-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hello Developers,
two years ago I implemented an extension to the old WMS plugin to handle NASA's "Tiled WMS" for Landsat. It is not possible to apply these change to the current version because a lot of things have changed. (This was implemented shortly after my changes and the problems with the Landsat server were gone. That's why I did not try to integrate my modifications with the new WMS plugin.) Currently the same problems are present with the Landsat WMS server. It does not respond to normal WMS requests, but it seems to process "Tiled WMS" requests. (see http://onearth.jpl.nasa.gov/) So I tried to rework my changes for the current WMS plugin, but I was not successful until now. I can already do these things: Send a GetCapabilities request and parse the response to find out if the server supports NASA's tiled WMS. Send a GetTileService request and parse the response to get the set of supported tile patterns. Compare a normal WMS request with the available patterns and find the best matching pattern. (Currently I choose the lowest available resolution from the patterns that is higher than or equal to the requested resolution, if available, otherwise I choose the highest resolution that is smaller than the requested one.) - From the best pattern and the original request construct a list of WMS requests that will cover at least the requested area. To use this tiled access I normally have to fetch more than one image (tile) to fill the requested area. I did not find out how to integrate this into the current WMS plugin. (With the old WMS plugin I simply fetched all images in a loop and created more than one GeorefImage.) When I open a WMS layer with a high resolution and then zoom out, I can see that the plugin fetches the visible area in smaller parts. The WMS plugin seems to handle something like tiles in this case. Maybe this feature can be used for the Tiled WMS access. Unfortunately I don't understand how exactly this works. Who could explain or discuss some internals of the WMS plugin? Bodo -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) iEYEARECAAYFAkxV2ZsACgkQnMz9fgzDSqdK0QCeOAFOUdb/Rg7HfavLC/MFOxdS uu4AnR2tOvxIkdHANi7m3q18KKgEQwGI =QUy0 -----END PGP SIGNATURE----- _______________________________________________ josm-dev mailing list josm-dev@openstreetmap.org http://lists.openstreetmap.org/listinfo/josm-dev
