Color Correction for diving videos

[kopi]

Hello,

I recently made my first diving videos and they all have this greenish touch. Could you please recommend a video editor to fix this?
Googleing I found a video tutorial for GoPro Studio which looks promising but it's discontinued :/
On Ubuntu I tried AviDemux and Shotcut, but with both I couldn't get good results.
On Windows I haven't found any free tools, but opening a frame from a video in paint.net and using the Auto Level feature (I guess it fiddles with the histogram) leads to very good colors.

[Attachment 46061 - Click to enlarge]
[Attachment 46062 - Click to enlarge]
Unfortunately I wasn't able to get even close with any video editor I tried so far.

Thanks for any suggestions, kopi

[redwudz]

You're using Linux? Try the freeware Cinelerra There are some tutorials on YTube.
For Windows, maybe VirtualDub 2. Lots of filters available.
The included six axis color correction might be a start.
But I'm not sure if either handle GoPro formats.

And welcome to our Forums.

[shekh]

Look at this thread, might give some ideas: https://forum.doom9.org/showthread.php?t=175536
You can get Gopro Studio but it has very poor correction capability.

[kopi]

Hello and thanks for your tipps. All those programs offer some kind of color correction, but I couldn't find one that does it automatically for each frame. Since I've different depth in my video, the color correction would have to adapt quite often. So I tried AviDemux again and clicked through every filter. The Avisynth color filter has an option for AutoWhite. With this option the videos are not perfect, but ok.

[Attachment 46096 - Click to enlarge]
Would you know another program with such a feature that fixes every frame itself and not by setting a filter for a sequence or even a whole video? Tanks, kopi

[sharkbite]

Matey - what you are asking for is auto colour correction - this is not really how most editors work

Virtualdub2, davinci resolve, adobe after effects and even the old windows movie maker that came with w7 have correction,
but when i edit my u/w stuff, i do it per clip, and adjust accordingly depending on the depth,
and how much red has been taken out by the water.
in practice, adding some magenta, changing the gamma, and increasing the contrast to varying degrees can give a pleasing result.

this is where i learned how to do it:

https://www.youtube.com/watch?v=UGthOhEMSYs

I'm not aware of any s/w that can do the above automatically across multiple clips,
although clips taken at the same depth rarely require different settings

You can speed up the process if you carry a "white" slate to help set the white balance,
but i have found carrying an extra bit of gear a larger pain that editing in post.

You could also consider a video light - this brings all the colours out, and
for the lit subjects, no correction would be necessary

Hope this helps rather than confuse.

For specific advice on editing underwater footage, you may like to stroll over to:

https://www.scubaboard.com/community/forums/underwater-videography.343/

[KarMa]

[Attachment 46108 - Click to enlarge]
General visualization of water light absorption by depth, with red having the heaviest level of attenuation (loss). While cyan, blue, and probably purple have much less attenuation.

Edit: After looking at the photo there is very little Red information in comparison to the Green and Blue.

2nd Edit: Messing around in Rawtherapee I came out with this. There is just so little Red information, the rocks themselves have about zero Red info, with the white sand having a bit more.

[Attachment 46111 - Click to enlarge]

[amaipaipai]

Davinci does this quite easily, checking the Parade and Vectorscope, you'll get similar results, there's no much color information to work with.

BEFORE

AFTER

RESULT

I'm using GIMP as the next example, sorry I'm kind of busy right now, you can also do this in Davinci, to create your Red, Green and Blue channels or layers to subtract the diference between then to find your white, restore some of the details.

Then working layer by layer to reconstruct the shot, os do a post production to do a blue casting to it, colorize the sand, etc.

As people already told you, you need to prep to do underwater shotting for best results.
http://www.divephotoguide.com/underwater-photography-techniques/article/shooting-under...-video-basics/
http://www.untamedscience.com/filmmaking/advanced-filmmaking/underwater-filmmaking-basics/
http://www.uwphotographyguide.com/10-underwater-video-tips

[RobM]

I have settled on Shotcut for underwater video color correction. Here’s the recipe that I’ve discovered works best::

Import your clip(s) then:

Filter -> White Balance (use sand, skin, greys or whites to balance)
Filter -> Hue/Lightness/Saturation (small Hue adjustment +/-5%, reduce Lightness >5%, big saturation adjustment >150%
Filter -> Contrast (50-55%)
Filter -> Sharpness if necessary (40-50% works for me)

See https://youtu.be/9DiJbS1YYiA

I have also used “Filter->Color Grading” to fine tune these levels, but the above is the most efficient recipe I’ve devised so far.

Caution once you dive deeper than 15m then the reds may be too weak to recover - this is a consequence of greater light absorpbtion by the water. You may need to use underwater video lighting unless the underwater visibility is extremely good. Before you dive, make sure you ‘lock’ your camera’s white balance to avoid color drift.

I have produced a document of camera setup tips that might offer additional help - https://barnsleybsacdivers.co.uk/wp-content/uploads/2020/04/Underwater-Video-Workshop-v1.pdf

[Andy Willett]

Have a look at my article on video lights and using filters, you may find it helpful
http://underwaterwillett.com/ambient%20filters.html

[Selur]

Just wondering could something like https://github.com/Kiyamou/VapourSynth-DehazingCE be helpful with underwater footage ?

[Budman1]

Underwater lighting either by strobes, flash or standing lights is critical when photographing underwater. Different spectrum of light are absorbed in water, rapidly, with red being the first to be absorbed which is why at any depth at all, low light pictures appear green.


[Attachment 58218 - Click to enlarge]

[Selur]

Thought dehazing might help more with visibility than color adjustment,... if it doesn't that's fine with me. Just thought it might.

Cu Selur

[Andy Willett]

To help with colour correction for underwater video, it is often best to have artificial lights to help restore the colours.
This can also be assisted by using filters on the lens and or lights.
THEN post rendering will be much better
Have a look at my article and videos on the subject.
Let me know what you think

http://underwaterwillett.com/ambient%20filters.html

[Selur]

I read your link the first time you posted it and I agree that the best way is to avoid color and visibility issues during the capturing, but sometimes you have to deal with a video and do not have the option to recapture it.