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R.Youden

macrumors 68020
Original poster
Apr 1, 2005
2,093
40
Hi,

Pretty new to GimpShop and I have a quick question:

I have a black and white line drawing and I want to get rid of the black background so I can put the white image into a Keynote presentation with a gradient background. Is it possible to use the rubber tool but instead of replacing black with white, replace black with nothing?

Thanks
 
(That's rubber as in eraser, right?) For an imported image, Layer->Transparency->Add Alpha Channel is probably what you are looking for.
 
Thanks, that worked well.

Thinking about it there must be an easier way to do what I want. I am pretty new to all this Photoshop stuff (hence using Gimpshop while I get into it).

As said what I want to do it take a normal black and white line drawing and turn the lines into white lines and make the background opaque. Is there an easier way to do this?
 
Under that same Layer->Transparency menu, you may have some luck with Color to Alpha… and Threshold Alpha…

For line work, you may want to first play with Image->Adjustments->Curves, and experiment with some of the other tools under that same menu, to reduce them amount of stray junk that needs to be manually cleaned up afterward (usually applies more to scans than computer painting).
 
Under that same Layer->Transparency menu, you may have some luck with Color to Alpha… and Threshold Alpha…

For line work, you may want to first play with Image->Adjustments->Curves, and experiment with some of the other tools under that same menu, to reduce them amount of stray junk that needs to be manually cleaned up afterward (usually applies more to scans than computer painting).

That is spot on! Thanks alot, you have saved me a load of time, now I can work on the content of my presentation rather than the graphics all day long! Biped walking in robots, great fun!
 
How do I install and use Gimp ? I know it's a dumb question, but I really don't know.. Do I have to install the developers tools or something?
 
How do I install and use Gimp ? I know it's a dumb question, but I really don't know.. Do I have to install the developers tools or something?

You could go that way, but luckily you don't have to!

X11 is needed, but that's pretty easy. It's one of the optional packages on your OS X install disc (there's also a download at Apple if you are still on Panther).

The Gimpshop version is a nice one to use. It's all precompiled and ready to install, so it should just work if you have X11 installed.
 
Pop in your Tiger disc, and scroll down until you see Optional Installs. Run that, and when the list of stuff shows up in the installer, look for X11 in the applications section. Check it and go on.
 
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