[Bf-vfx] Keying nodes

[François T.]

here are my 2 cents, I don't think the actual nodes are that bad though, I
just think the UI makes them really hard to know/see what you are doing.
And as a general purpose they are missing some falloff features. The output
quickly ends up clamped which you always need to ramp/blur/level thing.


Difference Key:
> This takes the difference between a clean plate and another plate and
> determines at a per-pixel level if the two pixels are different within
> an RGB color space (with an adjustable tolerance and falloff).  This
> node works really well if your clean plate and keying plate are lined up
> perfectly, such as when using a tripod to shoot the image or using a
> motion control camera.
>

In most application and cases that does not work that great. if too much
noise (raw file) changing lighting (projected shadow,...) I wouldn't put
too much energy into it



> Luminance Key:
> This uses the luminance value (in YUV color space) and a high/low slider
> to determine if a pixels should be keyed or not.  This is useful for
> anytime the foreground is significantly brighter than the background.
> Such as  keying special effects like fire/explosions/fireworks/etc for
> comping over other scenes later.
>

IMO this is a case where the UI could be made much better, showing an
histogram for instance to spot where the luma are.
and again some fall of wouldn't be too much :)
http://www.pasteall.org/pic/30219

HSL keyer on the same principle where you can select a range is good as
well. http://aescripts.com/efx-keying-alpha-plugin-suite/




>
> Distance Key:
> This keys pixels based on the 3 dimensional distance between colors in a
> 3D RGB color space.  This key works well when trying to single out a
> specific color in a background (not necessarily green).  This key
> requires the patch I submitted a couple of weeks ago to fix the sliders
> from being dependent upon one another, they should be independent.
>

Same for distance key, displaying a cube with 3D colors, maybe even being
able to select them into the cube could be nice (ie Magic bullet looks
Keying)
https://vimeo.com/13310977

or something more simple with 3 type of color selector. Main Color, color+
and color- to refine color selector



>
> ____________________
François Tarlier
www.francois-tarlier.com
www.linkedin.com/in/francoistarlier
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