Re: [Gimp-user] Seeking better "green screen" method

[Chris Mohler <cr33dog gmail com>]

On Tue, Jan 17, 2012 at 2:52 PM, Jay Smith <jay jaysmith com> wrote:
> No to "Colors-Levels....".  The problem in that operation is that it would
> also affect the related black areas in the postmarks on the stamp.  The
> color of the postmarks should not be darkened as it would change the
> appearance of the image (which are actual items that people are expecting to
> appear in the image as they are in real life).

OK - just thought I'd throw a "quick and dirty" approach out there ;)


> I agree that height/thickness is part of the problem.  Yes, we have added
> weight with no affect on most items.
>
> Please note that the "weather person standing in front of a weather map" has
> not only their own thickness, but a foot or two between them and the map.
>  If the room lighting is not 100% right, one can see a bit of "green screen
> shadow", but 99% of the time there is no shadow and no halo.  I am hoping
> that level of success can be achieved in what I am trying to do.

Ah, but camera != flatbed scanner.

If I was going to do an index replacement (aka "green screen"), I'd
use a solid background of intense color that won't be present in the
item.  Then I might:

Select the background (with fuzzy select), fill with black.  With the
selection still active, feather it (to the approx width of the "halo"
and then Colors->Desaturate.

But it's hard to come up with a workflow without seeing an example.
Can you post an example scan with a colored background and "halo"?

Chris