8-bit Geotiff ColorInterp=Gray and WCS questions

[Frank Warmerdam]

Nuno GIL wrote:
> Hi listers,
>
> I'm trying to retrieve a 8-bit geotiff from the
> mapserver wcs.
> I've defined, in the map file, the geotiff IMAGEMODE
> as PC256, so I get a "paletted" tiff from the wcs.
> Is there any other IMAGEMODE that I can define in
> order to get a simple gray image without a colour
> palette?

Nuno,

I think IMAGEMODE BYTE is what you would want.

> Width GDALINFO one displays ColorInterp=Gray while the
> other displays ColorInterp=Palette with the 256 colour
> palette.
>
> I would also like to ask if there is any way of
> limiting the size of the user defined bbox on the wcs
> so the user can only D/L a limited portion of the data
> at each time in order not to mess the network.

There is some sort of maximum image request size parameter you
can put in the mapfile for WMS. I am not sure if it applies to WCS
or not.  Hopefully Steve will chip in on this topic.

> In the mosaic we are serving there are some holes
> without image. Can the user get a message back if
> those areas are selected?

My understanding is that the WCS code should support normal "nodata"
handling, and that areas for which there is no data should be set
to the IMAGECOLOR value (or perhaps just the red component).  This area
is pretty fuzzy and I wouldn't be surprised if we need to do some work to
improve it.

Best regards,
--
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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