How to remove horizontal lines in Output

[Matei Georgescu]

hi Arlindo,

Does your solution also apply to V1.94b or do i have to grab a newer
version?

thanks,
matei

On Fri, 17 Jul 2009, Arlindo da Silva wrote:

> On Fri, Jul 17, 2009 at 3:17 AM, Dhaval Prajapati <
> dhaval.prajapati at iccsir.org> wrote:
>
> >  Hi,
> >
> > I have prepared  . ps files using grads. Now in the file there are
> > horizontal lines coming for colors
> > How to remove it?
> > is there any command to get batter images?
> > I am attaching one file for sample in both .ps and .jpg format
> >
>
>
> Try "gxyat" that comes with the opengrads bundle (available from
> http://opengrads.org). Basically, gxyat is a replacement for "printim",
> although it can produce .ps, .pdf and .svg output. More info here:
>
>      http://opengrads.org/wiki/index.php?title=Gxyat
>
> Some remarks on these "lines":
>
> 1) The "lines" you are referring do not appear if you print your postscript
> file on paper, only on the screen.  These "lines" come from an artifact of
> the grads shading algorithm and the anti-aliasing algorithm used by the
> programs that display postscript on the screen.  However, depending on your
> display program, sometimes you can turn anti-aliasing off and the lines go
> way. However, the fonts do not look as good.
>
> 2) When you convert your postscript to jpg, anti-aliasing is usually applied
> and you get the "lines". Again, depending on your conversion program you can
> turn anti-aliasing off and get rid of the "lines" at the expense of jagged
> fonts.
>
> 3) What "gxyat" does when creating image files (.png in this case) is to use
> anti-aliasing when drawing lines and turn anti-aliasing off when doing
> polygon fills. In the end you get smooth fonts and no "lines". In addition,
> "gxyat" gives you a lot more flexibility with transparency.
>
> 4) If you write .ps/.pdf files with gxyat you will have the same problem
> with the "lines". The reason is that there is no way (that I know of) in
> postscript to turn anti-aliasing on/off for part of a page, it is all or
> nothing.
>
> BTW, you can use "gxyat" from the grads command line (replacement for
> "printim"):
>
> ga-> gxyat image.png
>
> or from the OS command line (replacement for gxpng, gxeps):
>
> $ gxyat -o image.png image.gmf
>
> where "image.gmf" is a grads metafile.  The SVG output is very useful to
> import grads output into vector graphics programs such as Adobe Illustrator
> or Inkscape without loosing any resolution (great for posters).
>
> It would be great if someone could contribute a recipe to the Cookbooks
> illustrating these points.
>
>    Arlindo
>
>
> --
> Arlindo da Silva
> dasilva at alum.mit.edu
>

-----
Matei ("Matt") Georgescu
Post-doctoral Fellow
Program on Food Security and the Environment
Stanford University
Y2E2 Bldg - MC4205
473 Via Ortega
Stanford, CA 94305
homepage - http://stanford.edu/~mateig