[vox-tech] help with gimp -- contrast of image

[Ken Bloom]

--45Z9DzgjV8m4Oswq
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

> ---ORIGINAL MESSAGE---=20
> Date: Mon, 27 Jan 2003 16:27:53 -0800
> To: vox-tech@lists.lugod.org
> From: Peter Jay Salzman <p@dirac.org>
> Subject: [vox-tech] help with gimp -- contrast of image
> Reply-To: vox-tech@lists.lugod.org
>=20
>=20
> questions:
>=20
> 1. i'm ignorant of most graphics topics.  is png a good format for this?
>    or should i be using jpeg for this?

I, too am ignorant about file types.

> 2. is there other filters that people use for this kind of thing?  i
>    have a feeling i used the wrong ones, and walking about the gimp is li=
ke
>    walking around khazad-dum.  it's huge and very unfamiliar.  help?

Your document has color in it, (in small quantities, but you'll see it
if you look at the individual channels in the curves box) and one of the
goals of your editing has to be to remove the color.

Use the threshold filter. Looking at your document on screen, I think
the threshold range from 235 to 255 (there are two blanks to fill in)
would work well.=20

Bear in mind that using the threshold filter is an excercize in making
the lines thick enough to see without introducing too many random black
dots elsewhere in the paper, and that you won't come up with anything
totally perfect, but this method works for me with a good success rate
if I'm not trying to make it look professional.

--=20
PGP/GPG Fingerprint: D5E2 8839 6ED3 3305 805C  941F 9476 A9BD E2B2 CAD1
Import with `gpg --keyserver pgp.mit.edu --recv-key E2B2CAD1`
Also on www: http://wwwcsif.cs.ucdavis.edu/~bloom/kabloom.asc
For more information about PGP and GPG, see http://www.gnupg.org/

--45Z9DzgjV8m4Oswq
Content-Type: application/pgp-signature
Content-Disposition: inline

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.0 (GNU/Linux)

iD8DBQE+NwrHlHapveKyytERAhd1AJ9DfqpvHYv1Qt1GD73YpeoTzgqV7gCglHEk
40c6nZOWso93ulo/yUgz5tc=
=r5e9
-----END PGP SIGNATURE-----

--45Z9DzgjV8m4Oswq--