[gdal-dev] garbled output from gdaladdo in geopackage

[Even Rouault]

Le jeudi 14 janvier 2016 12:07:44, Thomas Sevaldrud a écrit :
> Hi,
> 
> I've been using the new GeoPackage raster support in 2.0.1, and have
> noticed some strange output from gdaladdo on certain datasets.
> 
> When producing an overview tile which is on the edge of the dataset, so
> that it is not entirely covered by its child tiles, I get random data in
> the parts of the image which is outside the coverage.

Part of tiles outside the coverage would be supposed to be at value 0 (and if 
using PNG tiles with alpha=0)

> 
> I'm not sure how gdaladdo does this, but for standard x2 tile pyramids I
> assume it makes each overview tile by subsampling its four child tiles. In
> this case, not all four child tiles have data and the output in the missing
> areas becomes garbled.
> 
> Is this a known issue? 

Not that I'm aware of.

> Any workarounds?
> 
> If necessary, I can provide a test case to reproduce it.

That might indeed be useful. Please file a ticket about that.

Even

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