WCS & pseudocolor/color pallet

[shoaib@…]

From email from Shoaib to MAPSERVER-USERS list:

I was trying out the WCS functionality in Mapserver (running MS4W
7-Feb-2006 rel.)

I am serving a single band image with a pseudocolor table. When I make
a WCS request all's goes well except that image loses the pseudocolor
table (see attached image).

Is there anyway a WCS response can maintain the orignal image's color table?

---------------------------
Relpy from Frank:

Currently there is not.

I would suggest you file a bug report on this.

[shoaib@…]

Example Loss of Color Pallet from a WCS response

[shoaib@…]

The CGI request to Mapserver WCS was as follows:
http://localhost:8080/cgi-bin/mapserv.exe?map=C:/MapFiles/viclandsat.map&mode=map&request=GetCoverage&service=WCS&crs=EPSG:4283&coverage=victoria&FORMAT=GEOTIFF&RESX=0.00031754&RESY=0.00031754&BBOX=144.89354398238416,-37.88435240523746,145.05609280481193,-37.78656912924576

[shoaib@…]

Output of GDALinfo on Orignal Image:
Driver: GTiff/GeoTIFF
Size is 29870, 16511
Coordinate System is:
GEOGCS["GDA94",
    DATUM["Geocentric_Datum_of_Australia_1994",
        SPHEROID["GRS 1980",6378137,298.2572221010002,
            AUTHORITY["EPSG","7019"]],
        AUTHORITY["EPSG","6283"]],
    PRIMEM["Greenwich",0],
    UNIT["degree",0.0174532925199433],
    AUTHORITY["EPSG","4283"]]
Origin = (140.637091,-33.949543)
Pixel Size = (0.00031754,-0.00031754)
Metadata:
  AREA_OR_POINT=Area
Corner Coordinates:
Upper Left  ( 140.6370908, -33.9495435) (140d38'13.53"E, 33d56'58.36"S)
Lower Left  ( 140.6370908, -39.1924681) (140d38'13.53"E, 39d11'32.89"S)
Upper Right ( 150.1220499, -33.9495435) (150d 7'19.38"E, 33d56'58.36"S)
Lower Right ( 150.1220499, -39.1924681) (150d 7'19.38"E, 39d11'32.89"S)
Center      ( 145.3795703, -36.5710058) (145d22'46.45"E, 36d34'15.62"S)
Band 1 Block=29870x1 Type=Byte, ColorInterp=Palette
  Overviews: 7468x4128, 3734x2064, 1867x1032, 934x516, 467x258, 234x129, 14935x8256
  Color Table (RGB with 256 entries)
    0: 238,180,156,255
    1: 255,205,180,255
    2: 197,230,180,255
<...>

Output of GDALinfo on Image produced by WCS GetCoverage :
$ gdalinfo WCS_Response.tif 
Driver: GTiff/GeoTIFF
Size is 512, 294
Coordinate System is:
GEOGCS["GDA94",
    DATUM["Geocentric_Datum_of_Australia_1994",
        SPHEROID["GRS 1980",6378137,298.2572221010002,
            AUTHORITY["EPSG","7019"]],
        AUTHORITY["EPSG","6283"]],
    PRIMEM["Greenwich",0],
    UNIT["degree",0.0174532925199433],
    AUTHORITY["EPSG","4283"]]
Origin = (144.824016,-37.781489)
Pixel Size = (0.00031748,-0.00031748)
Metadata:
  AREA_OR_POINT=Area
Corner Coordinates:
Upper Left  ( 144.8240163, -37.7814895) (144d49'26.46"E, 37d46'53.36"S)
Lower Left  ( 144.8240163, -37.8748281) (144d49'26.46"E, 37d52'29.38"S)
Upper Right ( 144.9865651, -37.7814895) (144d59'11.63"E, 37d46'53.36"S)
Lower Right ( 144.9865651, -37.8748281) (144d59'11.63"E, 37d52'29.38"S)
Center      ( 144.9052907, -37.8281588) (144d54'19.05"E, 37d49'41.37"S)
Band 1 Block=512x16 Type=Byte, ColorInterp=Gray

[warmerdam]

This will not be addressed for 5.0. I shall consider it post 5.0 when I'm working on WCS 1.1 support.

[apetkov]

I am also interested in this enhancement. It would be nice to preserve the values and color table of the original image with a GetCoverage request.