[Gimp-user] Image diffenernt after saving

[Silt <forums gimpusers com>]

I used the normal pencil tool at the start and for some reason that didn't made
everything white, but it messed up just at the border of the image.
Might be because I changed it from .jep to .png but I'm not sure
Now I just used the filling tool with slightly simmilar colors and it works fine
now, just a bit trouble ahaed to change all these images slightly...
Thanks for your help.

> Okay.  Then the problem is that your background color isn't a solid
> white but actually several (subtly) different shades, and even a +/-1
> difference in a pixel's RGB values may dictate whether Pivot treats it
> as opaque or transparent.
>
> How to fix it remains largely the same in concept, but the execution
> will be slightly different.  And there are several ways, depending on
> exactly what you want.
>
> For example, take the Paintbrush (or Pencil tool) and pick a fairly
> hard-edged brush shape, set GIMP's foreground color to your desired
> background color, then start painting around the background spaces of
> your image.  This will ensure that the background really IS a single
> solid RGB value and not a mix of hues or tints.
>
> This can also be somewhat automated:
>
> - Switch to the Fuzzy Select tool and on its tool options, specify a
> small threshold value (say, 8-16 range) and disable the antialiasing
> and feathering options.
> - Click somewhere in your desired background area.  This will
> highlight all contiguous regions whose color is within the threshold
> of the pixel you clicked.
> - FIll the area with a solid color (e.g. Edit > Fill with FG/BG color,
> or Paint bucket tool with "fill whole selection" option set).
>
> But automatic tools never yield a truly perfect solution -- you'll
> only get that from manual effort.
>
> By the way, since you mentioned how Pivot uses a 'chroma key' system,
> I'd recommend picking a color that is obviously not a normal part of
> the image (e.g. a pure RGB primary or secondary) and painting the
> image's background with THAT.  This will eliminate any ambiguity about
> which pixels are intended to be opaque or transparent in Pivot,
> because only your key color will be rendered transparent.
>
> -- Stratadrake
> strata_ranger hotmail com
> --------------------
> Numbers may not lie, but neither do they tell the whole truth.

-- 
Silt (via www.gimpusers.com/forums)