How to extract a blended layer from its background

Question

I often get PSD assets that have layers with blending modes that end up blending them into a background layer. I'm trying to figure out of there is any way to cleanly extract these layers from the background, ending up with a transparent background, but keeping the color effects that were created by blending onto, say, a blue background?

Hopefully that's clear...

A very simplified example:

• blue background
• take a white brush and paint a line on a higher layer
• set this layer to Overlay
• You end up with a light-blue streak with blurred edges.
• I ultimately want an image that has this same light-blue color but blends to transparent instead of blue.

Obviously real-life examples are much more complicated, but hopefully this explains what I'm trying to do :)

Answer 1

• Blue background
• New layer with white squiggle
• Set blend mode to overlay
• Select > Color Range, click on white squiggle and adjust fuzziness.
• Use quick mask to clean up as required
• Duplicate layer to move the squiggle into a layer with transparent background

Or use select color range, select the background, quick mask, then delete to remove background.

The other thing you could try is duplicate your background layer, move it to the top, and set blend mode to subtract or difference. You'll get a black background with the "white" squiggle, but the squiggle will be a bit darker too.

Answer 2

If I understand the question correctly, you want the resulting color appearance and the shape with that color appearance to become a layer, with the (previously blended) color now a full "native" color and the remainder of the layer transparent.

Here's how I would tackle it, given this as a starting point (your example):

• First create a new layer that duplicates the color appearance of the current composite. You do this by targeting the current top layer, then using Ctl-Alt-Shift-E (Cmd-Opt-Shift-E) to create a new layer. This basically creates a new layer and applies "Merge Visible" into the new layer.

• Ctl/Cmd-click on the layer thumbnail of your blended layer to create a selection. (Don't target the layer, just Ctl/Cmd-click the thumbnail in the layers panel.)

• The new solid layer should still be targeted in the layers panel. Press Ctl/Cmd-J to copy that portion of the solid layer onto its own layer.

Answer 3

I did this:

• Blue background
• New layer with white squiggle
• Set blend to color dodge (overlay didn't do much for me)
• Cmd+Click (Mac) on the squiggle Layer icon to select the luminance
• Double click the background layer and turn it into a normal layer
• Add layer mask on that layer

That should do it.