[mapserver-users] Georeferencing a raster without worldfile

Trond Michelsen trondmm-mapserver+2017 at crusaders.no
Fri Dec 1 08:19:14 PST 2017


Hi.

I'm using mapserver 7.0.0

I have about 250.000 raster images that I want to serve through
mapserver. They are all 1195x1550 pixels, and they all cover the exact
same area (UTM33N -75000,6450000,1120000,8000000).  All images has a
resolution of 1km per pixel.

I also have a worldfile that works:
--8<--
1000
0.0
0.0
-1000
-75000
8000000
--8<--

What I want to avoid, is to have one worldfile for each of the 250.000 files. 

I have tried to use a processing directive, like the documentation says:

--8<--
WORLDFILE=<file>
    Specifies an alternative world file (for georeferencing). If a
    path only is specified, the base name of the dataset will be
    appended. The suffix (.wld / .tfw / ...) can be omitted.

    Example:

        PROCESSING "WORLDFILE=/path/"
         or
        PROCESSING "WORLDFILE=/path/file.wld"
         or
        PROCESSING "WORLDFILE=/path/file"
--8<--

But adding 

PROCESSING "WORLDFILE=/path/to/my/worldfile.wld"

to my mapfile has, as far as I can tell, absolutely no effect.


The projection on the layer is defined like this:

  PROJECTION
    "+init=epsg:32633"
  END


If I change that to 

  PROJECTION
    "+init=epsg:32633 +units=km"
  END

My layer will turn up at 0,0,1195000,1550000 in EPSG:32633

In theory, if I added easting and northing to the projection definition, like this:

  PROJECTION
    "+init=epsg:32633 +units=km +x_0=-75000 +y_0=6450000"
  END

It should position itself properly, but proj does not allow easting or
northing to the UTM projections.

The documetation also states:

--8<--
wms_extent

    For Rasters served through WMS, MapServer can now use the
    wms_extent metadata parameter to register the image. If a .wld
    file cannot be found, MapServer will then look for the wms_extent
    metadata parameter and use the extents of the image and the size
    of the image for georegistration.
--8<--

However, if I add 

  METADATA
    "wms_extent" "-75000 6450000 1120000 8000000"
  END

to the layer, it has no effect.


So... What am I doing wrong? How do I get my files to show up where
they're supposed to?


-- 
Trond Michelsen


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