what I would do to to your Shot:

  • white balance (spot white balanced on the whole frame then tweaked it a bit)
  • slightly pushed the blacks
  • curves to make the dark parts a bit more dark and bring out the milkyway
  • a double dose of velvia to bring out the colors
  • pushed the low frequencies in the equalizer a bit to bring out the milkyway some more
  • denoise profiled with wavelets for chroma and non local means for luma
  • finally some RL deconvolution from G’MIC, set to exponential
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looks even better than the LR dehaze. imho. mind to share the xmp?

There you go: http://29a.ch/tmp/IMG7492.CR2.xmp

I want to propose another sample image… :wink: Last week-end I went to the Alpago mountains in Italy, the humidity was quite high and so was the fog in the distance. I shot this picture of a paraglider with a very foggy background. I think this could be a nice test bench. I was inspired by some of the corrections suggested by @Jonas_Wagner.
Here what I applied with darktable:

  • white balance corrections
  • base curve and tone curve tweaking
  • velvia and vibrance enhancements
  • color zone tweaking to improve the greens in the lower part of the image
  • equalizer to increase clarity
  • denoise profiled (wavelet for chroma - non local means for luma)


darktable output (left) - in-camera jpeg with default settings (right)

What do you guys think? The colors recovered don’t fully convince me. Maybe I went to far with the saturation… Unfortunately I don’t have a Lightroom copy to compare its dehaze algorithm.
If you want to experiment with this image feel free to use the RAW file: https://drive.google.com/file/d/0B28JOPvq926IZllFTGlaS1VINk0/view?usp=sharing (updated).

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Oh paragliding, I love paragliding :smile:

The file you linked is a JPEG. IMO you recovered a lot already, you are approaching the noise floor when looking at the background. So honestly I’d probably not push it any more. I probably wouldn’t push it much more. The colors you recovered are nice (to me at least). I think you should play with the saturation a bit though. IMO the sky/haze in the background is too saturated.

Did you apply @Jonas_Wagner’s xmp to the image? Your result feels very Velvia-ish to me (not a bad thing necessarily, just takes a minute for my eyes to adjust to it again). :slight_smile:

@Jonas_Wagner thank you for the comment. Sorry, I linked the wrong file! Here the CR2 file: https://drive.google.com/file/d/0B28JOPvq926IZllFTGlaS1VINk0/view?usp=sharing. Probably is exactly the saturated haze the thing that doesn’t convince me. Here an improved version, I desaturated a touch the haze:

@patdavid, I started the RAW developing from scratch bud I had a look at the @Jonas_Wagner xmp file. By the way, thank you for all the efforts you put in pixls.us, I really appreciate the new articles look and this new forum!

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Thanks! Played around with it a bit. Arrived at a similar result to yours.
A tip for when you take another shot like that: Expose it to the right (make the image as bright as possible without loosing to much detail in the highlights). That way you will have a lot less noise when processing.

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The exposure is set longer because I was shooting stuff for a timelapse, not to full-rez pixel peeping :wink:

I was more worried about using a lower ISO setting to capture a cleaner full image than about star trailing that wouldn’t be apparent when down-sized to 1920x1080 (or roughly 2MP).

Today I come across this thread while looking for sharpen methods. I found this very interesting. I was playing a little with one of the images.

I would like to share the results I got. I’m pretty new to raw editors and I have many problems while masking. By the way, I think that the results are reasonable

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Someone has started working on haze removal IOP for Darktable.
See GitHub - rabauke/darktable: darktable is an open source photography workflow application and raw developer.
It works quite well already and will hopefully make it into the next point release.

.mm

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Meaning this branch: https://github.com/rabauke/darktable/tree/haze_removal ? It seems it was merged into master, and should appear in darktable 2.4.0.

Has anyone compared with LR6 / the above techniques?