[GRASS-dev] Re: gis.m: how to create high-resolution graphics file ?

[Michael Barton]

D.out.png was my first script. The resolution parameter was a multiplier to
change the display geometry prior to output to a png file. It was never
completely satisfactory because of its effects on vectors, text, and display
enhancements like scalebars. These would shrink in size to become nearly
unreadable. The saved graphic file, then did not look like what you saw on
the screen.

The current display architecture no longer writes to a png file (although
ironically it uses the PNG driver). It writes to a PPM file. The save file
routine then uses gdal to translate the PPM into other formats. It looks
like it might be possible to implement the multiplier back into the output
geometry, but I'm not sure that the results are desirable.

Michael


On 5/24/06 5:04 PM, "Joel Pitt" <joel.pitt at gmail.com> wrote:

> Correct me if I'm wrong but isn't that the function of the res parameter?
> I think res=4 outputs a png at 4 times the current display size.
> 
> d.out.png --help
> Description:
>  Saves active display monitor to PNG file in home directory
> Usage:
>  d.out.png output=string [res=value]
> Parameters:
>   output   Name of PNG file
>      res   Resolution of output file (single=1, double=2, quad=4)
>            default: 2
> 
> 
> On 5/25/06, Michael Barton <michael.barton at asu.edu> wrote:
>> Moritz,
>> 
>> In terms of raster, you can only get what is in the display. That is, you
>> can't get higher resolution than you can see. This is pretty good if you
>> expand the display to your full screen, but it may not be enough for what
>> you want I suppose.
>> 
>> Under the print menubutton, you can export to eps. This is a high as it
>> gets. There is text in eps format--so it will look very good--but vectors
>> are still rendered on-screen as rasters. This is a function of the GRASS
>> display libraries/functions. It would be nice to have vectors rendered as
>> vector objects, of course, but this will take some rewriting. OTOH, this is
>> the direction we are trying to take the GUI/display architecture.
>> 
>> Michael
>> __________________________________________
>> Michael Barton, Professor of Anthropology
>> School of Human Evolution & Social Change
>> Center for Social Dynamics and Complexity
>> Arizona State University
>> 
>> phone: 480-965-6213
>> fax: 480-965-7671
>> www: http://www.public.asu.edu/~cmbarton
>> 
>> 
>>> From: Moritz Lennert <mlennert at club.worldonline.be>
>>> Date: Wed, 24 May 2006 22:54:46 +0200
>>> To: Grass Developers List <grass-dev at grass.itc.it>, Michael Barton
>>> <michael.barton at asu.edu>
>>> Subject: gis.m: how to create high-resolution graphics file ?
>>> 
>>> Hello,
>>> 
>>> I am trying to export a high resolution jpeg or ppm from the map
>>> display, but I just can't seem to find a way to do this. All I get are
>>> fairly low resolution files. Have I missed something ? How can I
>>> configure this (beyong chosing jpeg quality) ?
>>> 
>>> The same goes for printing to eps or pdf.
>>> 
>>> Moritz
>> 
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>> http://grass.itc.it/mailman/listinfo/grass-dev
>> 
> 

___________________________
Michael Barton, Professor of Anthropology
School of Human Evolution & Social Change
Center for Social Dynamics & Complexity
Arizona State University

WWW - http://www.public.asu.edu/~cmbarton
Phone: 480-965-6262
Fax: 480-965-7671