[Gdal-dev] Write with overview updated

[Frank Warmerdam]

Fu Chen wrote:
> Hi!
> I recently use GDAL to update a part of large geotiff file but find 
 > the overview doesn't be updated. I must rebuild overviews of whole file.
> How about add this feature in the GDAL?

Fu Chen,

I gather you are asking that the overviews be updated automatically whenever
data is written to the file, is that right?  I am very hesitant to do that
for performance, and complexity reasons.  However, it is supposed to be
possible to update the overviews "in place" with gdaladdo.  Just request
the existing overview levels, and it should force them to be regenerated.
Let me know if you find otherwise.

When I was at PCI, I didn't update overviews automatically either, but I
did mark them as invalid if raster data was written to a base layer of a
raster with overviews.  I might try something similar in GDAL at some
point.

Best regards,

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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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