problems with Photoshop Alpha Channels

Hi all



Got a job where I want to use alpha channels to cut-out some images in Photoshop and then put them into an ID frame with a black background. Want to use alpha channels rather than a clipping path as I need the edges to be feathered (have applied 2 pixels of feathering to the selection in Photoshop before saving it).



When I do this and drop it into Quark it looks good but when these images are dropped into ID and then the alpha channel is turned on, with the default Threshold and Tolerance settings, it doesn't look good. It looks like a rough approximation of my alpha channel, all the fiddly bits and bezier curves in the selection have been smoothed out and the feathering has gone. Playing with the settings doesn't really seems to help either. If I turn on the alpha channel in the import options when importing then it comes in as expected but I have quite a few images already in the document that I need to turn on the alpha channels for.



Both PS and ID are CS3. I've tried saving the images both as PSD and tif. Anyone got any ideas? Seems odd that when I import an image with the channel on I can't go to the clipping options and tweak the settings.



thanks,

Iain
problems with Photoshop Alpha Channels
Do you have high quality display enabled?



Bob
problems with Photoshop Alpha Channels
Yes (sorry, meant to say that).

Wait a minute...you're using the alpha channel as a clipping path? Why?



Clipping paths are hard edged, not feathered. Just save the PSD with a

transparent background and place that.



Bob

Thanks for your reply Bob. I've confused things with my terminology I think. We're drawing a path round the image, using bezier curves where appropriate, making that work path a selection (feathering the edge in the process) and then saving the selection (as an alpha channel) and then using the feathered alpha channel in Quark/ID to knock-out the background. Not keen on using a PSD with a transparent background at the moment as these are just test files while we show the customer what it will look like if we do cut-outs. We are making a couple of different alpha channels per image, with different settings, which would mean multiple files if we used your method I think. Maybe once we get the approval from the customer we could use PSDs as you describe but I was just wondering why the options for affecting alpha channels after importing the image aren't working as I expected.



Iain

If you want a feathered edge you can't use a clipping path.



It sounds to me like you're still stuck using Quark methods. That's like

trying to fit Chevy parts in a Honda.



Bob

It's not really a clipping path, it's an alpha channel and it does work as expected *providing you turn on the alpha channel during the import process*. But what I wanted to know was how can I 'turn on' an alpha channel in a series of images that are already on the page without it making a pig's ear of it.

%26gt;That's like trying to fit Chevy parts in a Honda.%26lt;br /%26gt;%26lt;br /%26gt;No, he gave a Honda part number:%26lt;br /%26gt;%26lt;br /%26gt;A selection made from a clipping path is just a selection like any other.%26lt;br /%26gt;%26lt;br /%26gt;It seems as though you just want to bash Chevy. %26lt;G%26gt;%26lt;br /%26gt;%26lt;br /%26gt;Al
He's trying to get a clipping path to behave like an feathered selection.



Bob

That's not really the issue. My selection started as a path, yes, but is a feathered alpha channel long before it gets to ID. My question was why does the post-import alpha channel options make the it look so bad.



Anyway, Honda's always work. Everyone knows that!

Because your treating it as a clipping path.



Do yourself a favor and hit F1 and search for alpha channel.



Bob

Yes, I suppose that's what it is saying - accessing your alpha channel through the Object%26gt;Clipping Path menu means it will get treated like a clipping path. Okay then - the question I should have asked - is there any way to turn on teh alpha channel once it has been imported *and keep it treated as an alpha channel? I suspect I know the answer to this one!

Read post three.



Bob

With respect that doesn't really answer my question and in post 4 I say why I'd rather not use that method for this particular task. Although I appreciate it does work, it doesn't help me in my current predicament. If I can't make the existing imported pics work I'll just reimport them with the alpha channel turned on (which will work as expected) rather than have to go back to Photoshop and then have to reimport them or update them.



Thank you anyway.

You can access the alpha channels by selecting the link in the links panel and choosing re-link. You'll need to check the show import options box -- at least on my system holding the shift key while you say OK doesn't seem to be invoking the options dialog.



Peter

Thanks for your reply Peter, that sounds like a good workaround. Unfortunately the Show Options checkbox is greyed out when I try to relink a file, even if the box was checked last time I imported something. Any thoughts?



Iain

What format are you saving the images in?

Peter - the box is greyed out when trying to relink both PSD and tif files.

What about when you try to place a new file?



You might want to try backing up your ID preferences and letting ID generate a fresh set to see if that helps.

Trashing the preferences did it. Thanks Peter.

welcome.