Re: [OSM-talk] rendering some large maps, e.g. whole world
Holger, Great script for modifying mapnik symbology for higher/print resolution, and awesome to hear that you are using Cascadenik. Just a note that I've started to work in Mapnik core for supporting scaling based on variable resolution output: http://trac.mapnik.org/ticket/343 - Dane On Apr 18, 2009, at 3:18 AM, Holger Schöner wrote: Hello, 2009/4/18 Torsten Mohr tm...@s.netic.de 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. That is correct. I wrote a small script (in Ruby, BSD license) to modify an existing mapnik style by scaling all text sizes, line widths, min/maxscaledenominators etc. It worked quite well for me (using the standard openstreetmap mapnik style) when I tried it some months ago. Link to script: http://www.ancalime.de/images/scalestyle.rb One caveat, though: As the icons are included as pixel graphics, and I do not know of any possiblity to scale them using style file syntax, they are not modified. Thus they will appear much too small on a printed map. If you have better icons, you might be able to adapt the script such that it exchanges yours for the standard ones ... For an own map (which also uses cascadenic style preprocessor to produce the mapnik styles), I created a set of icons in different pixel sizes (converted by inkscape from SVG templates mainly from the OSM SVN), where the size is included as suffix in the filename. With another script (much more complex, so I cannot publish it right away; but if you are interested, I might be able to produce an excerpt of the relevant parts in about two or three weeks) I can parse these filenames, and look for appropriately sized icons in their directory. Hope this helps ... Yours, -- Holger Schoener nume...@ancalime.de ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
[OSM-talk] rendering some large maps, e.g. whole world
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? 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? Can anybody give me a hint on what values to use when printing the whole planet? Thanks for any hints, Torsten. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] rendering some large maps, e.g. whole world
On Sat, Apr 18, 2009 at 9:34 AM, D Tucny d...@tucny.com wrote: 2009/4/18 Torsten Mohr tm...@s.netic.de 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? 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... i've seen two approaches: 1. render to PDF/PS and rasterise/print that at whatever scale you want. this means no mucking about with the style file, but some features (e.g: transparency, text halo-ing) sometimes don't come across the same as they do on the rendered tiles. 2. alter the style file so that everything is ~3 times bigger. this means everything will render right, but is a pain to do by hand. both approaches give comparable results. for the best results, replace the icons with a scalable icon set rendered at 3 times their normal size. 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... i think its more likely to be that -90/+90 lat project to infinity in the mercartor projection. if you want a square image, use -85.0511/+85.0511 lat. see also http://wiki.openstreetmap.org/wiki/Slippy_map_tilenames#X_and_Y cheers, matt ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] rendering some large maps, e.g. whole world
Hello, 2009/4/18 Torsten Mohr tm...@s.netic.de 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. That is correct. I wrote a small script (in Ruby, BSD license) to modify an existing mapnik style by scaling all text sizes, line widths, min/maxscaledenominators etc. It worked quite well for me (using the standard openstreetmap mapnik style) when I tried it some months ago. Link to script: http://www.ancalime.de/images/scalestyle.rb One caveat, though: As the icons are included as pixel graphics, and I do not know of any possiblity to scale them using style file syntax, they are not modified. Thus they will appear much too small on a printed map. If you have better icons, you might be able to adapt the script such that it exchanges yours for the standard ones ... For an own map (which also uses cascadenic style preprocessor to produce the mapnik styles), I created a set of icons in different pixel sizes (converted by inkscape from SVG templates mainly from the OSM SVN), where the size is included as suffix in the filename. With another script (much more complex, so I cannot publish it right away; but if you are interested, I might be able to produce an excerpt of the relevant parts in about two or three weeks) I can parse these filenames, and look for appropriately sized icons in their directory. Hope this helps ... Yours, -- Holger Schoener nume...@ancalime.de ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] rendering some large maps, e.g. whole world
One caveat, though: As the icons are included as pixel graphics, and I do not know of any possiblity to scale them using style file syntax, they are not modified. Thus they will appear much too small on a printed map. If you have better icons, you might be able to adapt the script such that it exchanges yours for the standard ones ... Most of the icons in the standard mapnik style are rendered from the twotone svg set and can be rendered at any required size by modifying the script (i.e. http://svn.openstreetmap.org/applications/share/map-icons/svg-twotone/generatemapniksymbols.sh) Although i've still not got round to modifying this script since the icons where put in to the new hierarchy - you might need to check out an old version of the twotone folder to get it to work. Cheers, -- Brian ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] rendering some large maps, e.g. whole world
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 tm...@s.netic.de 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 talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
