ghost outline

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ghost outline

rich404
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.

Attachments:
* https://www.gimpusers.com/system/attachments/1209/original/gforum.xcf

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Re: ghost outline

Rick Kline
Once you make your selection, open the Select menu, Grow..., Grow selection by 1 px, click OK

Selecting areas, especially with the Fuzzy Select Tool, Select By Color Tool, etc, often leaves a border where the pixels don’t match the selection criteria.

Let us know if that helps.

Rick
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> On Jul 7, 2019, at 8:37 PM, mauka7 <[hidden email]> wrote:
>
> 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.
>
> Attachments:
> * https://www.gimpusers.com/system/attachments/1209/original/gforum.xcf
>
> --
> mauka7 (via www.gimpusers.com/forums)
> _______________________________________________
> gimp-user-list mailing list
> List address:    [hidden email]
> List membership: https://mail.gnome.org/mailman/listinfo/gimp-user-list
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Re: ghost outline

Steve Kinney


On 7/7/19 9:22 PM, Rick Kline wrote:
> Once you make your selection, open the Select menu, Grow..., Grow selection by 1 px, click OK
>
> Selecting areas, especially with the Fuzzy Select Tool, Select By Color Tool, etc, often leaves a border where the pixels don’t match the selection criteria.
>
> Let us know if that helps.

Another method that might help:  Set the mode of the layer with the line
art to "Darken Only."  Depending on how high the contrast between the
light and dark areas of the line art, and how much brighter the layer
inder the line art is, that might give the results you need all in one
go without having to select anything.  The Brightness / Contrast tool,
or the Levels tool, can adjust the contrast in the line art layer to
make black blacker and white whiter.

Using the Erase tool on the line art layer (or, better, adding a layer
mask and painting in black to make parts of the layer 'disappear- a
reversible process) can remove unwanted bits from the line art layer, if
Darken Only mode does not remove everything you want to eliminate.


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ghost outline

rich404
In reply to this post by rich404
>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

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