[gdal-dev] Black artifacts with JPEG compression

[Richard Greenwood]

Have you considered using a vector mask, for example, a shapefile on your
server, or depending on your client, maybe a geoJSON file?

On Wed, May 28, 2025 at 12:29 AM carsten.lockenkoetter--- via gdal-dev <
gdal-dev at lists.osgeo.org> wrote:

> Hi Even,
>
> thanks for your response.
>
> I just tried it with WEBP, but I'm getting the following error message:
>
> Warning 6: 'WEBP' is an unexpected value for COMPRESS creation option of
> type string-select.
> Warning 6: driver GTiff does not support creation option WEBP_LEVEL
> ERROR 1: Cannot create TIFF file due to missing codec for WEBP.
>
> The docs says: Requires libwebp >= 0.1.4
>
> I'm using the compiled binaries from gisinternals.com (v.3.9.3) and it
> seems the webp isn't supported with it.
> Do I need to compile the dependency myself and simply copy it into the bin
> folder?
> And how do you compile it? I'm new to this topic—sorry about that.
>
> *Gesendet: *Dienstag, 27. Mai 2025 um 21:43
> *Von: *"Even Rouault" <even.rouault at spatialys.com>
> *An: *"carsten.lockenkoetter at web.de" <carsten.lockenkoetter at web.de>, "
> gdal-dev at lists.osgeo.org" <gdal-dev at lists.osgeo.org>
> *Betreff: *Re: [gdal-dev] Black artifacts with JPEG compression
>
> Am I overlooking something in my process?
>
> No, you're just hitting a fundamental limitation of JPEG compresson
>
> Do you have any ideas on how I can get rid of the artifacts while still
> keeping disk usage low?
>
> Use lossy WEBP compression that fully supports transparency.
>
> -- http://www.spatialys.com
> My software is free, but my time generally not.
>
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>


-- 
Richard W. Greenwood
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