I've added a stroke to a rasterised image (
Edit -> Stroke). Now, how do I select the stroke so I can copy it into a new layer and delete the current layer, leaving me with just the outline of the image?
I'm using Photoshop CC on a Mac.
There's a few ways to do this:
If you're going to use
Edit -> Stroke then you must've selected your image first. After you select it create a new layer BEFORE doing the stroke. Then you can delete or do anything else you want to the image below it.
A better way however is to use
Layer -> Layer Style -> Stroke. This will give you much more control over the stroke and afterwords you can go onto your layer panel and instead of lowering Opacity to 0%, lower the Fill to 0%. The stroke will remain at the 100% opacity while the fill within it will be reduced to 0.
If you're using shape layers initially then you can use the settings specifically for the shape vectors, but it doesn't sound like that's the case.