RetouchPRO

Go Back   RetouchPRO > Technique > Image Help
Register Blogs FAQ Site Nav Search Today's Posts Mark Forums Read


Image Help Got a problem image? Don't know where to begin? Upload images and ask our users what they think or if they can help

Isolating hair

Reply
 
Thread Tools
  #1  
Old 03-19-2012, 05:57 AM
petersweden petersweden is offline
Senior Member
 
Join Date: May 2009
Posts: 111
Isolating hair

Hi

I am working on a composite but I am struggling to make a good isolation of the hair. Attached is a crop of the hair I want to isolate and put on a dark background. A larger version is here: http://i1247.photobucket.com/albums/...r_rpro_jpg.jpg

Shouldn't this be an easy isolation? Since I want to put this on a dark background should I have selected a darker background paper when shooting in the studio?
Attached Images
File Type: jpg hair.jpg (98.9 KB, 36 views)
Reply With Quote top
  #2  
Old 03-19-2012, 06:00 AM
petersweden petersweden is offline
Senior Member
 
Join Date: May 2009
Posts: 111
Re: Isolating hair

Using refine edge with smart radius and painting along the hair I get the below result, not very impressive. What am I doing wrong?
Attached Images
File Type: jpg hair_refine_edge.jpg (99.4 KB, 31 views)
Reply With Quote top
  #3  
Old 03-19-2012, 06:02 AM
petersweden petersweden is offline
Senior Member
 
Join Date: May 2009
Posts: 111
Re: Isolating hair

I also tried using apply image on a copy of the blue channel to try to get an isolation that way, but that was also pretty bad, see attachment.

Any help is much appreciated!
Attached Images
File Type: jpg hair_layers_apply_image.jpg (99.9 KB, 30 views)
Reply With Quote top
  #4  
Old 03-19-2012, 10:27 AM
kav kav is offline
Senior Member
 
Join Date: May 2009
Posts: 574
Re: Isolating hair

Search existing threads on this. I will say this only once. There is no one step method for masking hair, and that hair isn't very clean or opaque in any given area, so it should be obvious just by looking at it that you can't just drop it into a much darker background with realistic results.
Reply With Quote top
  #5  
Old 03-19-2012, 11:10 AM
des151 des151 is offline
Senior Member
 
Join Date: Jun 2006
Posts: 222
Re: Isolating hair

See if this helps. http://www.youtube.com/watch?v=pWem0...feature=relmfu
Ray
Attached Images
File Type: jpg hair 2.jpg (87.9 KB, 78 views)

Last edited by des151; 03-19-2012 at 12:23 PM.
Reply With Quote top
  #6  
Old 03-19-2012, 02:17 PM
Chain's Avatar
Chain Chain is offline
Senior Member
 
Join Date: May 2009
Location: Oslo, Norway
Posts: 551
Unhappy Re: Isolating hair

Shooting on a background as similar as possible to what you intend to use the image on will give you the best result. Shooting on the exact opposite of what you actually need is the worst you can do (white when you need black, etc.).

If you don't know what background you will replace it with, choose a medium-light gray (as long as you have a decent contrast with the foreground).

This is because the background will spill/"bleed" into the pixels that make up the foreground; this is most problematic when the foreground is partially "transparent" like on hair. This is why you get a white fringe when you have masked the hair that was on a white background.
Think of a single pixel that has 50% colour from the hair and 50% colour from the background. Simply making it 50% transparent will just give you 25% background, 25% hair, and 50% transparent (new background).
The masking you have done so far looks fine. We just need to recolour the edges/fringes.

You can do this in many different ways. Here's a couple:
1. Use the "Decontaminate Colour" option when using Refine Mask ("mask edge").
2. Clip a new blank layer to your masked hair and use tools like clone stamp tool or a soft brush and gently paint over the affected edges. Darkening blending modes can be helpful.

For your image it will be an advantage if the new background is as light as possible, and with some texture to better conceal the poor transitions. It is very hard to make it look realistic on plain black.

Edit: The trick shown in the above post is great, but only works in some very specific cases; mainly black hair shot on white background. It won't work well on red hair or when you insert a black background.
Attached Images
File Type: jpg hair_rpro_jpg.jpg (93.0 KB, 28 views)
Reply With Quote top
  #7  
Old 03-19-2012, 02:39 PM
kav kav is offline
Senior Member
 
Join Date: May 2009
Posts: 574
Re: Isolating hair

Quote:
Originally Posted by Chain View Post
This is because the background will spill/"bleed" into the pixels that make up the foreground; this is most problematic when the foreground is partially "transparent" like on hair. This is why you get a white fringe when you have masked the hair that was on a white background.

