How to convert grayscale to monochrome?
Karl S
I must be missing something very obvious, but converting a grayscale
image to monochrome b/w has escaped my grasp.
Karl S.
Doctor J. Frink
Unless things were much different back then you need to go to
Image>Mode>Indexed and choose "Black and White (1bit) Palette".
Frink
--
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anything grayscaled BACK to anything colorized...
even mono-chromatic ?
Maybe I've missed the point :).
I have been fooled a few times, getting Sepia
looking results instead of true grayscale.
Karl S
> On Mon, 13 Mar 2006 21:00:33 -0800, Karl S <ka...@sysmatrix.munged.net> wrote:
>
>>I have an older version, Gimp 1.2.5 provided with Mandrake 10.1 linux.
>>I must be missing something very obvious, but converting a grayscale
>>image to monochrome b/w has escaped my grasp.
>
>
> Unless things were much different back then you need to go to
> Image>Mode>Indexed and choose "Black and White (1bit) Palette".
>
> Frink
>
Found that "Indexed" was grayed-out. the image I was playing with is an
indexed GIF from an online comic called "Freefall". I was going to play
around with the flood-fill, but flood-filling grayscale images usually
results in those annoying unfilled dots around the edges.
Hmmm... Maybe it's a GIF thing... Maybe if I converted the file to a PNG
or TIF or something...
Karl S.
Karl S
Bad habit of mine.
Doctor J. Frink
>Doctor J. Frink wrote:
>> Unless things were much different back then you need to go to
>> Image>Mode>Indexed and choose "Black and White (1bit) Palette".
>>
>That's where the head-scratching started... I'd tried Image > Mode...
>Found that "Indexed" was grayed-out. the image I was playing with is an
>indexed GIF from an online comic called "Freefall". I was going to play
>around with the flood-fill, but flood-filling grayscale images usually
>results in those annoying unfilled dots around the edges.
Ahh, the image is alread in an indexed mode.
What I would do is
Image > Mode > RGB
then
Image > Mode > Indexed
Sorry about that. It's easy to forget that indexed images can't be
reindexed directly (that I know of).
If you want to flood fill with colours then you'll want to go back to
RGB once you have a B/W picture you're happy with.
Henning Makholm
> the image I was playing with is an indexed GIF from an online comic
> called "Freefall".
Well, there in particular you have the problem that Freefall usually
contains not only black and white but also flat grey areas - and
occasionally, as in the current boat sequence, also grey _lines_.
Narrowing the image down to _three_ colors such that the solid greys
stay grey _without_ leaving a scattering of grey pixels at the
antialiased black-white boundaries is a hard problem.
> I was going to play around with the flood-fill, but flood-filling
> grayscale images usually results in those annoying unfilled dots
> around the edges.
It's not the greyscale per se, but the anti-aliasing that creates the
problem. If you're trying to color the strip, one technique I have
occasionally found useful is:
1. Convert to greyscale.
2. Use the levels/curves tool to whiten out all but the blackest of
pixels. The inking in Freefall should be bold enough that you can
do this without the lines breaking up (otherwise you need to fill
in the missing pieces with a 1x1 pencil, but don't worry about
lettering and other lines that you don't need as fill boundaries).
The result is not pretty but is floodable.
3. Make an upper layer that is black all over, and use an inverted
version of the _original_ grayscale image as a layer mask. Thus
the layer supplies the _black_ part of the original image and is
transparent where the strip is white.
4. Convert to RGB and fill in colors and shadows according to your
artistic skill in the _lower_ layer. If you're really creative, you
can paintbrush highlights and lens flares in a transparent layer
_above_ the line art layer.
5. Put an all-white layer _below_ the color layer.
6. Using the color select tool, select and kill all _black_ pixels
in the color layer. They were the pixels you used only as floodfill
boundaries; since they now become white you will be able to see
if there are leaks near thin lines where you need to extend the
colored areas of the color layer by hand in high-magnified mode.
--
Henning Makholm "I ... I have to return some videos."