[gdal-dev] Converting ecw to tif for Geoserver

[Andrea Aime]

On Sun, Feb 10, 2013 at 8:54 PM, Paul Meems <bontepaarden at gmail.com> wrote:

> Thanks Andrea,
>
> I didn't understand that the first time.
> So there is no way to have the raster on top of another layer without
> getting white areas?
> In that case I will upload the smaller tiff file ;)
>

I've tried just to see what happens, GeoServer ends up thinking the mask is
an overview
and displays it when zoomed out, showing the actual data when zoomed in.
It should be possible to modify the TIFF reader to handle the transparency
mask accordingly,
but it's going to take some work.

Another option could have been to set the "input transparent color" in the
raster configuration
to white, but unfortunately the jpeg compression alters pixels and you'll
get many almost
white pixels in the jpeg file that won't be masked this way.

The image mosaic code also has the ability to support "footprint" files in
wkb format (so, as
vector masks), but that's an undocumented functionality, one that I don't
know if it's user
accessible, or must be setup programmatically (the only times I've seen it
used, the
footprints were programmatically loaded into the mosaic API).

Long story short, I don't believe there is an easy way to get what you
want, without making
some changes to the way GeoServer reads TIFF files.

Cheers
Andrea



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Ing. Andrea Aime
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