Help on ps.map ?

Malcolm Williamson malcolm at cast.uark.edu
Mon May 22 08:00:00 EDT 1995


I believe that this problem was fixed in Update 4 (GRASS 4.1.4). The 
following is a quote from the UPDATES.5 file:
-------
  3. increased the maximum number of pixels allowed on a page in 
function
      map_setup.c : 
          limit = 300000000L; 
     if the total number of pixels is larger than "limit" then ps.map 
     reduces it to limit
     This change allows us to print layers at their actual resolution.
     For example: an AVHRR layer at 151 cells per inch. 
 
     NOTE: we are thinking about assigning different upper limits to 
different 
     Postscript devices, as an additional parameter in the ps.devices 
files.
 
(lines deleted) 
STATUS:
    FIXED  with update package 4
---------

On 20 May 1995, Jens Bitter 
wrote:

> Hi !
> 
> do you can help us ?
> 
> We have following problem with the ps.map output. The background raster map
> is a city plan of Frankfurt / Germany (scanned with 300 dpi resolution).
> In ps.select we use a effective resolution of 400 (dpi ?) and a papersize
> equal to the size of the scanned map. In g.region we select the whole area
> of the raster map (8000 columns x 10000 rows).
> 
> As first try, we want to have a 1:1 copy on our postscript printer (300 dpi
> resolution). To our really surprise we can hardly read the city names. It
> seems to be that only every third pixel will be printed and an advise for
> this obvious behaviour is the file size of the ps output.
> If we zoom in the region, the output quality will be better. Off course,
> all other parameters are the same, no scaling and so, but the rows and
> columns changes, depending on the choosen region.
> 
> The resolution for the ps-output sems to depended on the number of the column
s.
> For example: columns=800 good quality, columns=2000 medium quality,
> col=8000 bad quality. (Quality is : how good we can read the street names)
> 
> Maybe the programm looks for the number of columns and scales down
> from given levels on ?
> 
> Do you have an idea what happen's ??
> 
> Many thanks !!
> 
> bye Jens and Alex
> 
> --
> work : currently not available
> home : jens at zaphood.tng.oche.de          Jens Bitter, Beeckstr. 9
> PR   : DB4KH at DK0MWX                      52062 Aachen, Germany
> 
> Please look for my new sub.domain tng.oche.de !!!
> ## CrossPoint v3.02 ##
> 





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