[gdal-dev] Problem with garbage bytes of data after EOI marker in single band JPEG

[Even Rouault]

Le vendredi 13 avril 2012 19:53:41, Ethan Alpert a écrit :
> 
> This has been running for years. Recently a customer who receives these
> started scanning the JPG's for security threats. Turns out that the
> JPG's I've been writing have garbage data after the JPEG EOI marker.
>

This is not garbage, but mask data appended after the JPEG data stream, as 
documented in the JPEG driver doc : 
"""The driver also supports the "zlib compressed mask appended to the file" 
approach used by a few data providers to add a bitmask to identify pixels that 
are not valid data."""

The mask is due to the advertized nodata value in the VRT. You can likely 
remove it by adding <HideNoDataValue>1</HideNoDataValue> in the VRT file under 
the VRTRasterBand element.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.osgeo.org/pipermail/gdal-dev/attachments/20120413/86babb27/attachment-0001.html