[gdal-dev] Reprojecting a tiled dataset

[Frank Warmerdam]

Mike Leahy wrote:
> Hello list,
> 
> I'm wondering if anyone has any recommendations for reprojecting a large, 
> already-tiled RGB GeoTiff image dataset.  It's straightforward enough to script 
> the reprojection of individual tiles, but this leaves black wedges on the 
> sides.  I can merge tiles and add '-n 0' to treat the black wedges as no data, 
> and the merged output looks fine with no visible black strips, but this is a 
> dataset that is of the order of 60GB, so merging all of the tiles takes a 
> particularly long time.
> 
> I thought maybe I could use gdal_retile.py...except that doesn't include an 
> arugment that allow for the exclusion of a particular nodata value in the 
> output.  I figure I could incorporate something to account for nodata into a 
> customized version of gdal_retile.py script...would anyone have any pointers 
> for doing this?

Mike,

I would suggest using gdalbuildvrt to build a virtual dataset
referencing all the tiles, and then gdalwarp that.  I'd suggested
including "-co TILED=YES" in the gdalwarp command to produce an internally
tiled output GeoTIFF file.

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