View Full Version : Using channels in Photoshop to isolate trees.

03-28-2005, 07:21 PM
Originally created in response to a question in the Tips & Tricks board, I'm posting this video tutorial link here in the Articles board at Maryam's request.

The tutorial in this video uses the blue channel as the basis for a mask that isolates some trees from a fairly clean sky background.
It generally works for busier backgrounds too. The trick is in finding the channel (or combination of channels) that extracts the contrast between the leaves and background.

This is a 33Meg Quicktime video tutorial:
http://www.jushhome.com/nick/tutorial/m ... ut_v01.mov (http://www.jushhome.com/nick/tutorial/mpo_treecut_v01.mov)

Hope this helps.
Have fun.

- Nick

04-01-2005, 04:59 AM
One more trick for the big black book. Thanks for posting this!

all ze best, englšnders.

04-04-2005, 02:53 AM
really hep man thanks..

04-05-2005, 07:41 AM
Is there any way this can transfer over to After Effects? I understand the channels in Photoshop and have been trying to do the same in AE lately.

04-05-2005, 07:45 AM
Sorry for the double post, guess I can't edit in this forum. A bit more messing around I found the 'Set Matte' effect. I think I'm on the right track now, thanks for the tutorial again!

04-23-2005, 07:20 AM
I never tried, but ja tried to save the selection, to create a canal alpha or even though to layer

05-06-2005, 05:57 PM
wow.. thanks for this link I REALLY REALLY wanted to know how to seperate trees from background. it took FOREVER to lasso it. lol

thanks again!

05-23-2005, 11:47 AM
How do you deal with this when light cast is too much like this;

05-25-2005, 12:15 PM
This technique can't recover detail lost to an overexposed area of a photo.

For this image, you could use the technique to isolate the trunk pretty well, but then you would need to use additional images and painting to fill in the detail lost in the bright areas.

04-02-2006, 01:05 PM
This can easily be acomplished with the channel mixer or background eraser tool as well. You can definately do this in after effects with a channel mixer, levels call, and a luma matte.

05-02-2006, 10:04 PM
Another great method is to use the Extract tool under the Filters option. If you practice you can get some good mattes.