Hello, thanks you very much for the answers, that helped _a_ _lot_ !
Lowering the latitude from 90.0 helped, now i can render the whole world. I can now render a map of the world and i'm trying to scale certain parameters so a printed map will look fine. Best regards, Torsten. Am Samstag, 18. April 2009 10:34:06 schrieb D Tucny: > 2009/4/18 Torsten Mohr <[email protected]> > > > Hello, > > > > i installed PostgreSQL / PostGIS and use a modified version of this > > script to render maps: > > > > svn.openstreetmap.org/applications/render/mapnik/generate_image.py > > > > I've just created two maps of Germany, one is 12000 x 16000, the other > > is 3000 x 4000. I then get two different 'levels of detail', as > > expected. > > > > I'd like to print a map of Germany as a poster. My understanding is that > > osm.xml is configured to create maps that look fine on a screen. > > But the Pixels per Inch on a computer monitor are different compared to > > the PPI on a printed poster. > > So e.g. text size, symbol size and others may not look optimal when > > printed. > > > > Has anybody got any experience with changing osm.xml to create maps > > that look fine when printed (readable text, ...)? > > > > Or do i worry too much and printing PNGs looks just all right? > > A standard/typical print resolution is 300dpi, whereas a standard/typical > screen resolution would be 96 dpi... So, if you had an image, viewed at > native resolution, on a screen that took up an area 30cm by 30cm and looked > good, to print it at it's native resolution the image would be 10cm by 10cm > (approximately)... Your 12000 x 16000 image would be good for printing > about 1m by 1.3m at 300dpi, any smaller and you would loose some of that > resolution, any bigger and the image would start to appear pixelated... > Your 3000 x 4000 image would be good for up to 25cm by 34cm at 300dpi... > > If you wanted to print an A0 poster, with no margins, you have a print area > of 118.9cm by 84.1cm, so, an optimum resolution for your image would be > 14043 x 9933 if printing at 300dpi... If you view this image at 33% scale > on your computer, you'll get a rough idea of the size of features when > printed (though you may want to work out the real DPI of your screen if you > want it to be more accurate, e.g. the screen I'm using now is 37.6cm wide > with a horizontal resolution of 1280 pixels, or 86dpi, so I'd get more > accurate feel of size by using a scale of 29% when viewing the image on > screen)... > > The maps are typically rendered for viewing on a screen, so, text and > symbols may appear too small when printed, you would likely need to adjust > their size for print, but, how much you adjust it can be a taste thing... > > I haven't done it with a map myself, but others have and hopefully they > will be able to contribute here with their experiences... > > 2. > > > When rendering the whole world with coordinates like this: > > > > # unused: ll = (4.5, 46, 16, 56) # Germany > > ll = (-180.0, -90.0, 180.0, 90.0) # World > > > > Then i just get an empty file (just background). > > > > Is this related to the scale denominators in osm.xml? > > It likely is a combination of the scale and potentially a lack of the coast > shapefiles... The lowest level of detail just has the coast line rendered > from the shapefiles... > > > Can anybody give me a hint on what values to use when printing > > the whole planet? > > To give accurate values, people would need to know what size image you will > be looking to create, so, would need to know the size and resolution you > will be printing at... > > Hope that helps... > > d _______________________________________________ talk mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk
