Channel mask To Layer mask...how to?

[naveen]

Hi folks..how can i copy any mask from "channel" to layer mask.i want to modify my blue channel and use it as a mask for my layer,i know i can press Ctrl and load that channel as selection and make a mask of that selection in layer but by doing that i loose details at the edge.is there any way to drag that from channel tab to layer?i can even copy any channel and paste on layer but it pastes on new layer which is not i want.

Any help will be appreciated.

Thanks

[nickmarshallvfx]

Hmm, im not sure exactly what you are trying to achieve, but here is my process for using channels to pull a matte:

- Go to the chanels and find the chanel that has the highest contrast between the 2 elements you are trying to seperate.

- Use levels, curves and painting to get complete black and white seperation.

- Invert the colours (Ctrl + i)

- Load it as a selection, and move back to your layers pallette.

- Duplicate the layer, and add a layer mask to it.

- Use the selection to fill the layer mask, which will leave you with the seperated element on a layer of its own.

Hope that helps a bit.

Nick

[thenextside]

Naveen,

What you describe sounds right. It should be exact. The detail you are loosing is from image information that resides in the red and green channels.

Hope that helps.

Tim

[naveen]

Hey Nick that is exactly what i follow usually but once you load your matte as selection it loses some information,say i have matte of a tree with details in leaves n all,when i load selection for that matte i lose information at edge of leaves.

Tim you are right sometimes information resides in red and green channel but how to use that information without loading the matte as selection.

I guess if there would be some way to use channel without loading it as selection can solve the problem.

Thank you Tim and Nick.

[thenextside]

You can try doing a contrast adjustment on the matte but then you may end up with fringing. Trees can be really tricky sometimes. Especially if there is some light spill or those lovely red and blue color abortions that you get with digital photos. Can you show us the photo your trying to pull a matte from?

[nickmarshallvfx]

Trees can be incredibly difficult, and i find they usually require a lot of hand painting. You could try expanding the selection if you find you are losing some information? Then if you find that this helps to retain the information but you get a rim around the trees, you could do a matte defringe to try and help.
Thats just anther option to try in case you are losing the information some time between the stage of moving from channels back to layers.

I agree with thenextside, can we see the photo?

Nick

[naveen]

Hey Tim...i use adjustments like contrast,it helps many times.

Nick ya expansion helps sometimes and i do have to paint for adjustment almost all the time.

Rightnow i am not talking with reference to any image that i am working on,it just that very often i come across this issue on projects,so ive nothing to show you guys.

I appreciate you guys helping me out with this.

Hey tim you know what i just clicked to your webpage link,i had visited your site sometime back and downloaded your reel.its truly awesome.fisrt one(babel)is my favourite.

Thanks

Naveen

[naveen]

hey..recently i found the answer to this issue..when i make a layer mask to any layer,the same mask also shows up under channel tab,so i just have to copy my modified r/g/b(anyone) channel to that channel and it automatically gets updated in layer mask also,thats something i never noticed before...its simply great.

cheers