Photoshop layers

Psyk · 7 Jan 2008 at 17:21

I'm trying to do some image compositing in photoshop. I have two images, one with an alpha channel. I want to paste the one with alpha channel on top of the other taking the alpha value into account. I've tried simply copying and pasting into a new layer, but it's copying the background colour as well. But I want it to display the pixels from image1 where image2's alpha is 0, and pixels from image2 when it's 1 (and all the values in between). Sounds fairly simple but I don't know much about photoshop. Any help appreciated.

edit-typical, I figured it out about 1 second after making this post.

Ross1234 · 7 Jan 2008 at 19:51

did you select the pixels with the alpha value?

Psyk · 7 Jan 2008 at 23:12

I selected the RGB channel and then ctrl-clicked on the alpha channel.

Shoseki · 8 Jan 2008 at 03:12

Hmm, let me offer some options as I don't quite know what you are talking about.

Do mean you mean you have a grey scale image you want to use *as* the alpha channel? in which case select the layer, ctrl-a ctrl-c to copy the entire layer, select the layer you want to apply the mask to, go into quickmask mode and ctrl-v to paste it in, then exit. Delete will remove the *inverse* of the mask, ctrl-i delete to apply the mask.

Alternatively, if you have one image already with an alpha channel, but the layer is locked (god knows I don't know how to unlock layers) copy the entire layer with transparency, and paste it into a new layer, duplicating it. Delete the locked layer. Now create a new layer beneath your recently copied layer, and paste the other image into it.

Psyk · 8 Jan 2008 at 15:51

Shoseki said:
Alternatively, if you have one image already with an alpha channel, but the layer is locked (god knows I don't know how to unlock layers) copy the entire layer with transparency, and paste it into a new layer, duplicating it. Delete the locked layer. Now create a new layer beneath your recently copied layer, and paste the other image into it.

Sounds complicated. Ctrl-clicking worked

It's probably the same thing, I just found a short cut.

The image with the alpha channel only has one layer though. I just wanted to take the entire image, including alpha channel and make it a new layer in another image.