Can I make a layer mask out of an image?

[S***@adobeforums.com]

Okay, I need to know how to make a black and white image into a layer mask. Please somebody help, this has been bugging me for days.

Any help would be much appreciated.

[G***@adobeforums.com]

Shann

1) Put the black and white image below the image you want to be masked.
2) Move your curser between the two images holding down the Alt key
3) When the cursor turns to two interlocking circles right click the mouse

That is it you can even use shades of grey from white to black to paint on
this mask as well as erase part of it.

g.

[S***@adobeforums.com]

Grant - that will only work if the B&W image is in fact black&transparent. Unlike layer masks which use black and white shades to determine the visibility of the masked layer, using grouped layers like this for masking relies on the degree of opacity rather than the shade of grey. So first you need to get the image into degrees of opacity rather than shades of black and white. Richard Lynch's Hidden Elements book has some very useful one click tools for this, but you can do it yourself without add-ons (I've just got to remember how!)
OK
This is longwinded and there may well be an easier way of doing it!
The first steps in this show how to add a black and white image to a layer mask in an adjustment (or any other layer - which may be what the original poster is asking for)

1.Create an adjustment layer (any sort - doesn't matter)
2. Select and copy the image to be used as a mask. Deselect.
3. On the layers palette - hold down the option key (I guess alt for windows) and click on the mask icon of the adjustment layer. This will turn the image white - you are looking at the layer mask now on the screen
4.Then paste. The luminosity of your image is then the layer mask.

This is useful to get complex masks for adjustment layers such as levels HSB etc. If you have one of the downloadable add-ons then it's all you need as they give you layer masks for any layer.

If you don't then there are a few more steps to being able to use Grant's method:

5. option/alt-click the layer mask icon again again (to return to the normal view)
6. command (control for windows)-click on the mask icon. This loads the mask as a selection - really useful if you want to use a saved selection as an alpha channel for those filters that can use them such as the lighting filter.
7. Create a new layer. With the selection still active fill with black. This will give a layer that has the darkest tones in the image to be used as a mask as black and the lighter tones as less and less opaque and can be used as Grant suggests by grouping a lyer to it. If you want to have it the other way about (ie the inverse of this mask) you need to inverse the selection first and then fill. To modify the mask thus created paint with opaque colour to show the image, erase to transparency to hide.....

I think that all works. Based on material by Jay Arraich and Richard Lynch. Any errors are mine....
Susan S.

[E***@adobeforums.com]

Post by S***@adobeforums.com
Grant - that will only work if the B&W image is in fact
black&transparent. Unlike layer masks which use black and white
shades to determine the visibility of the masked layer, using grouped
layers like this for masking relies on the degree of opacity rather
than the shade of grey. So first you need to get the image into
degrees of opacity rather than shades of black and white. Richard
Lynch's Hidden Elements book has some very useful one click tools for
this, but you can do it yourself without add-ons (I've just got to
remember how!) OK
This is longwinded and there may well be an easier way of doing it!
The first steps in this show how to add a black and white image to a
layer mask in an adjustment (or any other layer - which may be what
the original poster is asking for)
1.Create an adjustment layer (any sort - doesn't matter)
2. Select and copy the image to be used as a mask. Deselect.
3. On the layers palette - hold down the option key (I guess alt for
windows) and click on the mask icon of the adjustment layer. This
will turn the image white - you are looking at the layer mask now on
the screen
4.Then paste. The luminosity of your image is then the layer mask.
This is useful to get complex masks for adjustment layers such as
levels HSB etc. If you have one of the downloadable add-ons then it's
all you need as they give you layer masks for any layer.
5. option/alt-click the layer mask icon again again (to return to the normal view)
6. command (control for windows)-click on the mask icon. This loads
the mask as a selection - really useful if you want to use a saved
selection as an alpha channel for those filters that can use them
such as the lighting filter.
7. Create a new layer. With the selection still active fill with
black. This will give a layer that has the darkest tones in the image
to be used as a mask as black and the lighter tones as less and less
opaque and can be used as Grant suggests by grouping a lyer to it. If
you want to have it the other way about (ie the inverse of this mask)
you need to inverse the selection first and then fill. To modify the
mask thus created paint with opaque colour to show the image, erase
to transparency to hide.....
I think that all works. Based on material by Jay Arraich and Richard
Lynch. Any errors are mine....
Susan S.

I end up with a transparent window.

Ed

[S***@adobeforums.com]

Ed - that's odd. I'm trying to find where I went wrong - but the instructions work for me, I think, on PE2 - i just double checked them. Probably I'm missing out something crucial that I do automatically without thinking about it or I've not made it clear which layer I'm talking about. Where does it go adrift?
Can you see the greyscale version of the image appear in the adjustement layer's layer mask thumbnail after step 4/5? If it didn't then there's a problem with pasting the image into the mask (I'm guessing about the keystrokes for Windows - I don't have the crib sheet for Windows keyboard shortcuts and that's the only place that I know that this stuff is documented)

If that's OK, then when you command (apple) or control (windows) - click on the resulting layer mask thumbnail in step 6 you should get a selection showing in the main image window that roughly corresponds to a division between the light and dark portions of the image. (it's pretty much the same as if you used the shadow mask tool from HPA3)
Then make sure you have the new layer active and the selection still active when you do step 7. As a result of the black fill you should have a layer which looks like a rather pale transluscent negative of the original black and white (I actually got this back to front in my description of step 7 in my original post). This - when grouped with a layer above this - will show through the areas of the top layer that correspond to the brighter areas of the greyscale image that you want to use as a mask..... to get the reverse effect then invert the selection before filling.

Does that help or have I muddied the waters further?!!

Susan S.

[E***@adobeforums.com]

The original post refers to a "black and white image." You use the term "B&W
image."

Are you, the original poster and Grant referring to the same thing?

Ed

[S***@adobeforums.com]

Ed - I meant by my (overloose) use of the term B&W a greyscale image that is just composed of tones of black, white and grey in between - the sort of thing that you get when you use the remove colour command on an RGB image. The method of copying and pasting into a layer mask that I (attempted to) describe would work with a pure black and white (no grey) image too - if this is what the original poster meant... - it also works if you choose a RGB image as the starting point for the mask - in this case it pastes the luminosity of the image (or something pretty close to it) into the layer mask - this is the way that I have used this technique in the past.

I obviously shouldn't try to write instructions to do things before my second cup of coffee in the morning! As it is now 11.30pm here in Aus I will retire to bed!