Can I "erase transparency" in a photoshop file?

Photoshop 7.0: Alpha works automatically.

Photoshop CS2: I need to create an alpha channel (easy) and a 100% opaque version of the image (problem)

How can I convert a layer (or set of layers) that has less than 100% opacity into a layer that has 100% opacity and the same colour information? Currently the best workaround I can come up with is make a huge stack of the same layer, over and over and over, so eventually that 10% opaque pixel is almost 100%.

Matting things down to a single colour background is not acceptable; If I had 50% transparent stripes of red, green and blue there's no way a single colour background could be used. I can lock transparency in photoshop, but what I need is a way to lock everything else; hold red, green and blue values the same and let me set the alpha value to 255.

If this can't be done I'm going back to the Photoshop 7.0 "bugged" TGA alpha system, at least for most things.

Hi Nepenthes!

It's easy to make the solid too. Download the Flaming Pear Free Plug-ins here, (about 3/4 of the way down that page,) install them, make a copy of the image at the bottom of the layer stack, and run one of the three Solidify filters.

To make that copy quickly in CS2, if you have a single layer image, just hold down Option/alt then drag the layer down.

If it's a multi-layer image, make a new layer at the bottom of the stack (Command/ctrl and click the New Layer icon) and then, with that layer selected, hold down Command+Option+Shift (ctrl+alt+Shift on a PC) and tap the E key to make a composite layer. Run the filter on that, and you're all set.

Nice, bright, true colors, without any halo.

Hope this helps!

Perfect; thanks Robin!

Part of my export action is to duplicate the current image as one composited layer, so I can just run solidy on that. Now I have it setup so F12 spits out TGAs using the alpha channel, and shift-F12 spits of TGAs of whatever was visible, no halos.

Easy halo-free TGA export action (a.k.a Photoshop 7.0 style)

1) duplicate the image, select "duplicate merged layers only"
2) select (ctrl-click) the layer (there will only be one layer)
3) save selection as an alpha channel
4) deselect
5) run solidify-A
6) save as a 32 bit TGA file.

You are most welcome Nepenthes!

And I like your Duplicate Image trick, to make a flat file while preserving the layered one. I'll have to start using that myself. It'll save me a step, in my own workflow. Thanks!

For readers who might not know how to Duplicate the Image, it's under Image > Duplicate. More detailed instructions have been added to the Transparency sticky at the top of the forum.

(I hope you don't mind, Nepenthes, but some of our readers don't know PS as well as you do. )

Not at all! Because "Robin explained my instructions better than I did and now I'm all upset at him!" seems like such a silly idea.