Printing OpenStreetMap Data
Regular maps requested with WMS are not sufficient for high quality prints. If you want to print OpenStreetMap maps e.g. for a general map, you need a map with special requirements. A normal map display out of the application is not sufficient for high quality printing. In order to print the map you need a higher frequency of points than the monitor shows. The frequency of points is indicated in the unit dpi (dots per inch).
If the map is printed with the monitor's screen resolution, the text of the map appears a lot smaller and can hard to read or the map image becomes blurry. With the Omniscale OpenStreetMap WMS you have the possibility to generate optimized maps for printing. For this, we offer two different options depending on your desktop application.
Some applications submit the desired output resolution the WMS request. Our services can then return an optimized image for the requested resolution.
With this approach you can use our map service as usual. No further settings need to be made. One application that supports this function is Quantum GIS (QGIS).
Most other applications do not submit the resolution parameter directly to the map service. These services only enlarge the size of the requested map. Here map services can not decide which resolution the user intends to print.
Therefore it is necessary to use an optimized print service. The service can be added to your application as a regular WMS. The print service directly displays the maps with a higher resolution. So at first the labels and lines will appear much larger on your display. But the print result will show you the desired quality. This also can be seen in the screenshots shown below. Simply add the two services to your desktop application. Prepare your map for printing and just before you print, change to the print service .
Try the optimized print service. The URL for the print service is: https://maps.omniscale.net/v2/<your-api-key>/style.default/dpi.300/map?
You can request other resolutions by changing the 300 (DPI) in the URL.
This method is supported by all GIS and CAD applications, for example:
When printing with 300 DPI all labels and lines will appear in the same size as in the normal view. After printing, you can change back to the normal map service.