Note how it's still got that flat lacking detail kind of look. This is what I meant when I said it takes some real adjustment. If the detail isn't there for it to stand on its own (as in fully opaque hair) then no matter how perfect the masking (and believe me, I can mask that stuff in my sleep), you will suffer these kinds of issues. They're super common. The multiply thing has been used in image editing programs practically forever. I didn't even think that was worth mentioning as it won't really do everything you need. That youtube video a couple posts up is silly because he picked something that works exceptionally well, and even then it still has breaking points.
Reply With Quote top
  #8  
Old 03-19-2012, 03:04 PM
Chain's Avatar
Chain Chain is offline
Senior Member
 
Join Date: May 2009
Location: Oslo, Norway
Posts: 551
Re: Isolating hair

Quote:
Originally Posted by kav View Post
Note how it's still got that flat lacking detail kind of look.
Yep, the highlights and such really disappear along with the light background when creating the mask. So as I said, it does not give very realistic results.

Making this look realistic would take a lot of work, and lots of adjustments. I saw there was another thread going on right now (here) that talks about different methods for masking hair. Worth checking out.
Reply With Quote top
  #9  
Old 03-19-2012, 03:36 PM
kav kav is offline
Senior Member
 
Join Date: May 2009
Posts: 574
Re: Isolating hair

Quote:
Originally Posted by Chain View Post
Yep, the highlights and such really disappear along with the light background when creating the mask. So as I said, it does not give very realistic results.
I noted this in the other thread. The OP here was lazy and didn't bother to check that one. It goes into quite a lot of detail on the same topic.

Quote:
Originally Posted by Chain View Post
Making this look realistic would take a lot of work, and lots of adjustments. I saw there was another thread going on right now (here) that talks about different methods for masking hair. Worth checking out.
I know. I posted on it. The thing is I've got plenty of ways of creating good hair results. The hardest is if you need to preserve a lot of frizz, like if it's segmented all over and you need to preserve that. There's a lot of rebuilding, drawing, adjustment layers, etc. that can go into that.

Really it's not a difficult concept, and nothing global is going to fix all of it. Most of the time when I've been asked for stuff like this, it hasn't been anywhere near perfect, so you cut out whatever you can get in a clean manner. If you need to draw any strands or flyaways, the old ones can serve as reference for direction/length and stuff. You have to get them right, but you don't want them all drawn the same. You need a steady enough hand to make smooth sweeps and stuff. Generally if people can't do it with sweeps, strokes paths aren't any better as either generally has to be refined.

I have to tell you I wish photoshop and maybe capture one had something resembling a functional linear workflow like they have in video post. Then you could use sampled values to approximate the minimum/maximum alpha values needed for newly painted hair to maintain approximate similarity. Of course it might need some adjustment on a new background given the different perceived lighting characteristics and how much might be expected to bleed through, but gamma corrected images are very annoying in terms of figuring out such values. Even if I tried to write a script for photoshop, the math in raw processing and internally within photoshop has a lot of bugs (that and I tend to make mistakes with complex scripting).

The way a lot of these programs deal with some of the complex math isn't really ideal at all. It would make more sense if the basic raster data was dumped with an associated camera native profile into a 32 bit float space with working spaces enabled in a way that resembles proofing spaces. This would give you a lot of tools in the way you work with images. Anyway I'm rambling, but you have to understand that even on a clean hair extraction you're limited by the amount of actual hair detail there so you'd make an appropriate level of adjustment to the alpha of what is left, use an adjustment layer to compensate for what the effect would be against a darker background when it comes to the combined result of hair + background influence, and even then you're limited by the amount of hair detail actually present there. It's just if photoshop worked as I wish it would, you'd have slightly more leverage. Once again... I'm jealous of the video guys in this area that have been migrating this direction for years.
Reply With Quote top
Reply

  RetouchPRO > Technique > Image Help


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Best background color for isolating hair petersweden Photo Compositing 7 09-16-2011 10:18 AM
Help! Hair needed Mike Needham Photo Retouching 2 05-19-2011 09:56 AM
Hair? julianmarsalis Photo Retouching 1 04-27-2011 09:35 AM
Anybody knows hair plug-in nebulaoperator Photo Retouching 6 02-23-2011 06:58 AM
wind blown hair Veralisa Image Help 5 12-11-2010 12:27 PM


All times are GMT -6. The time now is 02:47 AM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
SEO by vBSEO ©2011, Crawlability, Inc.
Copyright © 2016 Doug Nelson. All Rights Reserved