I have a pretty decenty grap of alpha channels, but I was thinking today, there must be an easier way to do some of this. I have a few questions about handling alpha in photoshop.

Firstly. Is there any way to remove partial alpha? Like a filter that converts all pixels to either completely transparent, or completely opaque, dependant on how much alpha they currently have. Partially alpha edges of things gives an annoying blurry look.

Secondly, is there a simple way to select all transparent pixels in a document? The magic wand is a sketchy method at best, but I need some way to do this for creating alpha channels. One thing I've been doing so far, is creating a background layer of some unused color, like bright pink. Merging all layers, then using select color to select the pink area, and set that as transparent with an alpha channel. This method doesn't work so well with partially transparent pixels though, and I'm left with pink-tinted edges, which is annoying.

Lastly, is there perhaps some simple automatic method to generate an alpha channel? I use .pngs quite a lot, and I like them because they have a "what you see is what you get" thing. If something looks transparent in photoshop, it's transparent in the png. Seems to make it's own alpha channel. Most other image types don't work like this though, is there some way to have an alpha channel automatically created from transparent pixels in the document ?

*Secondly, is there a simple way to select all transparent pixels in a document?

If you press Ctrl and click on the little preview window of your layer, it will select all the pixels that are visible on that layer so if you then go to Select/Inverse you should have all your transparent pixels selected.

I don't use alpha channels all that much so I'm going to leave the questions about them to those who are probably more familiar with them then I am.  ;)

Quote - Firstly. Is there any way to remove partial alpha? Like a filter that converts all pixels to either completely transparent, or completely opaque, dependant on how much alpha they currently have. Partially alpha edges of things gives an annoying blurry look.

One simple way that might meet your needs is to go the channels palette, click on the alpha channel and then run Levels, moving the white slider all the way across the left (2 is the minimum value it can have). This will convert all the partially transparent pixels to almost fully opaque.

I know that some formats accepts alpha, and others dont, say tiff, psd, png, gif, and some others... now jpg do not accept channels at all. Under .tiff, you have to specify to save alphas... I do not know of anyway to make alphas automaticly, I do know that once you´ve done an alpha and it is saved it will be on the image, as long as u use a format wich allows that.
Now to make alphas with masks, or once you have saved it, you can alter it quite easy painting over it, meaning you can load the channel and using a hard brush erase the edges or whatever u want using black and white.
I hope I could shed some light.