Is there a standardized web feature (WFS) or web processing query to get a single pixel value from a map?

I don't need a whole tile, which seems to be what the WFS and WMS standards are designed for. I just want the pixel value at a specific latitude / longitude.

Is there a standard for this type of query?

  • I would say no, there is no standard way for that. GetFeature info may work with some servers, or GetMap with &WIDTH=1&HEIGHT=1, or WCS GetCoverage. Gdallocationinfo is worth having a look as well gdal.org/gdallocationinfo.html. – user30184 Sep 19 '16 at 19:18
  • Thank you. This seems to be on many people's wish list. gdallocationinfo does the trick, but was hoping for something integrated with the standard. Cheers! – JMC Sep 20 '16 at 0:58
  • Have a look at the SRTM OGC WCS which is desribed at webmap.ornl.gov/wcsdown/wcsdown.jsp?dg_id=10008_1 also search the web for "elevation API". you'll find Google, Mapzen, MapQuest, Bing, et al... – user2856 Sep 20 '16 at 1:27

If you are just interested in the pixel values then an OGC Web Coverage Service (WCS) is what you need. It allows you to request specific areas of larger coverages.

Or it could be done using an OGC Sensor Observation Service (SOS) which gives you a very flexible but standard interface to request spatially and temporally limited results from a service.

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Apparently the answer is no.

WFS and WMS are for serving features and tiles, respectively. There's appears to be no consideration for querying the actual underlying pixels, as is needed for a elevation, terrain, surface or coverage model. Too bad. Hand spun seems to be the order of the day.

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