stripes in eps output

[Matthias Munnich]

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The trouble is that one of the most common PostScript renderers,
Ghostscript (gs), is nowadays doing antialiasing by default to soften
ragged lines and corners.  It blends neighboring bit even for purely
horizontal lines.  This leads to the pixel-width horizontal lines due
to the way Grads is filling contours.   Antialiasing can be turned of
with "-dGraphicsAlphaBits=1" in gs or "-noantialias" in ghostview

 I still don't  believe that hardcopy publications are likely to show
lines.  These lines would be close to invisible anyway  on a 1200dpi
printer .   I  suspect people are rendering  their graphics themselves
with tools like ImageMagick.  Almost any free software is  using
Ghostscript as the rendering engine.  These tools usually use default
Ghostscript settings and you get the lines.

Well, Jennifer's email suggests otherwise.   Unfortunately  you do not
control how the graphic is rendered in print and submitting a rendered
figure as suggested by Jennifer and Jeff is one solution.  However,
you loose print quality.

My approach would be to look through a recent issues of JGR and see if
the figures show these lines.   I always recognize grads plots -- I
guess I stared at too many by now.   I am pretty sure it's fine to
submit gxeps created EPS files to JGR.   There were no lines in the
figures of my recent GRL paper.


... Matt



Jennifer Adams wrote:
> Alan et al., Those horizontal stripes in the ps/eps output are a
> real nuisance. Potential sources of the problem start with the
> contouring algorithm in the GrADS graphics layer, but the presence
> of the stripes also seem to be influenced by gxps, gxeps, any
> external or internal utility that converts the .eps or .ps files to
> something else as they get incorporated into written documents, and
> the printers used by scientists and publishers also seem to be a
> factor. My recent experience is that it's nearly impossible to
> predict whether you'll get stripes or not. It's seems more likely
> that you'll have stripes than no stripes, and the stripes also seem
> to be most garish in plots with shaded contours and white space.
>
> Here at COLA, we've begun using image format files (.png and .gif)
> instead of vector graphic formats, simply because they're more
> reliable even though they don't always look as good.
>
> COLA users are being weaned from using PCs running MS Windows, but
> my sense is that the gv32 program allowed for conversion of GrADS
> metafiles into something else that did not have stripes. I can't
> verify that, perhaps the windows users out there can confirm or
> deny.
>
> Brian is planning to rework the contouring algorithm, so there's
> hope for the future; unfortunately, that hope doesn't help in the
> short term. I would see if you can get the publisher to provide a
> test print of your figures, and if that looks bad, see if you can
> use an image format instead. A .png at 850x1100 resolution, shrunk
> down to journal size, might not look so bad.
>
> Jennifer
>
>
>
> On Feb 8, 2007, at 11:03 AM, Alan Robock wrote:
>
>> Dear Friends,
>>
>> Has anyone found a solution to the age-old problem of horizontal
>> lines between bands of color in shaded grads output?  We have eps
>> files to submit for an accepted JGR paper and are concerned about
>> how the final version will look.
>>
>> Is there anything we can do to the files before we submit them to
>> fix the problem?
>>
>> Alan
>>
>> Alan Robock, Professor II Department of Environmental Sciences
>> Phone: +1-732-932-9478 Rutgers University
>> Fax: +1-732-932-8644 14 College Farm Road
>> E-mail: robock at envsci.rutgers.edu
>> <mailto:robock at envsci.rutgers.edu> New Brunswick, NJ 08901-8551
>> USA http://envsci.rutgers.edu/~robock
>>
>
> -- Jennifer M. Adams IGES/COLA 4041 Powder Mill Road, Suite 302
> Calverton, MD 20705 jma at cola.iges.org <mailto:jma at cola.iges.org>
>
>
>


- --
- --------------------------------
Matthias Munnich
Univ. of California, Los Angeles
Dept. of Atmos. and Oceanic Sc. and
Inst. of Geophysics and Planetary Physics
3845 Slichter Hall
Los Angeles, CA 90095-1567
Phone: +1-310-794 5899
Fax: +1-310-206 3051
Email: munnich at atmos.ucla.edu
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