If you have Photoshop it may be a lot easier to do it there.
I think the answer is no!
There I was, having my afternoon nap, when the answer suddenly came to me:
Live trace > Output to swatches.
Bingo. And they're all global too.
But that depends on how many colors you select for the live trace not
on how many colors the document contains
So you are back at square one unless you meant it you use live trace
how do I output the number of colors I select to swatches
After all a bit map image can contains millions of colors
You can get up to 256 swatches with live trace it seems.
The question would still be can you get swatches from the live trace
feature and not can you get all the colors in a bitmap image which
could number in the millions.
Am I correct? And in which case the answer is no.
Probably the best answer would be: "Up to 256 colours of your bitmap image can be turned into swatches with the live trace feature." Not all images have millions of colours. In my specific case, for instance, the bitmap is a cartoon type image with about 20 colours.
Nothing wrong with the answer it was the question which was vague as you did not describe the nature of image its limited palette and the actually specific result you need.
It is hard to read ones mind on the internet not knowing the type of wrk you do and for instance I do architectural photography and might have to Live Trace an image as well and might have to match colors or color groups but once I live trace a an image I can also use the Live Color feature to make the swatches and make them global and even make them spot colors as well as the the method you describe. I could also select all the art in the traced image and then use the add all selected to add global colors to the swatches panel.
But one has to know the nature of what you are talking about my images always have millions of colors so do most bitmap images.
See what I am saying about vagueness?