[GRASS-user] Output question - ps.map

[Richard Chirgwin]

Hamish wrote:
> Richard Chirgwin wrote:
>   
>> I need to produce postscript output maps with sufficient resolution
>> that when I drill down on the output image, it doesn't turn to
>> pixellation.
>>
>> I know that my input vectors are okay at high zoom levels; and I try
>> to set high region resolution using g.region. But I still have
>> low resolution outputs.
>>     
>
> ps.map in newer versions of GRASS will render rasters at the region resolution. So check "g.region -p". Beware it will happily let you make 150mb+ PostScript files which your printer may or may not strugle with.
>
> for an A4 piece of paper to get 300dpi: figuring 7" width after margins, that's 2100 x yyyy  columns x rows. I don't think there' much point going higher than 300dpi. earlier version of GRASS locked you into a max of 72(??)dpi. (or 90? can't remember)
>
> For me, I mostly ignore the 300dpi calc and for little justified reason try to keep the file size at about 25mb for an A4 plot. Looks fine.
>
> also note if you convert to PDF (I use ps2pdf13 for that) that it may reduce itself to a 72dpi JPEG, and there's not much that can be done about that, or if there is I haven't found out how. And here's an opportunity for me to plug the very handy "pdftk" command line PDF toolkit swiss-army knife software. It rocks.
>
>
> Hamish
>   
Hamish,

Would it be best to rasterise vector files at high region resolution 
before trying to get high-quality output? Or should ps.map deliver good 
results from a vector with high region resolution?

Richard
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