Quote:
Originally Posted by shekh
@Bryan: It may be good idea but it will definitely blow up the filter (more complex math and UI). So maybe another one. Never had success yet with shadow-highlight separation, maybe it is too subtle for me
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T'was just a thought. Maybe could be applied through masked overlays, but that's not something I've really explored in Vdub. There's RGB (gradation) curves also, of course -not for the faint hearted.
Quote:
Originally Posted by shekh
Interesting that you applied channel mixer, I supposed that red-green and yellow-blue sliders achieve the same
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Yes, with that first 'green-cast' sample (Test#1), using the '6-axis' filter alone I can get pretty close to the color balance obtained with Channel Mixer + tweaked with '6-axis'. But with the 'blue-cast' clip with the blanked red channel that Tormento provided, no, at least not to end up with an orange finned fish
It was the same in Resolve - pushing the color wheels to the extreme was not enough - always fighting an offset cast; the red channel needed reconstructing.
Also I wanted to see how well I could replicate the Resolve workflow using VDub.
Quote:
Originally Posted by shekh
Also levels... is exactly the purpose of top slider (intensity). Have you tried?
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I didn't in those examples, but I have now. Sometimes I just use curves when manipulating levels and contrast (S-curve) at the same time.
Quote:
Originally Posted by shekh
I'll try to pick some decent shots for experiments, if you want.
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Thanks, it would be interesting to test some good quality, native clips with strong casts/blanked red channels, ideally including sea life with known (and unambiguous) color characteristics, to see how well these methods hold-up.
Actually I just figured out an easier way to do the channel 'reconstruction' (redistribution) using what Resolve calls a 'Splitter-Combiner' node - basically splits the input into monochrome R,G, B channels with a separate node for each, so you can work on them independently, and combines them again. What I've done is to create blend (composite) overlays (layer nodes) between the monochrome G and R nodes and G and B nodes, with the G feed as the top layer and 'Add' as the blend mode. In that way, the redistribution of G channel luminance can be controlled by balancing the opacities (key gain in Resolve) of the two layer nodes. Fine tuning is then largely a matter of adjusting Color Temperature/Tint. Works very nicely and much easier than nudging individual sub-channel values.
Thinking about what I said earlier:
Quote:
Originally Posted by WorBry
I could be wrong, but I think the chances of coming up with an AVS plugin for 'automated' underwater color correction are pretty remote. Closest I could imagine would be a Channel Mixer based function that maybe has generic presets for depleted channel reconstruction when there is blue or green bias, which can then be tweaked.
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That's something that could applied in AVISynth (I think) - a Channel Mixer function (with sub-aqua absorption biases in mind) controlled via layer blend opacities.
Quote:
Originally Posted by shekh
@StainlessS: It honestly looks in real water like the unprocessed from camera.
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It's been many years since I last went diving (mostly Red Sea and Persian Gulf), but that unprocessed sample with the strong green cast (Test#1) is really how it would have looked to the diver? Maybe I never went deep enough. Is that where the phrase 'looking at the world through rose colored goggles' comes from ?