[Gimp-user] 8 and 1 bit images

[rich404 <forums gimpusers com>]

> Hello
> I would like to save some images as both 8 bit 256 grayscale image and
> also 1 bit (2 color black and white).
> I see I can convert an image to grayscale but how do you select that
> you want to save the image as an 8 bit image. Also how do I save a 1
> bit (2 color black and white) as a 1 bit image or is it sufficient to
> save as an 8 bit image?
> Thanks

Gimp can create a 1 bit - black/white image. 

It needs to be converted to indexed mode Image -> Mode -> Indexed

Then check the 'Use black and white (1 bit) palette

You can then export the image as a gif or as a png

How to prove it is 1 bit. Imagemagick command line will give the image
properties or for a GUI XnViewMP as the screenshot.

Comparative image sizes, RGB 197k , grey 76k, 1bit 6k

rich: www.gimp-forum.net

Attachments:
* http://www.gimpusers.com/system/attachments/690/original/indexed.jpg

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