Photo Compositing - - Help making a selection

unnamedplayer · #1 10-04-2005, 02:23 PM

Hi all, I was hoping someone could help me with this image I have attached. I want to select just the palm trees so that I can make a silhouette out of them. I was hoping someone could suggest the best way to go about this task. Any help is greatly appreciated!

Cameraken · #2 10-04-2005, 07:49 PM

Hi No name Welcome to RP

Wow! You picked a tough one.

Because the tree and the background are similar colours this makes the selection more of a guess.

What program are you using?
Does it have to be this tree?

I have found another tree at stock exchange which is easier because there is a good separation of colour between the tree and the background

There are some tutorials here

http://retouchpro.com/tutorials/?m=show&id=27

http://retouchpro.com/tutorials/?m=show&id=20

http://retouchpro.com/tutorials/?m=show&id=120

If you are using Photoshop then you can also try Filter>Extract

But if you try these tutorials on your picture and on mine you will see how difficult your picture is.

In my example I just selected the blue channel, adjusted the levels and cropped.
This gave me a silhouette similar to what you want.

Ken

unnamedplayer · #3 10-04-2005, 08:22 PM

Hi, thanks for the reply. Sorry I forgot to mention I am using Photoshop CS and tried to make the selection by copying one of the alpha channels and adjusting the levels as you mentioned and ran into all of the problems that you mentioned too! That's why I was hoping for some input about how to go about this. I picked this picture because I like the position of the trees in the shot and thought that their silhouettes would work well in the logo I am trying to make.

I'll look into those tutorials you posted as well. Please keep the advice coming!

Kraellin · #4 10-04-2005, 10:42 PM

being inherently lazy, i didnt look at the links that cameraken pointed out. i do recall one that fits very closely to your image, however. it's in the retouch, restoration forum and dealt with hair. yup. similar sort of problem. you cant just select out the whole thing based on brightness because of all the other similars and you cant pick it up with hue/color or rgb, at least not all of it at once. this is due to bleeding from the background onto the trees. so if you try to pick up the green/black trees, you'll miss parts because they are now blue from the sky. these are a real headache, at least for me. you can try to change the background, but there's no simple, one step way to do that either because of the variances.

so basically, if you really want these particular trees and you really want a good copy, i'm thinking you're going to have to get in close and do some hand work.

i did have some limited success with 'hue map' in psp 10. i simply bulk changed hue ranges to different colors than the trees. i think i recall that flora used the hue/sat/light adjustment layer also on something like this. so, that might work also.

also, did you want the trees completely selected out as new images or layers, and did you want them as separate from each other, or did you want them in the same relative positions and both in the same image?

i could do the work on this one, but it would slow down commensurate with detail desired.

Craig

philbach · #5 10-05-2005, 05:52 AM

A technique I learned here via a html reference to Click for Website Russel Brown's web site (advanced masking quicktime tutorial) uses Channel mixer adjustment layers to separate one area from the other. He then uses alpha channels and adds them. Its a great tutorial for this type of problem. The selection enclosed was done using this technique.

Ken Rogers · #6 10-05-2005, 11:03 AM

That is a fantastic idea! That's one more trick to put in my tool bag!

Kenny

unnamedplayer · #7 10-05-2005, 07:27 PM

Hi again all. Thanks for all the help! This is what I got using the Advanced Masking tutorial by Russel Brown. This was quick and dirty just to see what it could look like so it could probably be tidied up some. Let me know what you guys think and if you have any other suggestions about how to go about this. Thanks!

philbach · #8 10-06-2005, 03:06 AM

Well Unamed Player, the selection looks good. Invert your picture and place it in the channels palette and your good to go.

Gary Richardson · #9 10-06-2005, 09:34 AM

Hi Unnamed Player,

Nice job considering the difficult background.

The left hand tree is showing the shoreline behind it, if you can enlarge, it may be possible to remove it with some careful hand work. (Not possible with posted image (I tried)).

If you're using it as a mask, it may not be a problem, if you're using as a silhouette, it catches the eye.

You could try taking the leaf above on the RHS of the LH tree, and moving it to replace the lower leaf. (Very quick try with this attached, no use to you as a mask, but loses the shorline on the lower leafs if used as silhouette).

Gary.