ES:Osmarender/Información práctica

El proceso Osmarender

Esta página explica cómo obtener los datos existentes osm de la web y cómo convertirlo en una imagen SVG a través de Osmarender.

proceso básico de Osmarender de la transformación XSLT:

 osm-map-features.xml ==xslt==> svg

Es la hoja de estilo XSL en sí mismo, se hace referencia en el archivo "data.osm".

Requerimientos

Usted necesita básicamente:

1. An openstreetmap.org account
2. A couple of files which describe the conversion process
3. An xslt processor of your choice (mentioned below) which does the actual conversion
4. The OSM data of the area you want to render
5. A recent web browser or vector image editor.

Descarga del software

Osmarender isn't a usual application to be downloaded. Instead it's a set of files which let you perform an XSL transformation. All of the required files can be found in the Subversion repository, accessible via http://svn.openstreetmap.org/applications/rendering/osmarender/ . (Note that there are also directories called osmarender6 which contain older versions of Osmarender. These are not compatible with the data format used in OpenStreetMap API version 0.6.)

There are two ways to get the Osmarender files. Either you use the subversion program (see Getting The Source for details) or you download all the files individually:

Right click on each file and save them all to the same directory. You need at least

1. The rules file, called osm-map-features-z17.xml.
2. The style sheet file, called osmarender.xsl.

If you are using Linux or Unix you might also want the

1. osmarender and
2. xsltrans shell scripts.

La obtención de los datos del mapa que desea hacer

After the files mentioned above have been downloaded, you need the OSM data of the area you want to render. It needs to be downloaded and saved to the same directory where you saved all the other files. The name of the data file must read as data.osm. There are several methods to get the data:

• You can download the data with your preferred web browser. This can last a while, depending on the size of the area you try to download and the amount of map elements found in it.

1. In your browser, enter the following URL while adjusting the bounding box coordinates to get the area you are interested in: http://www.openstreetmap.org/api/0.6/map?bbox=-0.5,51.3,-0.4,51.4 The bounding box should be (west edge), (south edge), (east edge), (north edge). Coordinates south of the equator are negative, and west of Greenwich are negative. You can determine the area to download from the main OSM map by examining the URL for the 'View' tab, and pasting this into the 'download' dialog in JOSM. The URL contains the location of the centre of the view and the zoom level.
2. The download may take a while, so please be patient. After it is complete, right click in your browser and choose »View Page Source«
3. From the menu »File« choose »Save Page As...«. Save it as data.osm to the directory containing all the other downloaded files

• If you are already familiar with editing, you can even use JOSM to save the data.

1. Simply save your downloaded data as data.osm in the directory containing all the other files
2. You also can save it under any other filename, but you will then need to amend the data="file" line in the top section of the rules file. Alternatively, under UNIX-based operating systems (Linux, BSD, UNIX, Mac OS X), you can create a symbolic link to it by using the command "ln -s <existing filename> data.osm".

Render de los datos

Now that all files have been downloaded, you can use one of the following methods to convert the osm data file to an SVG image file called map.svg.

Xalan-J

Xalan-J is an xslt processor implemented in Java. It provides a java command line application, so if you have JDK or JRE already installed, you can perform the following steps:

1. Download and install xalan from http://xml.apache.org/xalan-j/downloads.html
2. Start your favorite terminal. E.g. on Windows, open the MS-DOS prompt
3. cd to the directory containing all the downloaded files
4. Run the following command:

   • java -cp c:\path\to\xalan.jar org.apache.xalan.xslt.Process -in osm-map-features-z17.xml -out map.svg

XRay2

The XRay2 XML editor is from 2002, but has an XSLT transformation engine that runs osmarender fine. It is available for download from http://www.architag.com/xray Like Instant Saxon, xRay2 runs only on the Windows platform.

Saxon

Saxon is another XSLT processor implemented in Java and simultaneously implemented in .NET framework, too. Saxon runs faster than Xalan-J and it supports XSLT 2.0, XQuery 1.0 and XPath 2.0. There are 3 versions, an open source version Saxon Home Edition (Saxon-HE) a professional edition (Saxon-PE) and an enterprise version (Saxon-EE). The opensource version has functions enough to process the osmarender.xsl.

1. Download and install Saxon-HE (Opensource version) from http://saxon.sf.net
2. open your terminal
3. cd to the directory containing all the downloaded files
   • Run the following command (for Java implementation):

   • java -jar c:\path\to\saxon9he.jar -t -xsl:osmarender.xsl -s:osm-map-features-z17.xml -o:map.svg 

   • Run the following command (for .NET implementation):

   • \saxon\bin\Transform -t -xsl:osmarender.xsl -s:osm-map-features-z17.xml -o:map.svg 

However I have not been able to get recent versions of osmarender to run all the way through due to a node-set error (it runs fine under Xray2)

XML starlet

• On Debian GNU/Linux / Ubuntu:

1. If not installed, install XMLstarlet
   1. on Debian GNU/Linux as root by invoking the command :

      apt-get install xmlstarlet

   2. on Ubuntu by invoking the command :

      sudo aptitude install xmlstarlet

2. cd to the directory containing all the downloaded files
3. Render the map (The rules file osm-map-features-z17.xml can be replaced with a custom rules file if you want different output)
   1. with osm-map-features-z17.xml, run the following command:

      xmlstarlet tr osmarender.xsl osm-map-features-z17.xml > map.svg

• On Windows:

1. Download win32-zip file from here
2. Decompress to (e.g.) c:\xml
3. From the directory where you installed Osmarender run command:

   c:\xml\xml tr osmarender.xsl osm-map-features-z17.xml > map.svg

4. map.svg is created in the current (Osmarender) directory

• On Mac OS X:

1. Install XMLStarlet by invoking the command :

   fink install xmlstarlet

2. Run the following command:

   xml tr osmarender.xsl osm-map-features-z17.xml > map.svg

   Note that the command is actually 'xml' rather than 'xmlstarlet' as above.

