Hi Jeff, Thank you very much for the detailed response. When I run the commands you provided, everything matches and the output GeoTIFF file definitely has the type "Type=Int16."
I was originally asking why I didn't see that type when querying the server with the sub-datasets returned by this command > gdalinfo "WMS:http://localhost:8080//elev"; but I'm probably just coloring outside the lines of what WMS is meant to support. I think that the next thing I will do is use WCS for this instead. I confess that I went with WMS since I'm more familiar with it. I expected a single-band 16-bit "image" to act like a 2D grid which is what happens when I import "BIL" files or other single-band images. Thanks for stepping me through this and pointing me at WCS. carl On Mon, Oct 11, 2021 at 11:35 AM Jeff McKenna <[email protected]> wrote: > Hi Carl, > > First, welcome to the MapServer community! > > Thanks for the detailed question, and pointing to the source data, this > always helps to give a proper answer. > > You've done well and are very close. Here are some points to consider: > > - the OGC specification for serving raw raster data is actually WCS > (which MapServer does well, see https://mapserver.org/ogc/wcs_server.html > ) > > - but you're right that a cool trick is to use the (more) popular WMS > specification and set an OUTPUTFORMAT in your server's mapfile, to > generate a GeoTIFF through a WMS GetMap request. > > - I see that you've already setup an OUTPUTFORMAT such as: > > OUTPUTFORMAT > NAME "GEOTIFF_16" > DRIVER "GDAL/GTiff" > MIMETYPE "image/tiff" > IMAGEMODE INT16 > EXTENSION "tif" > END > > - now the trick is to call that specific outputformat. I recommend > always testing this at the commandline first, with shp2img (which will > be renamed to 'map2img' shortly, for the MapServer 8.0 release). It > takes a mapfile and generates an output (or gives exact error). > > - since you are using MS4W, just open a CMD window and cd into /ms4w. > Then execute 'setenv.bat' to set necessary paths. Then, in that same > windows, cd to where your mapfile is, and execute the following (notice > the "-i" switch, which requests the named outputformat set in the mapfile) > : > > shp2img -m local.map -o ttt16.tif -map_debug 3 -i GEOTIFF_16 > > - that command should return a draw speed for each layer, and generate > your 16-bit GeoTIFF. And look closely at that response, the first words > will be something like: > > rendering using outputformat named GEOTIFF_16 (GDAL/GTiff) > > Great! That's what we want. > > - once you're satisfied, now we can turn to WMS requests. But always > first start with removing any "WARNING" messages in your GetCapabilities > request, and then also verifying that the <Format> section of that > response includes a listed "image/tiff" format option. (example > GetCapabilities request) : > > > > http://127.0.0.1/cgi-bin/mapserv.exe?map=/ms4w/apps/ticket-wms-gebco-outputformat/local.map&SERVICE=WMS&VERSION=1.3.0&REQUEST=GetCapabilities > > - once you're happy with the GetCapabilities response, then you can try > a GetMap request, that includes "&FORMAT=image/tiff" > > > > > http://127.0.0.1/cgi-bin/mapserv.exe?map=/ms4w/apps/ticket-wms-gebco-outputformat/local.map&SERVICE=WMS&VERSION=1.3.0&REQUEST=GetMap&BBOX=-90,-180,90,180&CRS=EPSG:4326&WIDTH=346&HEIGHT=173&LAYERS=gebco&STYLES=&FORMAT=image/tiff&DPI=96&MAP_RESOLUTION=96&FORMAT_OPTIONS=dpi:96&TRANSPARENT=TRUE > > - or you can stay right there at your commandline, and make that GetMap > request there with the "mapserv -nh QUERY_STRING="" trick, and pipe that > to a new image file, such as: > > mapserv -nh > QUERY_STRING="map=/ms4w/apps/ticket-wms-gebco-outputformat/local.map&SERVICE=WMS&VERSION=1.3.0&REQUEST=GetMap&BBOX=-90,-180,90,180&CRS=EPSG:4326&WIDTH=346&HEIGHT=173&LAYERS=gebco&STYLES=&FORMAT=image/tiff&DPI=96&MAP_RESOLUTION=96&FORMAT_OPTIONS=dpi:96&TRANSPARENT=TRUE" > > > getmap.tif > > Hope that helps. > > Also thanks for the positive feedback on MS4W, its goal is to serve big > data fast for organizations, on enterprise Windows servers, and it > sounds like it has met your needs well. Look for a big MS4W release soon > ;) > > And a happy (Canadian) Thanksgiving holiday to you. > > -jeff > > > > -- > Jeff McKenna > GatewayGeo: Developers of MS4W, MapServer Consulting and Training > co-founder of FOSS4G > http://gatewaygeo.com/ > > > > On 2021-10-07 8:12 p.m., Carl Godkin wrote: > > Hi, > > > > I'm new to mapserver but fairly experienced with GDAL. I hope that > > someone can explain where I've gone wrong with setting up WMS. > > > > I followed the instructions here > > [https://worldwind.earth/elevation-server.html > > <https://worldwind.earth/elevation-server.html>] almost exactly to set > > up a WMS server and it sort of works. (I am using MS4W actually, so I > > didn't install Apache & Mapserver as that page described and of course I > > made a few other adaptations for Windows.) > > > > I downloaded the GEBCO tiles from here > > [https://www.gebco.net/data_and_products/gridded_bathymetry_data/ > > <https://www.gebco.net/data_and_products/gridded_bathymetry_data/>] > > without any problems. > > > > What I don't understand is that while the GEBCO GeoTIFF files that I am > > using have one band that gdalinfo describes as > > > > Band 1 Block=512x512 Type=Int16, ColorInterp=Gray > > > > when I look at the WMS bands using gdalinfo, I see three byte-sized > bands: > > > > Band 1 Block=1024x1024 Type=Byte, ColorInterp=Red > > Band 2 Block=1024x1024 Type=Byte, ColorInterp=Green > > Band 3 Block=1024x1024 Type=Byte, ColorInterp=Blue > > > > I'd really like to get 16-bit integer elevations from my WMS server but > > I don't know why this didn't just happen or how I mis-configured things > > to make it not happen. > > > > I know these are not complete details, but rather than write a novel for > > my first post here, I'm hoping someone can suggest where the problem > > might be or suggest some further documentation to read. > > > > Thanks very much, > > carl > > > > > > > _______________________________________________ > MapServer-users mailing list > [email protected] > https://lists.osgeo.org/mailman/listinfo/mapserver-users >
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