[Gimp-user] ghost outline

[rich404 <forums gimpusers com>]

> Newbie here. When removing background from black and white line art,
> there remains a thin white ghost outline around the black object.
> Really shows up when a color background layer is below. Especially a
> problem as I want to use as a logo. Cannot find any tutorials on this
> except as removing foreground image in photo.

All to do with anti-aliasing. Assuming you are using Windows and Gimp 2.10

You have an alpha channel on your xcf but only one layer. Since B & W line art
assuming a colour select on the white and a delete might give something like
screenshot 1

You can mess around with the threshold value but the usual way is grow the
selection by 1 (or 2) pixel(s) to include the semi-transparent pixels before
deleting. Select menu -> Grow.  screenshot 2

With Gimp 2.10 the color 2 alpha tool Color menu -> Color to Alpha is adjustable
and should give a good result. screenshot 3

A more comprehensive description here:

https://www.gimp-forum.net/Thread-Background-removal-or-replacement-on-text-logos-and-other-computer-graphics

Attachments:
* https://www.gimpusers.com/system/attachments/1210/original/01-remove.jpg
* https://www.gimpusers.com/system/attachments/1211/original/02-remove.jpg
* https://www.gimpusers.com/system/attachments/1212/original/03-remove.jpg

-- 
rich404 (via www.gimpusers.com/forums)