[mapserver-users] Re: problem with mercator projection

[Rahkonen Jukka]

Hi,

You perhaps want to achieve a map presenting the whole world once and then some extra from the second round in the margins like http://www.openstreetmap.org/?lat=59&lon=-39&zoom=1&layers=M?  It might well be that the transformation functions consider that for EPSG:3395 the maximum values really are the bounds reported at http://spatialreference.org/ref/epsg/3395/ and values outside the value range are invalid. I have no idea about how you could get your map out from WMS.  Could you consider composing it from pieces somehow?

-Jukka Rahkonen-


________________________________
Lähettäjä: mapserver-users-bounces at lists.osgeo.org [mailto:mapserver-users-bounces at lists.osgeo.org] Puolesta fred p
Lähetetty: 23. syyskuuta 2011 11:10
Vastaanottaja: mapserver-users at lists.osgeo.org
Aihe: [mapserver-users] Re: problem with mercator projection

Hello
Nobody has got an idea whether I am wrong somewhere or there is a problem in the image or ... ?
I add the result is OK in EPSG:4326 whatever the bbox is and it is OK too in EPSG:3395 provided the extent longitude is smaller than 360°. However when it is higher...
Thanks in advance

2011/9/21 fred p <mapoubelle22 at gmail.com<mailto:mapoubelle22 at gmail.com>>
Hello !

I am trying to serve an image in Mercator projection (EPSG:3395) with an extent larger than "360° in longitude" but I get a truncated and reversed in longitude image.
Do I make a mistake somewhere?
Thanks for your help

The mapfile content and the gdalinfo output on the original image are given below.


Mapserver version: 6.0.1

Call to mapserver:
/path/to/mapserv -nh "QUERY_STRING=map=/tmp/world.
map&service=wms&LAYERS=countries&FORMAT=image/png&SERVICE=WMS&VERSION=1.3.0&REQUEST=GetMap&STYLES=&SRS=epsg:3395&BBOX=-26080550.098232,-15000000,26080550.098232,15000000&WIDTH=885&HEIGHT=509" > foo.png

Content of the mapfile:
MAP
  EXTENT -180 -90 180 90
  IMAGECOLOR 255 255 255
  IMAGETYPE agg
  STATUS ON

  OUTPUTFORMAT
    NAME "agg"
    MIMETYPE "image/png"
    DRIVER "AGG/PNG"
    EXTENSION "png"
    IMAGEMODE "RGBA"
    TRANSPARENT TRUE
    FORMATOPTION "INTERLACE=false"
  END

  PROJECTION
    "init=epsg:4326"
  END

  WEB
    METADATA
      "wms_srs"    "epsg:4326 epsg:3395 epsg:900913 epsg:3995"
      "OWS_ENABLE_REQUEST"    "*"
    END
  END

  LAYER
    DATA "/tmp/world.tif"
    NAME "countries"
    PROJECTION
      "init=epsg:4326"
    END
    STATUS ON
    TYPE RASTER
  END

END

Output of gdalinfo command:
$ gdalinfo /tmp/world.tif
Driver: GTiff/GeoTIFF
Files: /tmp/world.tif
Size is 1000, 500
Coordinate System is:
GEOGCS["WGS 84",
    DATUM["WGS_1984",
        SPHEROID["WGS 84",6378137,298.257223563,
            AUTHORITY["EPSG","7030"]],
        AUTHORITY["EPSG","6326"]],
    PRIMEM["Greenwich",0],
    UNIT["degree",0.0174532925199433],
    AUTHORITY["EPSG","4326"]]
Origin = (-180.000000000000000,90.000000000000000)
Pixel Size = (0.360000000000000,-0.360000000000000)
Metadata:
  TIFFTAG_DOCUMENTNAME=/tmp/world.tif
  TIFFTAG_XRESOLUTION=72
  TIFFTAG_YRESOLUTION=72
  TIFFTAG_RESOLUTIONUNIT=2 (pixels/inch)
  AREA_OR_POINT=Area
Image Structure Metadata:
  INTERLEAVE=BAND
Corner Coordinates:
Upper Left  (-180.0000000,  90.0000000) (180d 0'0.00"W, 90d 0'0.00"N)
Lower Left  (-180.0000000, -90.0000000) (180d 0'0.00"W, 90d 0'0.00"S)
Upper Right ( 180.0000000,  90.0000000) (180d 0'0.00"E, 90d 0'0.00"N)
Lower Right ( 180.0000000, -90.0000000) (180d 0'0.00"E, 90d 0'0.00"S)
Center      (   0.0000000,   0.0000000) (  0d 0'0.01"E,  0d 0'0.01"N)
Band 1 Block=1000x8 Type=Byte, ColorInterp=Gray



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