[Gimp-user] 8 and 1 bit images

[jgarnold <forums gimpusers com>]

> Well, heed your experts advice.
>
> A couple of points, that you might already know.
>
> The 'paint tools' have their own opacity setting. No need for a 25%
> brush.
>
> The Paint Tool introduces anti-aliasing at the edge. For the 1 bit
> indexed image the anti-aliasing is 'lost'. Otherwise for 'hard' edges
> use the pencil tool.
>
> Exporting as a tiff is not a problem, Use Mode -> Greyscale for 8 bit
> and
>
> remove any alpha channel, then Mode -> Indexed -> black and white (1
> bit) for that mask.
>
> rich: www.gimp-forum.net

Thanks for the extra information.
The reason I use a '25% hardness' paint brush near the edge is so that the
background satellite imagery will BLEND into the default Flight Simulator
scenery instead of having a hard edge. Well that is what I have been told on a
flight simulator scenery developers forum and also read in tutorials. With a
blend mask the white area allows the background satellite image to fully show
through and black does not allow it to show through. Every shade of grey in
between allows slightly less of the satellite background image to show through.
This results in the satellite imagery to blend with the standard scenery and not
have a hard line along the edge. Hope I have explained properly. Like the
attached blend mask (taken from a video tutorial). Note the 'shading'
If there is a better method to produce a grey scale between the white and the
black please advise.

Attachments:
* http://www.gimpusers.com/system/attachments/698/original/blend_mask.jpg

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