difficult selection

whelandw · #1 07-04-2005, 07:41 PM

Hi all - I have a picture with a tennis racquet and am trying to remove the background between the strings and leave the string visable. Talk about a real hair puller, this is it. If any one can give me a push in the proper direction, I would appreciate it. Want to try the OOB technique and thought this might be a good (albeit difficult) picture to surprize my long-time friend, sometime tennis partner and ex-supervisor (he retired last Friday). The 90KB file can be downloaded from http://mysite.verizon.net/~whelan/im...t_Backhand.jpg
Thanks much, Debby

Cameraken · #2 07-05-2005, 09:08 AM

I thought an OOB was something to do with Astral Travel!

Well I think this is what you are looking for. The reason you are having trouble selecting the racket strings is because they are so blurred. I Just treated the racket as a solid object to complete the picture then I added adjustment layers with a mask to change the colour of the strings to match the background.
Normally a black background is used but you loose the racket so I made it grey but you can choose any colour you want.

Ken

creeduk · #3 07-05-2005, 09:12 AM

I think you will find these 2 threads of help and interest, they deal with hair which is one of the hardest things to extract, but the technique (masking with channels) would work just as well for your problem.

http://www.retouchpro.com/forums/sho...highlight=hair
http://www.retouchpro.com/forums/sho...highlight=hair

I think I would remove everything inside the racket myself and add the strings in again by drawing them on a new layer. You could easily create these and it would be very clean. For a repeatable effect use paths then stroke the path on a new layer.

Kraellin · #4 07-05-2005, 12:38 PM

i think maybe the simplest way to do this would be to make a selection of the racket head and then simply desaturate it. the head is already black and the strings are already white, so nothing is lost but the background by desaturating.

Craig

whelandw · #5 07-05-2005, 04:15 PM

guess i will be busy for awhile trying out your idea sneaking them into my Photoshop arsenal. Thanks again, Debby

Flora · #6 07-06-2005, 12:59 AM

Hi Debbie,

I think it would be useless to put a lot of effort to change only the 'inside' of the racket leaving the rest of the green wall as is .... In this case, the 'green wall' makes most of the background so, in my opinion, it's either change the backgrund completely or leave the picture as is ....

I did change the background .... and in my second attachment I enlarged and cropped the racket to show the details ....

cspringer · #7 07-06-2005, 02:21 AM

another extraction

Duv · #8 07-06-2005, 01:36 PM

Super excellent job Flora! Have to agree with what you are saying. This gave me the chance to try Eisman's masking with Calculations. Here's what I did:

1) Made an Alpha Channel from the blue channel

2) Selected tennis player and court. I used Extraction but whatever works for you. Made background white and selection black. Black protects.

3) Back to RGB and selected inside of racket. With selection active, I inspected the channels and thought green gave me the best contrast.

4) Image: Calculations: Source 1: Channel Green Source 2: Original Alpha Channel. Blending: Screen Opacity: 100% Mask: Checked Mask Channel: Selection. Hit OK and it should give you a combination of the original mask plus the green channel mask for the strings.

5) The green channel mask shows white strings and grey background. I used Levels to increase the contrast then inverted to black strings and white background..remember black protects the selection, in this case the strings.

6) Go to Select: Load Selection

7) Back to RGB mode and drag new background onto image. Hit Mask icon at bottom.

Cheers
Dave