[mapserver-users] Open Source solution to display PNG maps converted from SVG in a map viewer with labels and possibly tiles

[Andreas Neumann]

So, if I understand you correctly, your original map data is stored in 
SVG files.

In that case you can use Apache Batik to render into georeferenced PNG 
files (if your SVG data is georeferenced). You can trigger this 
rasterization process whenever there was a change in the SVG data. This 
georeferenced raster data can be fed into UMN Mapserver for fast 
delivery. My guess is, while the quality of the Apache Batik rendering 
process is excellent, it won't be as fast as the UMN Mapserver, when 
delivering maps.

Alternatively, you can consider to serve the SVG data directly, without 
going through PNG files. You can also combine SVG with Postgis where the 
vector data is stored in Postgis and the SVG is generated on the fly. 
You can see an example of this approach at 
http://www.carto.net/williams/yosemite/ - for bigger SVG files it is 
certainly faster if you store your geodata in a spatial database and 
deliver customized extents, simplified versions and sub-selects 
appropriate to the chosen mapscale.

Hope this helps,
Andreas


Jeremy Short wrote:
> My goal is to render an SVG image map to PNG to display on our website 
> within a mapviewer of some sort with panning and zooming capability. 
> We have many maps. I want to use an Open Source solution. Our web 
> server is running Apache.
>
> Additionally we want to add a "layer" of text labels which will not 
> get bigger when we zoom in. Too, since we have large pictures so they 
> don't degrade when one zooms in, we would like to explore the ability 
> to send only "tiles" of the map picture if it's required.
>
> What I have found thus far:
>
> 1. Using OpenLayers as a client gives us the ability to load a PNG 
> file, pan, and zoom.
>
> 2. For the ability to add layers of text labels and transport tiles of 
> data I explored the possiblity to use Mapserver. It appears Mapserver 
> requires a map file like an SHP file as input and it will output a 
> PNG. I would like to feed it as input a PNG file but I don't know if 
> Mapserver is designed for this.
>
> Looking further into this I see one can possibly use a tool like gvSIG 
> or AB Viewer to translate a PNG to a SHP file but I want to automate 
> the process without this extra step because people will be modifying 
> the SVG file periodically.
>
> There seems like there must be a better way to accomplish what I want 
> which is to render PNG images in a client web browser with the ability 
> to navigate within the map and to render text labels and transport 
> tiles of information. Is there?
>
>
>


-- 
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Andreas Neumann
Institute of Cartography
ETH Zurich
Wolfgang-Paulistrasse 15
CH-8093  Zurich, Switzerland

Phone: ++41-44-633 3031, Fax: ++41-44-633 1153
e-mail: neumann at karto.baug.ethz.ch
www: http://www.carto.net/neumann/
SVG.Open: http://www.svgopen.org/
Carto.net: http://www.carto.net/