Can I extract shadows from a texture to make a transparent image (png)?


Question

I have this image:

No Transparency

And I would like to extract the dark parts (shadows) to make a transparency consisting of black pixels at different alpha channel values. Here is a crude example image of what I am trying to extract:

Transparency

This way, if I put solid colors behind the image, that texture will show up over the new color and make it look nice and purdy.

I suppose another way I can ask this question is how I can turn a layer working with an "overlay" or "linear burn" blend option selected into a png consisting of black pixels at different alpha channel values.

Tough question to put in words, my apologies for any confusion.

1
9
2/16/2012 2:35:00 AM

Accepted Answer

Best bet is probably Select > Color Range. Then click a white portion of the canopy and play with the "Fuzziness" slider to get you where you want.

Once you do that click okay and your'e left with a selection. Make the selection a Mask (probably have to invert the mask afterwards). Then simply lower opacity for the layer and Save for Web.

You can save specific steps of various transparency....

20 percent 20%

40 percent 40%

60 percent 60%

80 percent 80%

100 percent 100%

7
2/15/2012 11:20:00 PM

Here's my take on it, it's a bit complicated but very effective, and can especially be used when you scan a drawing and want to take the pencil tracing from the white background in order to change the color. (Switch the Ctrl for Cmd if you are on Mac.)

  1. Make sure your image is flattened first on a white background
  2. Select all and copy (ctrl+a, ctrl+c)
  3. Go into your channels panel, make a new channel
  4. Paste into the new channel
  5. Ctrl+click on the channel thumbnail, activating the selection
  6. Go back into your layers and invert the selection (Ctrl+shift+i)
  7. Fill with desired color
  8. Delete the previously created alpha channel

This should give you a super clean result!


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