MSXML

For Windows users, Microsoft offers an XML parser / XSLT processor called MSXML. To use it do the following: NOTE: THIS DOES NOT WORK WITH OSMARENDER 4, but should work with Osmarender 5 (windows users might want to see NXSLT2 below)

1. Download MSXML 6.0 from here and install it.
2. Then you need to place the Command Line Transformation Utility (msxsl.exe) in your windows/system32 directory, download it from here
3. To run the transform at a DOS / command prompt, cd to directory containing all the other downloaded files
4. Now run the following command:

   msxsl osm-map-features-z17.xml -pi -o map.svg

5. Don't forget the -pi option to force the use of an external stylesheet. Otherwise it would look for it on the command line

NXSLT2

This needs the Microsoft NET2 Framework to be installed first.

Then install NXSLT2 from the download link in the bottom right of the relevant box.

Once installed a command such as

nxslt2 osm-map-features-z17.xml -pi -o map.svg 

will produce an SVG file from the data file specified in standard.xml.

Initial tests using Osmarender4 seem to indicate this produces a correct SVG file.

xsltproc

1. On Linux and Mac OS X 10.4 (Tiger) and newer, xsltproc is usually installed. If not, please use the installation tools of your distribution to install it. xsltproc is part of Libxslt, which is part of the GNOME XML parser.
2. Open your preferred terminal emulation
3. cd to the directory containing all the previously downloaded files
4. Now invoke the following command:

   xsltproc osmarender.xsl osm-map-features-z17.xml > map.svg

   or

   xsltproc -o map.svg osmarender.xsl osm-map-features-z17.xml

   If you are using xsltproc from within an SVN checkout of osmarender4, use the following command:

   xsltproc --path . --path ./symbols rules/standard.xml > map.svg

It is even possible to use xsltproc on Windows by installing Cygwin, a Unix-like compatibility layer. Simply select the package called libxslt in the Cygwin installer.

Altova XMLSpy

1. Open osm-map-features-z17.xml
2. Press F10
3. Wait!
4. Correct any errors in the output (all my railway stations have two r-attributes) before saving as whatever.svg

Viendo la imagen SVG

After all those efforts, you might want to open and view the resulting map.svg image file.

Firefox/Chrome/Safari/Opera

These browsers will display the map very nicely. Just open the file map.svg directly. Firefox version 1.5 and earlier does not display road names.

Internet Explorer 9

IE9 Previews are not supported at the moment.

Internet Explorer con Adobe SVG Viewer

Should render the map very nicely. When you have it zoomed / panned to your liking, use shift + printscreen to capture a screenshot, and paste it into your favourite imaging application.

Inkscape

Inkscape 0.42 and later should display the map very nicely. On small maps, you may need to manually resize the logos so they don't blot out your map.

When exporting to png (File -> Export Bitmap), you may need to alter the DPI setting to get the image to come out at the required size and resolution.

It is also possible to run inkscape on the command line to output a .png -

inkscape -D -e output.png map.svg 

use -d 300 switch to specify 300 DPI

For Windows systems, you have to provide full path name to inkscape.exe, input and output file within the command line. Pathnames with blanks require quotation marks around path and filename.

Batik

The rasterizer from Batik should render things well, but it can be very fiddly to get the width, dpi etc right so that the png fits everything onto it.

librsvg2

rsvg from librsvg2 (librsvg2-bin on some platforms) will produce nice pngs.

Adobe Illustrator

Illustrator CS includes SVG import and will display files produced with Osmarender. However, even with CS3, the road names render unsatisfactorily (all characters are vertical rather than following a path) and the shading around residential streets can be severely offset.

ImageMagick

ImageMagick is a command-line-tool-collection to modify picture-data. To render SVG to any other (raster)format, use the comand "convert". The parameter "-density" sets the resolution of the output-image in DPI, the parameter "-scale" defines the size of the output-image in pixel. If you want your map to be 500px wide and very high quality, you might use

convert -density 600 -scale 500 map.svg map.png

However, it seems that ImageMagick doesn't render streetnames yet.

Y ahora qué?

You could upload a screenshot or bitmap-export of the SVG to this wiki for all to see. You might also like to read the Osmarender/Tips page to tweak the output of Osmarender.

Cuestiones generales

Until the data.osm mentioned is processed completely, there will be no output other than some processing messages. So when trying things out, it is recommended that you don't use a too large / too complex part of the map, otherwise the transformation can take quite a while. Tiles@home tries to circumvent that issue by downloading only the area of the tile that is rendered (with all paths that are within that area, see Rendering large areas).

Véase también

• Osmabrowser, which aims to provide a user-configurable front-end to Osmarender.
• OSM@home which runs osmarender for each UK city, and displays the results on a website
• or/p from tiles@home project