[mapserver-users] strange raster problem

[Bart van den Eijnden (OSGIS)]

Hi list,

we have a strange problem with an ArcSDE raster layer. At certain zoom
levels the pixels are very coarse. Zooming out one level the pixels are
okay, however the colour is not.

You can see this in the following images, the first one is zoomed out and
everything is okay (except the colours since the image should be mostly
black):

http://www.osgis.nl/download/mapserver/rws1.png

However when zooming in one level, we obtain the following situation:

http://www.osgis.nl/download/mapserver/rws2.png

Does anyone have an explanation for this? Using Mapserver trunk from about
3 months back and GDAL 1.7.2.

This is the info from ArcCatalog about the raster layer:

<TreeList><Data_Source><Raster>BODEM.DNZ_GRINDPERCENTAGE_TOT_15CM</Raster><Data_Type>SDE
Raster</Data_Type><Server>geodatabase.ad.rws.nl<User>RWS_LEZEN</User><Instance>5151\tcp</Instance><Database></Database><Version>SDE.DEFAULT</Version></Server></Data_Source><Raster_Information><Columns_and_Rows>1161,
2021</Columns_and_Rows><Number_of_Bands>1</Number_of_Bands><Cellsize__X._Y_>250.00000000000011,
250</Cellsize__X._Y_><Uncompressed_Size>8.95
MB</Uncompressed_Size><Format>SDR</Format><Source_Type>continuous</Source_Type><Pixel_Type>floating
point</Pixel_Type><Pixel_Depth>32
Bit</Pixel_Depth><NoData_Value>-3.402823E+38</NoData_Value><Colormap>absent</Colormap><Pyramids>level:
4, resampling: Nearest
Neighbor</Pyramids><Compression>LZ77</Compression></Raster_Information><Extent><Top>6199911.5560208503</Top><Left>459782.82782689098</Left><Right>750032.82782689109</Right><Bottom>5694661.5560208503</Bottom></Extent><Spatial_Reference>ETRS_1989_UTM_Zone_31N<Linear_Unit>Meter
(1.000000)</Linear_Unit><Angular_Unit>Degree
(0.017453292519943299)</Angular_Unit><False_Easting>500000</False_Easting><False_Northing>0</False_Northing><Central_Meridian>3</Central_Meridian><Scale_Factor>0.9996</Scale_Factor><Latitude_Of_Origin>0</Latitude_Of_Origin><Datum>D_ETRS_1989</Datum></Spatial_Reference><Statistics><Band_1><Build_Parameters>skipped
columns:1, rows:1, ignored value:
</Build_Parameters><Min>0.5</Min><Max>59.80879974365234</Max><Mean>0.831969292920005</Mean><Std_dev.>2.825845448840229</Std_dev.><Classes>0</Classes></Band_1></Statistics></TreeList>

The LAYER definition is:

LAYER
 CONNECTIONTYPE SDE
    DATA
"SDE:xxxxx.ad.rws.nl,port:5151,5151,RWS_LEZEN,XXXXXX,BODEM.DNZ_GRINDPERCENTAGE_TOT_15CM,RASTER"
 DUMP TRUE
 EXTENT 459782.827826891 5694661.55602085 750032.827826891 6199911.55602085
 NAME "BODEM.DNZ_GRINDPERCENTAGE_TOT_15CM_5925"
 PROCESSING 'CLOSE_CONNECTION=DEFER'
 PROCESSING 'DITHER=NO'
 PROCESSING 'NODATA=NODATA'
 PROCESSING 'SCALE_1=0.5,59.8087997436523'
 PROCESSING 'BANDS=1'
 PROCESSING 'LOAD_FULL_RES_IMAGE=NO'
 PROCESSING 'LOAD_WHOLE_IMAGE=NO'
 SIZEUNITS PIXELS
 UNITS METERS
 STATUS ON
 TEMPLATE 'blank.html'
 TOLERANCE 5
 TOLERANCEUNITS PIXELS
 TYPE RASTER
 PROJECTION
  'init=epsg:25831'
 END
 METADATA
  'wms_title' 'Grindpercentage, stretched'
  'wms_layer_group' '/Grindpercentage_ NCP'
  'wms_metadataurl_format' 'text/xml'
  'wms_metadataurl_href'
'http://test.intranet.rijkswaterstaat.nl/services/geoservices-update/metadata/BODEM.DNZ_GRINDPERCENTAGE_TOT_15CM'
  'wms_metadataurl_type' 'TC211'
  'wcs_abstract' 'noordzee grind en zand raster'
  'wcs_bandcount' '1'
#  'wcs_description' 'noordzee grind en zand raster' # Optional
  'wcs_extent'
'459782.827826891,5694661.55602085,750032.827826891,6199911.55602085'
  'wcs_formats' 'GTiff,MrSID,ECW'
  'wcs_keywords' 'RWS,Rijkswaterstaat,noordzee grind en zand
raster,BODEM.DNZ_GRINDPERCENTAGE_TOT_15CM_5925'
  'wcs_label' 'Grindpercentage, stretched' # Required
  'wcs_metadatalink_format' 'text/xml'
  'wcs_metadatalink_href'
'http://test.intranet.rijkswaterstaat.nl/services/geoservices-update/metadata/BODEM.DNZ_GRINDPERCENTAGE_TOT_15CM'
  'wcs_metadatalink_type' 'TC211'
  'wcs_name' 'BODEM.DNZ_GRINDPERCENTAGE_TOT_15CM_5925'
#  'wcs_nativeformat' 'Raster' # Optional
  'wcs_rangeset_label' 'Grindpercentage, stretched'
  'wcs_rangeset_name' 'BODEM.DNZ_GRINDPERCENTAGE_TOT_15CM_5925'
 END
 PROCESSING 'SCALE_BUCKETS=256'
CLASS
 STYLE
  COLORRANGE 0 0 0 255 255 255
  DATARANGE -4.81972160476045 6.48366019060046
  RANGEITEM "pixel"
 END
END
END

TIA.

Best regards,
Bart