why’s it so impossible to cut out a brush?

[Darby Edelen]

Sure, happy to help =)

[Boyd Hawkins]

“Once you’ve got that Alpha looking good you can use the ‘Load Channel as Selection’ button or ctrl/cmd click the channel thumbnail. Then using this selection go back to your original layer and use Layer > Layer Mask > Reveal Selection.”

I am trying to extract a person from a solid background and the hair is either not getting extracted, or some of the background is left between the strands of hair. I think the procedure you described here will will work for me, but I am new to PS and not sure what to do. I have created the duplicate channel, but I am not sure what to do now. What do you mean by getting the Alpha looking good? What do I need to do to it?

If there is another solution for what I am trying to do, please let me know. Thank, Boyd.

[Zowie Repoza]

OK, the alpha channel is what you’re going to use to cut your person out from the background, so, by looking good, wuzel meant the alpha channel needs to be as starkly black and starkly white as you can make it.

When you select the red channel that you just duplicated as an alpha, you’ll see that it’s now a black and white version of your original pic.

Go into Image/Adjustments/Levels, and you’ll get a window with a graph in the center that looks roughly like the cross section of a mountain range. Under it are three adjustment sliders, black on the left, grey in the center and white on the right.

Slide the white adjustment button to the left till the lighter areas in the picture become stark white, then slide the grey adjustment button to the right till the dark areas of the pic become stark black.

Now, once the alpha image is almost completely black and completely white (with no grey areas), click and drag this image to the bottom of the channels palette to the left most option icon, “load channel as selection.”

On the PC this can also be done by control/clicking the channel.

Go back into the layers palette, and, if your background image (the original image) is not “locked,” go into the pulldown Layers menu and choose Layer Mask/Hide Selection.

(If the background image is “locked,” you’ll see a little padlock icon on the right in its description, so just duplicate the layer to get an unlocked version, then be sure to delete the original layer, then procede as above).

All the background of the image should be removed, leaving just your figure in the foreground.

Hair is always tricky, so you’ll have to try several versions of your black’n white alpha layer as a mask to cut away only what you need from the background of the image.

[Boyd Hawkins]

Thanks! I got very close to what I wanted. There is a little of the background residue in the hair. Any suggestion on how to get rid of that? Thanks for clearing it up for me.

For anyone interested, here is a a site that also helped out a bit.

https://www.planetphotoshop.com/select-hair-by-using-channels.html

[Darby Edelen]

The ideal layer mask will have pure white in areas you want to maintain, pure black in areas you don’t and a small gradient running from white to black (mostly gray) at the edges (those small areas that are the boundaries between the black and the white).

During this whole process its important to remember you can use any filter/adjustment on a layer mask (as long as you have the layer mask and not the layer selected!) and that in a layer mask black = transparent, white = opaque, gray = semi-transparent.

First things first, it is often desirable to mask hair and other wispy elements separately from the body. So duplicate your layer and name the new duplicate something like ‘Hair’ and your old one ‘Body.’ Now hide your ‘Body’ layer so you’re just working with ‘Hair.’

You can look at Hair’s layer mask by opt/alt clicking the mask thumbnail in your layers palette. If the edges are too hard and well defined, make sure that you have the layer mask (not the layer) selected and you can use a subtle gaussian blur to feather the edges some.

Alt/opt click on the layer mask again to see what your layer is looking like.

Make sure you still have the layer mask (and not the layer) selected and you can use a levels adjustment on it to either expand or contract the white area of the mask (if you decrease your white input, the arrow on the right, it will expand, if you increase your black input, the arrow on the left, it will contract). If you have background color in your hair then you will likely want to contract the white areas of the mask.

You can do this a few times (blurring then adjusting with levels) until you have something that you like.

Once you have ‘Hair’ looking good you need to hide the portion of the body that is still showing (we want ‘Hair’ to have the hair and ‘Body’ to have the body), you can do this by painting with black in the layer mask (this will hide anything you paint on). Make sure you have the layer mask selected and use your brush tool with black as the foreground color to paint over the majority of the body. Leave all of the hair and the parts where the hair meet the head visible in the ‘Hair’ layer.

Now go back to your ‘Body’ layer and paint the hair areas of the layer mask black (hiding the messy hair with the background color in it). You only need to paint the layer mask in areas where you can see the background color showing through the hair here, if you accidentally paint too far in and part of the head disappears you can use your brush with a white foreground color to paint it back (or ctrl-z to undo).

I hope this wasn’t too much information to handle, if I didn’t give you enough detail in certain parts please let me know!

Darby Edelen
DVD Menu Artist
Left Coast Digital
Aptos, CA

[Boyd Hawkins]

Thanks Darby and Zowie for all the advice! I can tell this will work, but it will just take a lot of trial and error. I think that my first mistake was taking the picture on a light blue background instead of a white one.

Does using a green screen work in Photoshop like it does in video production? If so, I could not find the filter for it….please advise.

Thanks again!

Boyd

[Zowie Repoza]

This is a great tute, Darby. Thanx, for posting in such detail.

Definitely a keeper.

Best,
M

[Zowie Repoza]

[Boyd Hawkins] “Does using a green screen work in Photoshop like it does in video production? If so, I could not find the filter for it….please advise.”

There may be color and luminance keying options in CS2–but I ain’t found them yet.

When I have solid color background in a shot and need to isolate foreground elements, I’ve found that the keying functions of AfterEffects work pretty well.