Re: [Gimp-user] Replace Gold Splotches

[Steve Kinney <admin pilobilus net>]

On 11/16/2016 01:21 PM, Liam R. E. Quin wrote:
> On Wed, 2016-11-16 at 17:44 +0100, lanierprintables wrote:
> > Can someone tell me if/how I can use Gimp to replace the goldish
> > splotches with
> > my own pattern?
>
> One way might be to use select by colour (shift-O) on the gold until
> you have all of it. You might need to deselect the human outline on the
> left. To do that,
> (1) in tool options, with select-by-colour active, reduce the threshold
> probably to 1 or 2
> (2) hold control down and click in that outline, on one of the whitish
> lines.
> This may leave 1-pixel holes in the selection of the gold. That's OK,
> grow your selection by 1 pixel. select->grow.
>
> Now feather the selection by 1 pixel (select->feather) to blur the
> edges slightly.
>
> Now, if you have your patten as a layer in the image below the main
> part, edit->cut will make holes in the top layer and you'll see through
> to the pattern. If it just makes the gold solid background colour,
> undo, show the layers dock (control-l), right-click on the layer's name
> and "add alpha channel" which is gimp-jargon for "allow transparency on
> this layer". Then do the cut again.
>
> An alternative is to use the bucket fill tool and fill with pattern.
> You can have the pattern open as anothe image and do edit->select all
> (control-a) and then edit->copy (control-c), and then go back to the
> main image and one of the patterns in the Tool Options dock for the
> bucket fill tool will be the clipboard.

Another alternative, a bit more complicated but possibly worth it if you
have to make adjustments to your selection, or tweak the pattern
independently of the rest of the image, is to use a layer mask:

Put your pattern on a layer of its own, put your image on a layer above
that, and add a layer mask to the top layer (your original image).
Right click the top layer in the Layers dock, select Add Layer Mask,
accept the white / full opacity default.


Select the gold regions as above, then add a mask to the layer:  Right
click the top layer in the Layers dock, select Add Layer Mask, accept
the default White option in the dialog that opens, and hit OK.

Then drag and drop black from your color selector to the canvas to make
the selected areas of your image layer transparent.  The pattern on the
layer below your image will show through "holes" created in the original
image by the black parts of its layer mask.  Now you can dismiss your
complex selection, and make adjustments to the mask as necessary.  For
instance, if you see a gold fringe around the edges of your "deleted"
regions, you can do Filters > Generic > Erode to expand the black
regions on the mask, removing the fringe.

This method is non-destructive; you can "bring back" bits of the
original image layer by painting with white on its mask, or eliminate
bits of the original image layer by painting with white on the mask. In
the case at hand that may not be necessary, but being able to adjust the
edges of "deleted" regions comes in handy quite often.  This method also
enables you to adjust the brightness, color, etc. of the pattern layer
independent of the original image layer, change it to a different one
or etc., without having to leave your complex selection in place through
subsequent editing processes.

:o)