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Improving the colour blending


Magnymbus

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I noticed (quite recently) that when dealing with blending colours, the software must be using the lazy method that goes something like (PixelA+PixelB)/2. which is forgetting that computers essentially square root those colours (It's actually a Γ (Gamma) root), so you are making an average of a square root when it should be the square root of an average. The fix is to do (PixelA^Γ+PixelB^Γ)/2 where Γ (Gamma) is equal to somewhere between 1.8 and 2.2, depending on what took the image and what your monitor settings are. If there is an option for this already, I haven't been able to find it, but it really should be on by default, and it really shouldn't be without the proper mathematics. Minute Physics on Youtube recently made a really great video that explains this better than I did and it was that video that finally convinced me to do this. Anywho, here's a link to that: https://www.youtube.com/watch?v=LKnqECcg6Gw 

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I've just experimented with the code for 'Gradients Galore' to test what happens if I raise the BGR values to a power, mix them, then take the root.
The difference seems to be that the mixed region is lighter for higher powers - but I don't see any advantage?. Red to green gives more yellow in the middle but for most colour combinations the transition colours are just a lighter version of those achieved at power 1.

As for the built-in blurs, many other effects depend upon them so they cannot be changed. If you wanted to write your own effect using this idea (gradient or blur) then do give codelab a try.http://forums.getpaint.net/index.php?/topic/880-codelab-for-advanced-users-v25-released-march-14-2015/

 

Red ochre Plugin pack.............. Diabolical Drawings ................Real Paintings

 

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  • 2 years later...

I just found this topic so tried playing with CodeLab. On top is the Gaussian Blur, the bottom section is a custom blend which seems very different.

 

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MyBlur.cs

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Blends and blurs are very different operations. I'm not surprised they are different.

 

I see this is your first post here, so first of all - welcome :)

 

I'd like to point out that this thread is a couple of years old. We like to avoid posting new comments on old threads. It keep the forum current ;)

 

If you wish to restart the discussion on the differences between blending and blurring please start a new thread. Thanks!

 

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