RGB: how to break up an image into these components?

[Peter Wassink]

In order to apply certain effects i am trying to break up an image into its RGB components.
each channel on its seperate layer
TVP used to have dedicated channel buttons that could be used for this.
But they were abandoned, now i'm not asking for their return but..., i am looking for the FXstack workaround (i knew it once, but can't remember) maybe someone has the answer ready?

[ematecki]

To split it into channels, I would use the BW Converter with each time a single channel at 255 and the other two at 0.

To merge them back the best would be a to colorize/tint each of the layers with they respective color and then just merge the layer stack.

There may be faster methods...

[slowtiger]

Shouldn't it be possible to script this and put into a button, so one click would copy the source layer into 3 separate layers for each RGB channel?

[Peter Wassink]

once i get the right settings it shouldn't be a big problem to get in into buttonform.

I'm not there yet though.
Eric how do i then set the layers so they display the original image, what blendmodes should i use?
i could puzzle away at this but before i do maybe someone knows already?

[ematecki]

It's even easy than I thought...

Once each of the three layers is tinted/colorized with Red/Green/Blue, just set their blending mode to "Add".
Don't forget to set the background to "None", adding over white stays white...

[Peter Wassink]

It's even easy than I thought...

Once each of the three layers is tinted/colorized with Red/Green/Blue, just set their blending mode to "Add".
Don't forget to set the background to "None", adding over white stays white...

and do the layers have to be set at 33%?
i'm not getting the original drawing back
And tint and colorize get me different results that is... only colorize will change the grey image into color.

[ematecki]

and do the layers have to be set at 33%?

No, they must be at 100%. Each one will only add to its own channel.

And tint and colorize get me different results that is... only colorize will change the grey image into color.

So use colorize :) I used a french version and didn't remember which one is which one in english, so I wrote both...

[Peter Wassink]

no luck yet

[ZigOtto]

no luck yet

Peter, don't use "Colorize" to get the color of your R, G and B chanel, but instead use "Multiply",
... then use "Add" mode for blending the 3 chanels again together,
so the "step by step" is something like that :
duplicate your original source 3 times, rename each layer Red, Green, and Blue,
to the Red layer, apply the B&W converter FX (R=255, G=0, B=0)
to the Green layer, apply the B&W converter FX (R=0, G=255, B=0)
to the Blue layer, apply the B&W converter FX (R=0, G=0, B=255),
now, paint over the whole Red Layer (rectangle fill) with the red color in Multiply mode,
idem on the Green layer with the green color, and on the Blue layer, with the blue color, all in multiply mode,
then, set the merge mode of the 2 top layers to "Add".

... or alternatively, use the Color "Shuffle" FX from the K-FramED plugin ...

[ematecki]

no luck yet :(

rgbchannels.jpg

You have to set the background to "None", not "Color".

[Hervé]

no luck yet

rgbchannels.jpg

You have to set the background to "None", not "Color".

Or select a pure black as background color

[Peter Wassink]

Peter, don't use "Colorize" to get the color of your R, G and B chanel, but instead use "Multiply",

that was it. now it works

Super!
merci beaucoup Zig

[Peter Wassink]

no luck yet

rgbchannels.jpg

You have to set the background to "None", not "Color".

i did (though not in the screenshot )
but as Zig pointed out, the 3 grey channels have to colorized using Multiply and not colorize/tint and that was where i went wrong.

Thank you all