Re: [Gimp-user] Change background and leave foreground

[Burnie West <west ieee org>]

On 10/26/2012 08:10 AM, Alexandre Prokoudine wrote:
> Fran,
>
> The general principle is:
>
> 1. Select objects with selection tools.
> 2. Cut and paste them to a new layer above the original layer (Ctrl+X, 
> Ctrl+Shift+V).
This doesn't work for me - it creates a new image not a new layer.

I've had more success using the free select tool doing a piecewise-linear close 
boundary around the object(s).

I usually use antialiasing with feathered edges set at radius 2 pixels, trace 
around the foreground objects (at whatever level of magnification I find most 
convenient, using the sliders on the bottom and right to focus on where I am 
working, and then (Ctrl-x, Ctrl-V, Layer->new layer to keep the image properly 
placed within the background.

If the image is complex enough to break it in pieces to separate the background, 
then don't use antialiasing or there will be cut-line residues.

> 3. Change the background layer so that the object are unaffected.
>
> There are many ways to select objects. I suggest you have a go at 
> http://docs.gimp.org/2.8/en/gimp-tool-foreground-select.html.
This process is a new one for me - it seems at first try to take as much 
detailed attention and more work. I've also tried the scissors tool but it can't 
trace around edges as well as my hand-done piecewise linear feathered edges 
approach.

  -- Burnie