Not 100% sure what you’re asking here but hopefull the following helps.
Selection 1. Save Selection = new channel. Invert the selection (Ctrl-Shift-I). Save Selection = new channel.
Combining and subtracting channels:
Ctrl click on channel 1, Shift Ctrl click on Channel 2 will add them. Replace Shift with Alt and it subracts them.
Peace,
Tony
ooooooo-o-o-o Thank you, Tony I’m gonna try it right away!
Thank you Tony. That is very useful information but it doesn’t seem to work. I’m going to have to learn better Photoshop language so I can explain my problem more coherently.
My positive is an image within a square without the square being defined. This positive is indicated by the moving ants. It is a Saved Selection. Now I’d like to define the area around this Saved Selection. I make a new Save Selection of this area. Now I have two channels. I’d like to combine these channels and erase the first (positive) so that the negative thats left defines the image. Does this make more sense? Gosh I hope so.
Thank you
JJ
Now I’d like to define the area around this Saved Selection.
Do you mean everything BUT the previously defined selection? If so, Invert your selection (Ctrl Shift I) and it will select that.
What I’m missing?
No,everything but the previously defined selection is to large. I want to define a smaller space around the previously defined selection, then erase that previously defined selection so I’m left with a ‘negative’ of it within a newly defined space.
I’ve been doing this by making a whole new document and having to define everything over again, either adding it to the selection or subtracting it from the selection.
Gosh I’m sorry about the language problem.
Thank you for even trying, Tony
JJ
Try playing with Image > Apply Image and Image > Calculations. They enable you to combine two channels in all sorts of different ways.
Uhm… JJ.
Let’s not use the word negative and positive – it’s too confusing. Are you trying to create a selection border perhaps? Maybe you can post a before and after picture on the web somewhere and tell us the link. That way, you’ll get much better help.
Peace,
Tony
Wow, I’m confused. What are you going to do with the channels? Would turning these selection into their own layers give you what you are looking for?
Create a selection, then hit ctrl-J, This will create a new layer that contains the selection. Now hit ctrl and click on the new layer you just created, this will start the marching ants again, now invert, click down to the background again, and hit ctrl-j once again creating a second new layer. Now you have two new layers with half the background layer on each.
I’m not sure, but I think that is what you are trying to do. You can then adjust the layers sepratly.
Thank you Mark
and Thank you Tony.
I’ve been looking for a place to post an image. I’m gonna try your suggestion Mark. If that doesn’t work for what I want, and I cannot seem to express what I want to do very clearly, I’ll be back. I’ll be back at any rate.
thank you both very much for the effort,
JJ
I think tha JJ wants to create a frame like selection…
Just create the outer selection, then alt+drag inside. it will substract the new area from the selection. (if you hold the spacebar, you’re able to displace the new selection)
A good guide about selections : <
http://user.fundy.net/morris/photoshop8.shtml>
If you do want to do it with channels, Calculations or Apply image are indeed the way to go! (just create the two selections/alpha cahnnels before)
As confusing as this is, nobody really gave complete instructions for adding 2 channels together, though Tony almost did…
Maybe in spite of her apparent communication difficulties, JJ simply wants to do just that: add 2 channels.
Try this:
Control-click channel 1 in the channels palette.
Control-Alt-click channel 2 in the channels palette.
Target channel 1 in the channels palette by just clicking it.
Edit>fill>100% black.
Channel 1 is now a combination of old 1 and 2.
Thank you Pierre. That wasn’t quite what I wanted but I bookmarked it and will keep it to learn.
Thank you John, that was what I wanted to do (thank you Tony, as always, the leader). I’ve been combining channels all morning and have accomplished hours of work very quickly. I’ve added a little jiggery-pokery here and there and they are coming out splendidly.
Gentlemen Thank you all for coming to the aid of a PS user at her wits end. Someday I WILL learn Photoshopese and be able to communicate with brevity and clarity (I hope).
JJ
No problem, Jacqueline, you are welcome! I’m sure YOU can educate us on different subjects!
