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Green screened background bled into image. Removal ideas?

Jan 31, 2014, 20:11 (This post was last modified: Jan 31, 2014 20:49 by YeeP.)
Post: #1
Green screened background bled into image. Removal ideas?
So, I am NOT a professional photographer, which is essentially where this problem comes from. Or at least the camera. That being said, I have got what I have on hand and have no choice but to use it.

We are trying to make a little art project with my daughter for her school, so my wife went and took pics of each of the kids in her class making a "heart shape" with their hands. I have the backgrounds that will go behind them all complete, so I just need to extract the hands. Well, I thought I was being smart by purchasing a green piece of fabric to put behind them, but this has almost caused more of a hassle. In the original hand picture, you cannot really see the problem, but after extracting the hands from the original, there is all kinds of green that has bled into the skin color of the kids' arms.

Does anyone have any ideas as to what could be done to help fade this green out of the arms without making them look terrible? I have 24 pair of hands that I am working on right now, so this is going to be difficult.

At the end of the day, each hand pair is going to be in about a 4.5 inch wide pic, so no where near the HUGE image that came from the camera.

Thank you!

I have uploaded a screen shot of the original and a screen shot of the one I extracted. Look at the lower side of this kids arms and you will see the green that has come in.


EDIT: Ok, so I have come to the conclusion that the kids' skin may have reflected the green fabric color. I suppose that is a camera/ photographer methods issue, but I cannot do anything about it right now. Sad


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Jan 31, 2014, 21:16
Post: #2
RE: Green screened background bled into image. Removal ideas?
(Jan 31, 2014 21:09)ofnuts Wrote:  - Sample the green cloth with a wide radius.
- Sample the skin on a forearm with a wide radius
- Select the arms (Alpha to selection)
- Add a layer under, bucket fill selection with skin tone
- Back to to layer, Colors/Color to alpha to remove the green

So where you had green you now have a skin tone.



(cut-out is a hack job)

Interesting ideas... Question on some things you said...

"Sample with a wide radius" = (guess) foreground color possibly the "brightest" skin tone on the hands, background color the darkest? Same on the cloth. Using the color picker tool...

Never done color do alpha, only alpha to selection, will research.

Did you do the cutout with the fuzzy selection tool? That is what I am doing, along with a lot of work with the free select tool.

On the alpha to selection of the arms to fill with the bucket, instead of one color, can you do an air brush with a gradient"ish" spray that is a combination of the wide radius skin tone sample you previously collected?


Thanks for the ideas!
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Jan 31, 2014, 22:25 (This post was last modified: Jan 31, 2014 22:27 by iForStyle007.)
Post: #3
RE: Green screened background bled into image. Removal ideas?
Alternatively,

Ensure the layer has an Alpha channel (Layer > Transparency > Add Layer...) will be greyed out

Choose the select by color tool Bycolorselect

Set
[v]Antialiasing on
Threshold to 23.6

-Click the tool on the bottom right section(middle of the green) & push delete.
Select > None

Now you have two options
(better preview)
Colors > Color-Balance (adjust the midtones "Magenta - Green" channel, pull towards magenta (to the left)

or

Colors > Map > Rotate Colors
Adjust the circles similar to these settings
.
(click for detailed view)
   

*If there is still a little green with "rotate colors" adjust the "To:" circle clock-wise a little bit more.

"In order to succeed, your desire for success should be greater than fear of failure." BC
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Jan 31, 2014, 22:46
Post: #4
RE: Green screened background bled into image. Removal ideas?
iForStyle007 - I have never used that color tool. It seems to be very similar to the fuzzy select in how it works, but got the job done a lot faster. What is the thought behind that tool?


I ended up using the Rotate Colors idea and I have to say that I really appreciate your help, this is awesome!

I have a couple of african american students whose skin tones take a different end result than the one I showed.

What do you recommend doing to come up with the best color range at the end of rotate? I have been trying to use the color picker to get some ideas of what I should be shooting for.

Also, I see the color rotate is set to "selection", however I have nothing selected. Would it be a good idea to try the fuzzy select or color tool to get the greenish skin areas selected before I go into the color rotate? Or maybe you are purposely not doing that so the color change is across the entire image, making it less likely to look like it was modified.


Thank you so much, I just learned two great tricks. Blush
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Jan 31, 2014, 23:15 (This post was last modified: Jan 31, 2014 23:16 by iForStyle007.)
Post: #5
RE: Green screened background bled into image. Removal ideas?
(Jan 31, 2014 22:46)YeeP Wrote:  iForStyle007 - I have never used that color tool. It seems to be very similar to the fuzzy select in how it works, but got the job done a lot faster. What is the thought behind that tool?

I ended up using the Rotate Colors idea and I have to say that I really appreciate your help, this is awesome!

I have a couple of african american students whose skin tones take a different end result than the one I showed.

To answer the above and below paragraph: For darker skin tones, the rotate tool's preview might be less subtle. Use "Colors > Color Balance" and the "Magenta ..... Green" slider. The preview is better and you have a little more control on the overall color, IMO
I haven't used rotate colors much but its good for extracting specific colors sometimes, its just that the preview is too darn small >< But you probably can also use it for darker skin tones, just rotate the "To:" circle.


Quote:What do you recommend doing to come up with the best color range at the end of rotate? I have been trying to use the color picker to get some ideas of what I should be shooting for.

Also, I see the color rotate is set to "selection", however I have nothing selected.
.
Thats the default setting, you can leave it or if you're feeling adventurous try to change it and see if it makes a difference. I just left it.

Quote: Would it be a good idea to try the fuzzy select or color tool to get the greenish skin areas selected before I go into the color rotate?

If you choose to go the fuzzy select, after you make the selection go to "Select > Shrink" and shrink it by 1 pixel, then invert & push delete, that will minimize a green halo effect. Fuzzy select isn't perfect.
"Select > Feather" after shrinking might help a little too

Quote:...Or maybe you are purposely not doing that so the color change is across the entire image

Yes, because if you shorten the radius of the second or first circle too much you start to see a line where the colors split, overall image is cleaner.

Quote:, making it less likely to look like it was modified.


Thank you so much, I just learned two great tricks. Blush
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