[GRASS-user] dpi output from ps.map

[Hamish]

Tom wrote:
> Have you tried it?  I believe that hard-coded limit was taken out years
> ago. (as I recall, I may even have been the person who complained
> about it on this list, as I had a big raster I needed to render on a
> large-format printer, and this hard-coded limit was in the way.)
> 
> In fact, I'm pretty sure that this limitation is long gone.  Look at the 
> documentation for a current version of ps.map, and it'll tell you that
> raster resolution is controlled by the region settings.

Indeed it is long gone many releases ago. AFAIK the limit was 300M cells
for greyscale and 100M cells for RGB rasters.

as others have mentioned, defeating default ghostscript options often
solves the 72dpi PDF hardcopy problem. See:
  http://grass.osgeo.org/wiki/Ps.map_scripts#Converting_PostScript_to_PDF

  ps2pdf -dPDFSETTINGS=/prepress -r1200 filename.ps

(72dpi is usually fine for the screen or for projector presentations, but
not the printed page)



and from the ps.map man page:

       The  resolution  and  extent of raster maps plotted with ps.map
       are controlled by the current region settings via the  g.region
       module. The output filesize is largely a function of the region
       resolution, so special care should be  taken  if  working  with
       large raster datasets. For example if the desired output is US-
       Letter sized paper at 300dpi, with 1" margins  and  the  raster
       filling  the  entire  page, the usable area on the page will be
       6.5" x 9", which at 300 dots/inch is equivalent to a region  of
       1950  columns x 2700 rows (see "g.region -p"). Any higher reso-
       lution settings will make the output file larger,  but  with  a
       consumer printer you probably won't be able to resolve any bet-
       ter detail in the hardcopy.



regards,
Hamish