[GIS] How to render a multi-layered (raster + vector) map to a file (PDF, SVG or JPEG, PNG)

openlayers-2openstreetmappdfpngvector

When using OpenLayers I can compose a map with several layers which is displayed nicely by my browser, but I need to do the same server side (no browser composing the layers), and I'm waiting a image file as output (ie PDF, SVG, JPEG or PNG).

I need to do composition with at least OSM and Vector layer types.

What are my solutions ?

Best Answer

Sounds to me like MapFish Print will do exactly what you want. We use it to do exactly this from a web mapping application.

Related Solutions

[GIS] Options for displaying PostGIS rasters in OpenLayers

Rasters are images, so the best format will be an image format (png/jpg/etc). Geojson is a good format for vectors. You will never see, say, your facebook profile pic be transported back as pure json. Of course, returning a url to an image as json is very very different :)

As far as the jpeg vs png vs any other image format discussion, there are tons of different opinions about it. What it boils down to is that some image formats are lossless while others are lossy. Your decision depends on what you are going to do with the data. For analysis you may probably not tolerate lossy, but for displaying things on the web you would.

Can PostGIS 2.0 generate images? Sure. Look at the Raster output section.

Is this a good idea? It really really really depends on what you are doing. Sometimes generating images may take a really really really long time, and you want to cache them to avoid paying the price of generating them every single time you request them through a web environment. The only "caching" you can do on the PostGIS side is to save the results to a different table and then query the table instead when you need it. Geoserver has an entire infrastructure (GeoWebCache) for doing this.

Do you need GeoServer, probably not - but it makes life a lot easier when you have this middleware that exposes all of your data using OGC web services, does caching, styling of vectors and rasters a whole bunch more things.

[GIS] Options for PostGIS and Mapserver outputing SVG, and client with OpenLayers

You can look here an example of mapserver settings for svg...in mapserver for svg support with wms is not supported yet. You can read here. FORMATOPTION “COMPRESSED_OUTPUT=TRUE” is set MapServer will produce a compressed SVG file (svgz) maybe you will need this too..

and in openlayers showing svg file pls read SVGWeb which has lots of examples for you....

MAP
  NAME 'japan'
  EXTENT 122.935414 24.040589 153.986285 45.554518
  STATUS OFF # we don't want a raster map
  UNITS DD
  SHAPEPATH "/usr/local/apache/htdocs/japan/data/"
  WEB
    HEADER '../header.svg'
    FOOTER '../footer.svg'
    QUERYFORMAT 'image/svg+xml'
  END


LAYER
  CONNECTIONTYPE postgis
  NAME "z9_road"
  STATUS DEFAULT
  CONNECTION "user=postgres dbname=gsi2500 host=10.10.10.100 port=5432"
  DATA "the_geom from (select gid,the_geom from z9_road) as foo using unique gid using SRID=4301"
  TYPE QUERY
  HEADER ../z9_road_header.svg
  FOOTER ../z9_road_footer.svg
  TEMPLATE ../z9_road_template.svg
END
END

i hope it helps you....

Best Answer

Related Solutions

[GIS] Options for displaying PostGIS rasters in OpenLayers

[GIS] Options for PostGIS and Mapserver outputing SVG, and client with OpenLayers

Related Question