> Wondering if when generating overviews we still have a problem similar to > the one you have fixed in 2.0 or some data-updating issue. > > These are my hypothesis on what is going on. > A simple translate with no overviews makes the file ending at 0x7555 with > offset of next IFD saying 0x0000. > When you add overviews, it writes a new IFD at 0x7556 with TAG entries, > then it encodes something and then it writes a new IFD. > At the end, it goes back updating the offset of the 1st overview IFD > (0xBBF0) making the one at 0x7556 being not referred anymore. > Does it make sense? >
With JPEG compression right ? I do reproduce something similar to your findings in 2.1 indeed. This no longer happens in trunk due to related improvements (https:// trac.osgeo.org/gdal/wiki/CloudOptimizedGeoTIFF), I made in the last couple of weeks (using the same trick of creating a in-memory TIFF file to get the JPEG tables and set them direcly on the overview IFD at creation time). Even -- Spatialys - Geospatial professional services http://www.spatialys.com
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