Blank Geotiff

[Dominic Lowe]

I've just set up a mapserver WCS  that doesn't seem to want to serve
GeoTiffs...

The WCS is working fine for png/jpeg but whenever I request a Geotiff I
just get back a blank (grey..) screen. 0kb are returned. However I am
sure the GDAL GTiff driver is being recognised as there is no error
message.

i.e.
If I request a "png" I get an image.
If I request a "geotiff" I get a null grey screen.
If I request a "banana" I get an error message.

I've configured GDAL with --with-libtiff=internal and
--with-geotiff=internal. Mapserver is configured --without-tiff (so it
will use the GDAL drivers).

However I have also tried to compile GDAL with external libtiff and
libgeotiff libraries but it doesn't seem to make any difference to the
result..

Output format is declared as:
OUTPUTFORMAT
    NAME Geotiff
    DRIVER "GDAL/GTiff"
    MIMETYPE "image/tiff"
    IMAGEMODE BYTE
    EXTENSION "tif"
END

Any thoughts?

Regards
Dominic